Overview

All work has to comply with New Zealand building regulations. This design is intended for construction anywhere in the country. The type of permit is called MultiProof. Any site-specific concerns will be dealt with separately at time of construction.

The concept is to create the best living environment that is cost efficient, zero energy running costs and meets as many eco-friendly targets as possible. There is a tradeoff between capital cost, payback period and environmental issues. I have tried to find the intersection of these. I am not obsessed with meeting any particular eco initiative but meeting the challenge to provide the most cost effective, flexible and highest quality of life house with a general 10-year payback period for insulation, solar etc. Electricity is $0.28NZD/kW

Currently, this sort of housing costs $4,000NZD+ per square metre. If there was a way to halve this cost – we could afford to build twice as many houses, especially for the vulnerable members of society.

I sat down with an open mind and looked for ways to solve the crux of the issue – Cost. Currently, cost is controlled by the tender process using existing products and methods rather than by reconsidering the materials and construction methods. All images are suggested solutions or concept illustrations.

A commercial building is designed as the optimum cost-efficient construction method for the landlord to provide a work environment for occupants. This building is then wrapped with a decorative façade. This design follows the same principles.

All water, electrical and sewerage service inlets and outlets are external to the building. There are no ‘Under the house’ excavations. Internet and power are cabled internally either in-wall or via trunking (Wireless does not work well inside a metal building).

Rapid implementation on cheaper land is ideal as no power, water or septic infrastructure is required. This sidesteps the local Government delay in providing infrastructure to sites. Shared power systems average the power generation and usage. This makes the design ideally suited to multiple single level dwellings on a single site. These dwellings are designed for disabled access by default (Whether or not the occupant is disabled). These are ‘Whole of life’ houses, suitable for young singles, families, couples, the elderly or the disabled. By building a ‘Whole of life’ house that caters to every stage in life, people are better able to create a community and engage locally as their life is spent living instead of facing the stress and cost of constant moving, buying or selling. There are immense savings to the Government and Councils who do not need to reticulate services to the properties.

This design draws concepts from:

  • Commercial buildings
  • Heated floor underlayment in the UK
  • Roading foundations
  • Commercial cool stores
  • Passive ventilation techniques
  • Revolutionary fire suppression system from Switzerland
  • Off grid design by default
  • Disabled, elderly living requirements.

Targets I’d like to meet or exceed if possible:

  • PassiveHaus® thermal efficiency
  • LEED Certification
  • Lifemark® Standard and ‘Barrier free’ housing for disabled people
  • Living Building Challenge – International green building standard.

A lot of aspects of this design are unknown in New Zealand, so a high level of proof is required with detailed workings and cross references. I have included references which may help with background information and provide an understanding of the mindset of the regulations, regulators and compliance inspectors. There is a lot of educational and psychological investment in current methods, from Regulators, Teachers, Builders, Inspectors and Corporate interests who are used to existing methods, suspicious of new ideas and resistant to change.

Reference is made to ‘Large’ and ‘Small’ houses in places throughout this document.

The ‘Small house’ is the focus of this job. It is:

  • 15m x 15m
  • 3 bedroom
  • 2 bathroom (Master ensuite and ‘Jack and Jill’ with laundry for Guests)
  • 1 garage (5m wide to allow for disabled access)
  • Back door is from laundry. Door on North side to decking/Garden
  • Single level dwelling
  • Shared off-grid power supply
  • Own septic system
  • Own rainwater harvesting
  • Monopitch roof – 3m to 4m slope
  • Oriented: North – Lounge, Kitchen, East – Entry, South – Garage, West – Bedrooms, Laundry, Bathrooms

The ‘Large house’ is the same, but:

  • Larger – 25m x 20m
  • Double garage (2 doors)
  • 2 extra internal spaces (Non-living)
  • Workshop – 50m2
  • Sunroom / Conservatory
  • Guest floor ‘Mezzanine’ above an office on the East side
  • Linear actuator driven front door (Like garage)
  • Monopitch roof – 3m to 6m slope
  • Oriented: North – Lounge, Kitchen, East – Entry, Office and Guest floor, South – Garage, West – Bedrooms, Laundry, Bathrooms

Climate

NZ is a seismic country which has regular 4-5 Richter earthquakes and occasionally, 7.

Areas near Rotorua (North Island) also have geothermal considerations with high Sulphur emissions. Geothermal compliance can be left for the time being as it is a relatively small area of the country. Do note any possible issues for this aspect.

The climate of New Zealand is varied due to the country’s diverse landscape. The climate is complex and varies from warm subtropical in the far north to cool temperate climates in the far south, with severe alpine conditions in the mountainous area. Most regions of New Zealand belong to the temperate zone with a maritime climate (Köppen climate classification: Cfb) characterised by four distinct seasons. Winters are relatively mild and summers comparatively cool. The main contributing factors are the Pacific Ocean and latitude, although the mountain ranges can cause significant climate variations in locations barely tens of kilometres from each other. Conditions vary from extremely wet on the West Coast of the South Island to almost semi-arid in Central Otago and subtropical in Northland.

Most areas of New Zealand have between 600 and 1600 mm of rainfall, spread throughout the year with a dry period during the summer. Over the northern and central areas of New Zealand more rainfall falls in winter than in summer, whereas for much of the southern part of New Zealand, winter is the season of least rainfall.

Mean annual temperatures range from 10°C in the south to 16°C in the north of New Zealand. Extremes are –22oc to 42oc. The coldest month is usually July and the warmest month is usually January or February. In New Zealand generally there are relatively small variations between summer and winter temperatures, although inland and to the east of the ranges the variation is greater (up to 14°C). Temperatures also drop about 0.7°C for every 100 m of altitude. Temperature range Summer

Summer: December – February. Average daytime temperature: 20 – 25˚C (68 – 77˚F)

Autumn: March – May. Average daytime temperature: 17 – 21˚C (62 – 70˚F)

Winter: June – August. Average daytime temperature: 12 – 16˚C (53 – 61˚F)

Spring: September – November. Average daytime temperature: 16 – 19˚C (61 – 66˚F)

Sunshine hours are relatively high in areas that are sheltered from the west and most of New Zealand would have at least 2000 hours annually. The midday summer solar radiation index (UVI) is often very high in most places and can be extreme in northern New Zealand and in mountainous areas. Autumn and spring UVI values can be high in most areas.

Most snow in New Zealand falls in the mountain areas. Snow rarely falls in the coastal areas of the North Island and west of the South Island, although the east and south of the South Island may experience some snow in winter. Frosts can occur anywhere in New Zealand and usually form on cold nights with clear skies and little wind.

2021 Highlights

Make NO assumptions – Please ask and discuss.

The purpose of this stage of work is simply to prove the techniques and obtain a nationwide building consent (MultiProof).

Exact installation details and specifications will be added later.

For example – Not required at this stage:

  • Wiring diagrams
  • Interior fitout
  • Lighting diagram.

Required:

  • Solar schematic with technical details
  • Wastewater processing schematic with technical details
  • Window design (Graham)
  • Fire suppression schematic and locations
  • Structural calculations and specification
  • Kitchen – Placeholder sink, Hob, Oven
  • Bathroom detail – Placeholder sink and shower
  • Laundry sink and washing machine – Placeholder

MultiProof Permit

MultiProof is a statement by the Ministry of Business, Innovation and Employment (MBIE) that a set of plans and specifications for a building complies with the Building Code.

To be eligible you must have the intention and the ability to build an approved design at least 10 times over two years.

MultiProof speeds up the consenting process. It does not give the right to carry out building work that requires a building consent. You still need to apply for consent each time you want to build.

How MultiProof works

MultiProof establishes that a design complies with NZ Building Code.

When your building consent application includes a MultiProof the BCA must grant or refuse it within 10 working days instead of the usual 20.

The Building Consent Authority (BCA) confirms and establishes:

  • the design, with any permitted variations, is the same as the design approved in the MultiProof
  • the proposed site meets the conditions of the MultiProof
  • the site-specific features of the design comply with the Building Code
  • the inspections required.

There are certain documents, plans and specifications you will need to submit when you make your MultiProof application.

Download the MultiProof application form, together with the Compliance assessment report. You can have a look at Compliance assessment report example to see what type of information we expect from you.

Refer to making an application to find more information about the MultiProof application process, as well as other documents, plans and evidence you will need to provide.

Supporting Documents

Your MultiProof application documentation may differ from how you would usually put together a site specific design.

You should consider how to document your design in order to:

  • provide the level of flexibility you require
  • enable the design to be efficiently assessed
  • make it easier for your clients and BCAs to understand the alternatives.

Building Plans and Specifications

The drawings and specifications you submit as part of your MultiProof application should:

  • describe the intended construction of the building
  • demonstrate how compliance with the relevant performance requirements of the Building Code is achieved
  • provide sufficient dimensions, detail and information to enable the builder to construct the building as intended
  • state if all or part of the building is to be prefabricated
  • define all design alternatives.

The specifications should complement the drawings. This means information on the drawings should not be repeated in the specifications, and vice versa.

A brief description on the drawings should be backed up in the specifications by:

  • a full description
  • statements relating to relevant reference documents
  • technical trade literature.

You can also include the proposed inspection procedures and request they be approved as part of the MultiProof.

What not to include:

You should not include the following in your application:

  • construction outside the scope of the application
  • contractual information
  • site specific information
  • references to ‘or equal/other approved equivalent’
  • general references to clauses within an AS/NZS standard or Acceptable Solution (the actual clause should be included)
  • details of work that is not required to be assessed for Building Code compliance (such as shop drawings or internal joinery details).

Components, Materials and Products

Your drawings and specifications should include details about components, materials and products.

This includes any product technical statements that are available from manufacturers or suppliers for critical building products or systems. Including this information tells us what items are to be used and how they comply with the relevant clauses of the Building Code.

Product technical statements gives you further information on this.

If you use multiple suppliers for products, such as plasterboard, you must also nominate the manufacturers’ brand names and provide full details of the materials you intend to use.

This means we can approve them as part of your MultiProof and you can simply choose from these options for each individual build.

Demonstrating Building Code Compliance

As part of your application, you will need to provide enough evidence to demonstrate that your design, when built, will result in a building that complies with the relevant performance requirements of the Building Code.

To do so, you will need to provide a compliance assessment report.

The compliance assessment report lists all the relevant Building Code clauses and summarises how compliance with each clause is achieved. View an example of a compliance assessment report.

To show compliance you may be able to:

  • follow Acceptable Solutions or Verification Methods to show compliance
  • reference building products or methods covered by product certification or supported by any other product assurance pathway
  • utilize alternative solutions

If you are proposing to use building methods, materials or products new to New Zealand and you are not able to follow one of the above pathways, you will need to provide additional supporting information.

If you plan to use a new and innovative building product, you need to provide test results of a recognised standard demonstrating the performance of the product for New Zealand conditions (such as wind and exposure zones).

You also need to provide other documentation such as installation details and maintenance requirements.

You will need to use an expert with the relevant technical expertise to:

  • provide an opinion on the test methods and results
  • explain how the different Standards relate to the Standards referenced in the Building Code
  • translate these to New Zealand conditions.

Example

You want to use a new window product in your design. The main Building Code clauses relevant to this are:

  • B1 Structure
  • B2 Durability
  • E2 External Moisture.

The main reference document is NZS 4211:2008 Specification for performance of windows.

For tests such as for deflection, air infiltration, water penetration and ultimate strength you need to provide separate results for the different sizes (or at least for the largest size) and types of windows you propose to use.

For durability you need to demonstrate that the frames (along with all the various elements: reveals, fixings, flashings, gaskets, glass etc.) comply with the performance requirements of Clause B2 for the various exposure zones. Refer also to Table 1 in Acceptable Solution B2/AS1 as a guide, and Verification Method B2/VM1 regarding testing and other methods.

Detail Drawings

You will also need to provide detailed drawings of the manufacturer’s installation requirements to provide compliance (such as fixings, flashings, seals etc.) for the different installation situations, along with additional details for any specific New Zealand installations.

These should include any critical dimensions that affect moisture ingress (such as for sealant to perform, to prevent capillary action, and for overlaps).

Maintenance

You may also need to provide product literature documenting any maintenance requirements that are essential to ensure that the product as installed will continue to meet the requirements of the Building Code.

Structural Design

You need to provide us with information about the adequacy of the structural system before we can approve your MultiProof application. This will include:

  • a design features report
  • evidence that the design intent described in the report is achieved.

The design features report tells us how you intend the structural design to work. The clearer it is, the easier it is for us to be confident about your design.

The Report Should Detail:

  • which elements are structural and which are non-structural
  • how loads are transferred to the foundations (for vertical and for lateral loads)
  • the design standards used
  • any design assumptions that have been made
  • loads (snow, wind and earthquake) the building has been designed for
  • assumptions or limitations that have been made about ground bearing capacity.

If your structural design is in accordance with a non-specific design standard cited in an Acceptable Solution then your report may only be a few paragraphs long.

For a one or two storey structure without unusual or special characteristics, your report should be no more than two pages long.

Providing Evidence

You need to provide evidence that the design intent you describe in the design features statement or report is achieved.

Where specific design has been undertaken, you may need to provide the following types of evidence:

  • structural design calculations
  • a product certificate (CodeMark)
  • information from testing (this needs to be thorough and complete)
  • supporting information such as manufacturer test data and literature for proprietary products or components
  • a statement by an appropriately qualified Certified Professional Engineer about the adequacy of the structural system. This statement must explicitly state the basis of design (for example it is linked directly to the design features report above). In this case, we would expect you to provide the design calculations or other information relied on by the engineer.

The evidence could cover:

  • all structural elements including but not limited to:
    • foundations (if included in the application)
    • floor members
    • wall, posts and columns
    • bracing elements
    • roof members
  • connections between all structural elements, including the connections to the foundations.

Plumbing and Drainage

For a MultiProof plumbing and drainage should start and finish at the face of the building.

You need to show the proposed plumbing system in the MultiProof application complies with New Zealand building code. Drainage is site specific and will be assessed as part of the building consent.

You need to provide the following information in your MultiProof:

  • Plumbing design – Use Standard: AS/NZS 3500.2 for the plumbing design.
  • Waste, soil and water supply pipes – Specify size, fall and type of material. Include the relevant New Zealand Standard: for example, PVC pipes to AS/NZS 1260. Also include tub/washing machine pipe arrangement and both water (hot and cold) supply and waste pipes.
  • Pipe insulation – Specify insulation to pipes for energy efficiency or if required for frost protection.
  • Hot water heater – Specify type and energy source of water heater: for example, electric instantaneous water heater complying with AS/NZS 60335.1 and AS/NZS 60335.2.21.
  • Hot Water Cylinder (HWC) –Detail drains from temperature / pressure-relief (TPR) valve and water regulating valve (such as terminate over gully) and detail or specify seismic restraint.

Specified Systems

A number of buildings contain safety and essential systems to make sure they are safe and healthy for members of the public to enter, occupy or work in.

Certain systems are known as ‘specified systems’ and require a compliance schedule (under the Building Act).

Examples of specified systems include:

  • automatic systems for fire suppression (such as a sprinkler systems)
  • automatic or manual emergency warning systems for fire or other dangers.

If your building design involves any specified systems, you must also include the following information with your application:

  • a list and description of all the specified systems
  • the performance standards for each of the specified systems
  • and a description of the inspection, maintenance and reporting procedures.

This requirement does not apply to buildings used wholly as a single household unit except where a cable car is attached to it or servicing it.

Compliance schedules can explain this further.

Design Alternatives

You need to include all alternatives you are likely to use in each individual build in your MultiProof application.

If the alternatives are covered by your MultiProof you will have the flexibility to:

  • cater for local conditions such as differing exposure, wind or earthquake zones
  • make changes once the building consent has been issued.

To help you decide what design alternatives to include in your MultiProof application, think about the common modifications your clients request.

You must include alternatives that you consider minor. If you don’t, the BCA will assess the design as it does for any building consent application and may require that you provide additional supporting information.

The BCA’s normal 20 working day time limit will then apply.

Using MultiProof has more information about applying for a building consent with the statement.

Examples of design alternatives include, but are not limited to:

  • material alternatives
  • different cladding types
  • changes to window and door locations or configurations
  • variations to the floor plan (such as adding a garage or a conservatory)
  • handed (mirrored) floor plans
  • different bathroom and kitchen layouts
  • options for heating or hot water
  • changes in roof pitch (such as for roof pitches between x and y degrees)
  • building dimensions (for example, sheds using a standard roof design, or to allow a living area to be increased)
  • options for different wind and earthquake zones (such as bracing up to a certain level)
  • options for different exposure zones
  • foundation options for different soil capacity and site levels (for example, either with no foundations included or with a foundation option for good ground)
  • options for different climate zones (such as differing insulation levels)
  • options for add-ons such as garages, decks and conservatories.

If a range of alternatives are proposed you will need to provide a design and options summary, along with an index of the plans and specifications.

These documents will make it easier for the BCA to check which of the alternatives is proposed and which documents need to be submitted with the building consent application.

This summary and the index can also be included in the public register to provide information for potential customers.

If you find you don’t have the flexibility you require, you can also apply for an amendment to your MultiProof.

Waivers or Modifications

Section 30F(2)(a) of the Building Act also allows for waivers or modifications of the Building Code to be granted as part of the MultiProof.

If you are seeking a waiver or modification you need to identify this in your application and provide a separate written request which incorporates supporting material.

The following framework will be used as a methodology for deciding if it is reasonable to grant a modification:

  • The extent and possible consequence of the non-compliance with the specific performance clause.
  • The availability of other reasonably practicable solutions that would result in the building work fully complying with the Building Code and associated costs.
  • Any special and unique circumstances of the building work subject to the waiver or modification.
  • The extent to which the modification will still be consistent with the purposes and principles of the Act.
  • The modification complying with the relevant objective and functional requirements of the specific clause of the Building Code.

Housing Density

This understanding is consistent with the definition of Household unit in the A2 clause of the regulations and clause A1 2.0.2 detached dwellings which allows also for up to 6 boarders. The occupants intend to live under a single management arrangement and the owner determines those arrangements for the whole detached dwelling. 

Structural Engineer

Certified Professional Engineer

Abstel Glyde 0800 888 508

Background Info and NZ Applicable Information

Location: New Zealand. Seismic (Earthquake) rating required. Building is 15m x 15m square, monopitch roof is 3m at the west, 4m at the east (3 and 4 Kingspan panels high). To suit maximum roof panel length that can be transported, 15-16m roof panel. Steel post structural framing for ease of construction. Lounge windows will be north facing (Southern hemisphere), Garage in south east corner is about 5m wide with 3m door height, Entry is east facing in the centre of the 4m high wall, bedrooms west facing (3m high wall). Kitchen on north west corner. House may have 1 or 2 garages side by side (So structure is identical, just replace one section of wall panels with a garage door).

Tasks

  • Structural Post framing on concrete piers. This carries the cladding load as well.
  • Horizontally laid Kingspan exterior cladding affixed to above steel frame
  • Monopitch roofing – 15m (approx.) x 1m sections laid from low wall to high wall. Direct fixed to trusses with 3M type flexible structural adhesive or Liquid Nails Fuze It Max or similar to provide diaphragm bracing
  • 15m span (North to South) truss design – Cheapest design for self-assembly on site. C-section steel metalcraftgroup.co.nz/products/purlins-girts-tophats/products/mc-purlin-and-girt

metalcraftgroup.co.nz/products/purlins-girts-tophats/products/mss-purlin-and-girt
Possibly ply clad for visuals/strength. Could also be 100% wooden (Staggered joint layered construction ply).

  • Seismic calculations
  • Linear actuators for the garage door – Calculate pivot points for the load (See image from firgelliauto.com)
  • Supply results to Architect for inclusion in the plan
  • Optional Mezzanine supports with stressed skin panel floor design 4.8m wide, 10-15m long. 18mm top ply, 12mm underside screwed and glued (perpendicular to top grain) with Resorcinol Formaldehyde glue to 95mm x 45mm pine at 4.8m length and 400mm centres, screws at 150mm centres. (I have used this combination before).

References:

NZ Building code is called NZ3604 (Preferable standard). Australian standards are generally acceptable directly (Australia does not have earthquakes for example and NZ does not have termites). International Building Code (IBC) has to be ‘Considered as a viable solution’. British Standards and ISO are likely to be acceptable.

While the use of trusses is covered under NZS 3604:2011 Timber-framed buildings, there are a number of design limitations applied. (30 July 2015) In summary, these are:

  • the truss must be specifically designed in accordance with B1/VM1 and manufactured by an accredited fabricator
  • a maximum truss span of 12 m
  • a maximum truss spacing of 900 mm for a heavy roof and 1200 mm for a light roof
  • the load on the ends of the trusses to be no more than 16 kN in both directions – up and down
  • a maximum snow load of 2 kPa.

Find Acceptable Solutions, Verification Methods, updates and technical guidance by Building Code clause

120 building standards for free download

NZS 3604 Timber-framed buildings

Wind zones and NZS 3604

Building Code Handbook

Compliance Schedule Handbook

Handbook Amendments

branz.co.nz/calculators-tools H1 Calculation method, H1 Schedule, H1 Hub, Artisan Building Inspection app, Bracing calculation sheets, P21, Lintels and Beams

P21 A wall bracing test and evaluation procedure (2010)

TR10 Supplement to P21: An evaluation method of P21 test results for use with NZS 3604:1990 (1991)

Current P21 bracing test and evaluation procedure

Supplement to P21: an evaluation method of P21 test results for use with NZS 3604:1990, TR10 (1991)

AS1720.1-1997 and Eurocode 5 (European Committee for Standardisation, 1995)

Bracing using NZS 3604:2011 – part 1

Bracing for a timber-framed building is required to resist horizontal wind and earthquake forces. The bracing demand to resist wind is expressed in bracing units (B/Us) per lineal metre and bracing units per square metre for earthquakes.

Before starting bracing calculations, the designer will need to collect the following information for the specific building.

NZS 3604:2011

Is the building being considered within the scope of NZS 3604:2011? For this, it must be no more than 2-storeys and a maximum height of 10 m from the lowest ground level to the uppermost portion of the roof.

Designs within the scope of NZS 3604:2011 must provide bracing capacity that exceeds the higher of the minimum requirements in NZS 3604:2011 for:

  • wind demand – Tables 5.5, 5.6 and 5.7
  • earthquake demand – Tables 5.8, 5.9 and 5.10.

Wind zone

Some territorial authorities have maps with wind zones. Otherwise, see NZS 3604:2011 5.2.1 to work out the wind zone. Steps to do this are also in Build 128 February/March 2012, pages 24–25, or consult an engineer.

When the structure is situated in a lee zone, also see the increased requirements in the notes at the bottom of Table 5.4.

Earthquake zone

Establish the earthquake zone from NZS 3604:2011 Figure 5.4. For Christchurch, refer to Building Code clause B1 3.1.2.

Floor plan area

What is the floor plan area in square metres at the level being considered? This is needed for earthquake demand calculations – the total floor area of the level being considered is multiplied by the values given in Tables 5.8, 5.9 and 5.10.

 Figure 1: How to work out H and h.

Figure 2: Bracing for wind along the ridge.

Figure 3: Bracing for wind across the ridge.

Weight of claddings

Wall claddings are separated into:

  • light wall cladding – has a mass up to 30 kg/m2, for example, weatherboards
  • medium wall cladding – has a mass over 30 kg/m2 and up to 80 kg/m2, for example, stucco
  • heavy wall cladding – has a mass over 80 kg/m2 and up to 220 kg/m2, for example, clay and concrete veneers (bricks).

Roofs are either:

  • light roof – has roofing material (and sarking where required) with a mass up to 20 kg/m2 of roof area, for example, profiled metal roofing
  • heavy roof – has roofing material (and sarking where required) with a mass over 20 kg/m2 and up to 60 kg/m2 of roof area, for example, concrete or clay tiles, slates.

Site subsoil class for earthquake calculations

Site subsoils are classified in NZS 3604:2011 C5.3.3 as:

  • class A – strong rock
  • class B – rock
  • class C – shallow soil sites
  • class D – deep or soft sites
  • class E – very soft soil sites.

Territorial authorities often have maps with the soil classifications. If this information is not available, site subsoil classification class E must be used or specific engineering design carried out.

The type of soil class is needed to calculate the bracing units required to resist earthquakes. For multiplication factors for soil types see:

  • Table 5.8 – single storey on subfloor framing for various wall and roof claddings
  • Table 5.9 – 2-storey on subfloor framing for various wall and roof claddings
  • Table 5.10 – single and 2-storey on slab for various wall and roof claddings.

Building shape

What is the building shape? NZS 3604:2011 clause 5.1.5 sets out the requirements for buildings that have:

  • wings or blocks that extend more than 6 m from the building – these need sufficient bracing individually
  • split-level floors – each level to have sufficient bracing individually and to have wall and subfloor bracing at the position of the discontinuity
  • floors or ceilings with a step more than 100 mm in the finished levels – a bracing line is required in the storey below at the location of the discontinuity, and the bracing element in the storey below must run continuously from the storey below to the underside of the upper levels.

Figure 4: Dimensions for mono-pitched roofs.

Heights of buildings

Use NZS 3604:2011 Figure 5.3 to establish heights H and h for bracing applications. H may have different values for different sections of the same building (see Figure 1), for example:

  • for subfloor bracing requirements, H = the average height of finished ground level to the roof apex (use Table 5.5)
  • for a single or upper floor level, H = single or upper finished floor level to roof apex (use Table 5.6)
  • for lower finished floor level, H = lower finished floor level to roof apex (use Table 5.7)
  • for roof height above the eaves, h = apex of roof to bottom of eaves (use Table 5.5, 5.6 and 5.7).

Roof types

What is the type(s) of roof? NZS 3604:2011 Figure 5.3 shows where bracing needs to be in relation in wind direction.

GABLE ROOF – WIND ALONG RIDGE

Bracing elements to resist wind are placed in line with the ridge and wind direction (see Figure 2).

To calculate the required bracing units along the building, multiply W by the value in the right-hand ‘Along’ column in NZS 3604:2011 Table 5.5 (subfloor), 5.6 (upper or single-level walls) or 5.7 (lower of 2 storeys). These tables are for high wind zone. In other zones, use the multiplying factor for the relevant wind zone found at the bottom of the relevant table.

GABLE ROOF – WIND ACROSS RIDGE

Bracing elements for wind across the building are positioned in line with the wind direction and at right angles to the ridge line (see Figure 3).

To calculate the bracing units required in the across direction, multiply L by the value in the ‘Across’ column in NZS 3604:2011 Table 5.5 (subfloor), 5.6 (upper or single level walls) or 5.7 (lower of 2 storeys). As above, if not in a high wind zone use the relevant wind zone multiplying factor at the bottom of the table.

HIP ROOFS

Use ‘Across’ values in NZS 3604:2011 Tables 5.5, 5.6 and 5.7 for along and across directions.

MONO-PITCHED ROOFS

Roof height above the eaves is taken as the difference between lower eaves height and roof apex (see Figure 4).

When roof pitch is:

  • 25° or less, use wall width or length
  • greater than 25°, use roof dimensions.

To calculate the bracing units required, use the higher value of the along and across calculations in NZS 3604:2011 Tables 5.5, 5.6 and 5.7 is used.

Limitations on bracing allocation

Based on hold-down capabilities, there are some maximum ratings for bracing elements that can be used in calculations. The maximum for:

  • timber floors is 120 bracing units/metre
  • concrete floors is 150 bracing units/metre.

The bracing design should evenly distribute the bracing throughout the building rather than concentrating them in ends of buildings or outside walls.

Extra B/Us for part storey and chimneys

Where there is a part storey contained in a:

  • timber-framed basement, regard the building as two buildings for demand calculations — one 2-storey (has basement underneath) and one single-storey – and use the appropriate tables
  • roof space, the bracing demand values in Tables 5.8, 5.9 and 5.10 (earthquake) must be increased by 4 bracing units/square metre.

Where a masonry or concrete chimney is dependent on the building structure for lateral support, additional demand is also required – see B1/AS3.

Braced wall layouts and diaphragms

By Roger Shelton – 1 April 2015, Build 147

Braced wall layouts and structural diaphragms are the focus of a steady stream of enquiries at BRANZ. This is a tricky area, so it’s crucial to understand the concepts and what’s important.

BRACING LINES are imaginary lines running along or across the full length or width of a timber-framed building. They have no physical significance but are required to control the positioning of bracing elements.

Laying out bracing lines

There are a few rules for the layout of bracing lines to ensure good seismic performance:

● They must run in two orthogonal directions, generally aligned to match the wall layout – NZS 3604:2011 Timber-framed buildings says they must be parallel to the external walls.

● They should be as evenly spaced as practical. Generally, use more bracing lines rather than fewer, as this makes the distribution rules easier to apply.

● Where two walls are parallel to one another and:

• up to 2 m apart, consider placing a single bracing line between them – bracing elements in both walls contribute to the total of the line

• more than 2 m apart, insert an extra bracing line – the number of brace elements required won’t be affected as there is no change to the demand, and which wall or line they go in is merely a matter of convenience.

● Timber-framed floor and ceiling construction with standard or typical detailing can transfer lateral loads between bracing lines spaced up to 6 m, or 7.5 m with dragon ties (NZS 3604:2011). A structural diaphragm is required for spacings wider than this.

● Bracing elements can be located anywhere within the bracing line. This is helpful with door openings or an open room space. A continuous top plate can distribute the demand within reason.

Examples help explain the concept

By understanding the bracing line concept, designers have more freedom with room sizes.

In Figure 1, the large hatched room appears to require a structural ceiling diaphragm because of its size. However, there is a suitable arrangement of bracing lines across and along the building. Provided the distribution rules of NZS 3604:2011 are followed and enough bracing elements are located in each wall, this plan will be adequately braced. Note that the top plates of walls containing bracing elements must be continuous to the external walls (clause 8.7.3.4 of NZS 3604:2011).

Figure 1 Several bracing lines go through the large hatched room.

Figure 2 shows another situation often asked about. The exterior portion of wall on bracing line B has a large door and can’t provide the required external wall demand of 15 × length within its own length. However, this requirement can be placed anywhere on the bracing line. The shaded interior portion of the wall would comply provided the top plate is continuous to the external walls.

Figure 2 Bracing may be located on bracing line in internal wall.

Although clause 5.4.3 of NZS 3604:2011 states that bracing elements shall be located as close as possible to external corners, this is often prevented by the location of walls suitable for bracing. While this is the ideal, the intent of this clause is attained provided top plate continuity is achieved. Again, the distribution rules of NZS 3604:2011 must be complied with.

Diaphragm transfers bracing loads

Timber-framed buildings in New Zealand are constructed as ‘platform framing’, which means we build one level at a time. We take the same approach with bracing design, considering each level separately, with no requirement to align bracing walls in each level (clause 5.4.3).

When bracing elements in different storeys don’t line up, a load path is required to transfer the bracing loads from the upper level down to the lower level bracing. This load path may be a floor or a normal flat plasterboard ceiling acting as a diaphragm.

A diaphragm is a horizontal (or near horizontal) bracing element that transfers forces between vertical bracing elements. The diaphragm does not count in the bracing design for either level but is needed to connect the two levels together.

Structural diaphragm if >6 m apart

When bracing lines are spaced more than 6 m apart, a specially detailed structural diaphragm is required, according to NZS 3604:2011.

Diaphragms must be continuous

To function correctly, a structural diaphragm must be continuous over its whole area.

If the ceiling in the large room (Figure 1) was at a higher level than the rest of the building, specific engineering design would be required because of the loss of continuity.

Steps in floors are a break in this continuity. NZS 3604:2011 requires that steps greater than 100 mm are effectively treated as separate diaphragms, with a bracing wall required below the discontinuity (clause 5.1.5).

Bends in ceilings (for example, ridges, hips, valleys, coved ceilings) are another type of discontinuity. NZS 3604:2011 doesn’t provide any guidance or details in this area, so BRANZ recommends that these are not used for diaphragms.

Technical literature that provides continuity details at folds and edges of ceiling diaphragms should be used rather than the provisions of NZS 3604:2011.

Upstairs Floor Construction

75×50 at 400mm centres with 15mm ply on top and 12mm on bottom. Resorcinol formaldehyde glued, clamped with screws. Will do 4m span. (45mm does 3.6m span)

Architect

Archicad v25+ Metric measurements

Background Info and NZ Applicable Information

Approx. 15m x 15m with 3m wall on west side to 4m wall on east side. Monopitch roof spanning from 3m to 4m walls with no eaves but edge diverters to channel the rainwater to the gutter rather than allowing it to run off the edges. Lounge and dining rooms on North facing side (Southern hemisphere). Kitchen on North-West corner, Bedrooms on West side. Garage entry on South East corner.

No ceilings – just dropped ornamental panels suspended from trusses (No rafters, just trusses). Internal walls to underside of roof level in bedrooms, bathrooms, laundry and kitchen, otherwise airspace above suspended ceiling panels open to underside of roof. External cladding is laid horizontally – Corners are 45o v-cut and folded sections of wall panel (Size TBA by Structural Engineer).

Tasks

  • Take Structural Engineer’s information and construct framing, cladding, roofing model. Rebated roof panel over top of wall panel. External 90o flashing and internal 90o steel angle screwed or riveted to both panels (Steel or stainless rivets only – Aluminium NOT to be used owing to galvanic interaction between dissimilar metals).
  • Add truss design detail from Structural Engineer
  • Add ring wall foundation detail
  • Structural glazing / window detail
  • Flooring system and insulation detail from Structural Engineer and Thermal Modeler
  • Wastewater detail – Use Australian Earthsafe Polymer Twin Tank system
  • Rainwater collection from roof
  • Ventilation detail from HVAC Engineer
  • Add basic internal walls to ceiling level, airspace above suspended ceiling panels @2.7m height (Ventilation etc. above) 3 bedrooms, internal garage, 2 ensuites, laundry, kitchen (Rest is open plan). Suspended fake ceilings in living area. Bedrooms – Negative detail on dropped ceiling to ensure airflow (Depends on HVAC advice).
  • Plan BIM
  • Design BIM
  • Build BIM
  • Handover BIM
  • Kingspan details (Corners, Base, Roof/Wall joint, front end of roof, gutter and roof intersection
  • Window design – Include detail sketch
  • Design façade system based on galvanized steel square section to roof height with various claddings. Frame to be approximately 100mm from exterior of Kingspan with cladding returned to flush with Kingspan exterior. Consider bracing issues. See ‘Yellow frame’ image below (Could be C section steel).
  • Model façade options (Framing on one layer in Archicad, cladding options on independent layers)
  • Optional Conservatory basic design for the 20m x 25m house. Mezzanine guest suite above office.

References:

Wastewater Engineer

Background Info and NZ Applicable Information

All wastewater exits directly through the West wall from toilets, sinks, showers, laundry, into an above ground, single pipe, main sewer line that heads to the treatment facility positioned at the Southwest corner of the house. Vanities exit through an ‘S trap’ underneath the sink, then behind the wall directly into the sewer line. Showers, laundry and kitchen floors drain to a recessed gutter drain set into the floor inside the dwelling then out to external ‘P type trap’. Drain to extend across width of room to allow for floor washing water flowing into the drain.

Roof collected water is pre-filtered and treated before being stored in a 25,000 litre tank. Nine litres per minute in the shower and six litres per minute from taps are the recommended flow rates. If boosted pressure is needed: waterpumpsnow.com.au/rm4000-4-rain-to-mains-system-w-rm1600-2-4-sizes-detail or pumpstore.co.nz/tle900a-household-pressure-mains-booster-pump-90lmin-p-627.html.

Clean water piping is also external to the building and enters at point of use. Buteline pipe in New Zealand is extruded from premium grade Polybutene-1 (PB-1), is a non-hybrid material specifically developed for use with hot and cold potable water. Threaded plastic rod through wall with nut each side, fittings on each end (i.e. Do not thread Buteline through a hole). Brass Plumbing Pipe cannot be used on systems carrying potable water.

Clean water from the tank flows to the LifeStraw ‘Community’ water filter to provide potable water. Other water usage is direct from tank to laundry, sinks, showers and toilets.

IoT using Zigbee or Z-Wave to monitor wastewater quality, levels in rainwater, septic. Possibly use the SepticSitter.

Tasks

Validate, design and create specification and certification for regulators for:

  • Septic system (YouTube design)
  • Rainwater harvesting treatment method prior to storage
  • Potable water (LifeStraw)
  • Discharge water quality monitoring, specification and maintenance schedule
  • Supply results to Architect for inclusion in the plan.

References:

ID Compression fittings for connecting septic system tanks to each other to increase ease of flow. Earthquake resilience – Polyethylene Pipeline Performance Against Earthquake or use reinforced rubber hose between each tank with Jubilee type clamps. Alternatively, install tanks on a platform and isolate the platform on rubber feet sitting on concrete pads set into ground.

Do NOT use G12 (hot and cold) or G13 Acceptable Solutions. Use:

  • AS/NZS 3500.1.2015 for cold water
  • AS/NZS 3500.2.2015 for foul water
  • AS/NZS 3500.4.2015 for hot water.

Further, the applicant will need to specify which foul water system is being used, with 5 general categories being offered; fully vented; fully vented modified; single stack, single stack modified or drainage principles. The plans will need to reflect this system, and the plumber or drainlayer will need to apply for an amendment (prior to starting work) if they wish to change the system. Minor alterations can still be dealt with by a variation on site.

MultiProof – Plumbing and Drainage Requirements

For a MultiProof, plumbing and drainage should start and finish at the face of the building.

You need to show the proposed plumbing system in the MultiProof application complies with New Zealand building code. Drainage is site specific and will be assessed as part of the building consent. (INCLUDE Drainage as this is ‘Off-Grid’ and waste is processed onsite).

You need to provide the following information in your MultiProof:

  • Plumbing design – Use Standard: AS/NZS 3500.2 for the plumbing design.
  • Waste, soil and water supply pipes – Specify size, fall and type of material. Include the relevant New Zealand Standard: for example, PVC pipes to AS/NZS 1260. Also include tub/washing machine pipe arrangement and both water (hot and cold) supply and waste pipes.
  • Pipe insulation – Specify insulation to pipes for energy efficiency or if required for frost protection.
  • Hot water heater – Specify type and energy source of water heater: for example, electric instantaneous water heater complying with AS/NZS 60335.1 and AS/NZS 60335.2.21.
  • Hot Water Cylinder (HWC) –Detail drains from temperature / pressure-relief (TPR) valve and water regulating valve (such as terminate over gully) and detail or specify seismic restraint.

Basic Design

IBC 1000 Litre DN50 Outlet Reconditioned (Used, non-toxic grade)

Aim for potable quality discharge from system (Reverse osmosis and UV treatment – Can this be shared with rainwater harvesting?

Rainwater collection from roof – Treat before storing in tanks, Rainwater tank – 30,000l (Need 2 for whole property). Lifestraw to convert tank water to potable.

UV Water filtration

Viqua VH410 Ultraviolet system (Canadian, NZ approved)

Treat water from rainwater storage with LifeStraw for potable water.

Bidets in all bathrooms

Plastic Pipe Through Wall Fittings

Thermal Modeler

Background Info and NZ Applicable Information

Aim is to have zero heating requirement. No sunroom being used with the smaller house (Approx. 15m x 15m with 3 to 4m monopitch roof). Walls to ceiling level, airspace above suspended ceiling panels in bedrooms for extraction, bathrooms, laundry and kitchen. Lounge, dining and garage have no ceiling – open to underside of roof. Sunroom / Conservatory is a possible solution to creating usable outdoor space and free heating. Lounge windows will be north facing (Southern hemisphere), Garage south facing, Entry east facing, bedrooms west facing.

Underfloor to have 300mm EPS at edges (Inside ring beam) then 38mm XPS across the rest.

Doors will be ‘Cool store’ quality air sealed and insulated (R4 approx.)

Windows will be R1.69 (Centre of pane) in the daylight hours with R1.97 shutters closed at night (Approx. R3.66 total at night).

Tasks

  • Calculate heat loss of Walls, Roof, Windows and Floor
  • Validate design and specification of floor insulation – International best is the target
  • Calculate winter and summer heating and cooling loads
  • Advise on overheating mitigation (Sunroom?)
  • Supply results to Architect for inclusion in the plan and BIM
  • Optional Sunroom performance assessment.

References:

Directory of Simulation Software and Tools

HTflux is an innovative software to for two-dimensional simulation of heat and water vapor transport. GLASER 2d, a unique method developed by HTflux applies the well-known and proven Glaser method on two-dimensional geometries. This enables you to calculate dew point zones including condensation and evaporation amounts for two dimensional configurations. In addition, HTflux tries to make your life as easy as possible: an easy-to-use interface, smart import of CAD geometries and the method of DIRECT MAPPING enable you to create accurate simulations in the shortest possible time. 30 day trial software

IES Energy Modeling Software Building energy modeling predicts building energy consumption, CO2 emissions, peak demands, energy cost and renewable energy production.

Whole building energy simulation analysis capabilities of the IESVE software tools covers a wide range of assessment types from energy efficiency, comfort, ventilation, HVAC performance and optimization. Design for the future with low impact energy systems and strategies. Trial available

EnergyPlus™ is a whole building energy simulation program that engineers, architects, and researchers use to model both energy consumption—for heating, cooling, ventilation, lighting and plug and process loads—and water use in buildings. FREE

How to prepare the BIM model for the Energy Evaluation

Integrated in the ARCHICAD environment, Energy Evaluation offers an easy-to-use workflow for performing dynamic building energy calculations on projects of any size.

Using the same dynamic building energy simulation technology as the standard compliant EcoDesigner STAR for ARCHICAD add-on, Energy Evaluation is an energy evaluation tool that enables architects to monitor and control all architectural design parameters that influence building energy performance. The Energy Evaluation tool performs reliable dynamic energy evaluation at all stages of the design process, so that architects can make informed decisions regarding their buildings’ energy efficiency. Including Energy Evaluation in the architectural design workflow makes it easy to create projects that conform to or even exceed energy efficiency regulations and comply with building energy standards.

  • Create and visualize multiple thermal block Building Energy Model (BEM) geometry directly from the ARCHICAD BIM using the Energy Model Review Palette.
  • Use the Model-Based Solar Study to determine the intensity of solar irradiation on each external glazed opening individually, on every hour of the reference year – including the shading effect of the surroundings (buildings, plants etc.) and shading devices.
  • Export the ARCHICAD model geometry and material property data via IFC or as an XLS spreadsheet, to be processed by external energy analysis applications
  • Run the dynamic energy simulation, using the VIP Core engine that is integrated in ARCHICAD, to produce an Energy Performance Report. This report provides information on the project’s yearly energy consumption, carbon footprint and monthly energy balance.

Free Energy Modeling Software

  • eQUEST
  • OpenStudio
  • Simergy
  • Energy3D

listoffreeware.com/free-energy-modeling-software-windows

Honeybee creates, runs, and visualizes daylight simulations using Radiance and energy models using OpenStudio and EnergyPlus.

Fluid Dynamics Modelling

AKL FlowDesigner Works with Archicad

OpenFOAM is the leading free, open source software for computational fluid dynamics (CFD)

Flowsquare

Walls

Kingspan QuadCore AWP Wall Panel. R 7.15, U-value (W/ m2) 0.14 for 140mm thick 14.8 Kg/ m2 (AU). Core thickness 200mm = 0.069 U-value (R=12.3)

Roof

Options:

Kingspan QuadCore KS1000RW insulated roof panel. Core thickness 100mm = 0.19 U-value (R=5.35)

MetecnoPanel is a lightweight sandwich panel with a built in PIR fire resistant core. 100,mm, 150mm, 200mm. 200mm approx. R10+

Windows

Edgetech Super Spacer Warm Edge Spacer Bars 40-year performance guarantee. 6.5 m K/W (Best). Thermal Conductivity 0.15 R1.13.

12-14mm is optimum gap. Thicker glass makes little difference

3M All Season Window Film R0.44

Triple glazed (including warm edge spacer, thermal break, 3M film) = R1.69

Triple glazed (including warm edge spacer, thermal break, 3M film both sides) = R2.13 (Centre of pane)

Edge of pane R3.21. 2 layers might reduce the light transmission too much. Also, not needed in the daytime and shutters make it unnecessary at might.

Internal shutters add R2.97 for 95mm Expol Platinum (60mm + 35mm plus 2x 3mm mdf) (36mm total thickness for triple glazing and 3M window film) Total = R1.69 + R2.97 = R4.66

Not worth it:

  • Double glazed (including warm edge spacer, thermal break) = R0.8
  • Double glazed (including warm edge spacer, thermal break, 3M film) = R1.24
  • Triple glazed (including warm edge spacer, thermal break) = R1.25
  • Secondary glazing adds R0.19
  • Curtains add R0.26
  • Low E adds R0.16
  • Argon adds R0.17

Window Sizes:

  • Kitchen 2m wide x 1m high @ 1m above floor level
  • Bathroom Laundry 1m x 1m high @ 1m above floor level
  • Bedrooms 2m wide x 1m high @ 1m above floor level
  • Lounge 2m wide x 2m high @ floor level

Floor Insulation

10% of building heat loss is through the floor. 80% of this is through the edges rather than evenly due to lack of sun warming and night cooling effects.

USA R measurements are 5.68 times larger than those expressed in metric (SI) units due to Imperial v Metric units.

Use PVA or Aliphatic glue to:

  • Polystyrene joints
  • Kopine to polystyrene
  • Kopine joints.

Maximum U-value of 0.13W/m2K for the floor (UK) R7.7

Soil conductivities can range from as low as 0.5W/m °C for very dry soil R=2.0, through 1.2W/m °C for average soil, to as high as 2.0W/m °C for wet soil. R=0.8 for average soil. Roadbase will be encased in waterproof membrane to maintain 7% moisture, prevent drying out and water ingress.

Expol Platinum Board delivers an R-value of R 0.77/25mm

XPS: ezisteel.co.nz/products/thermal-break

Kopine R0.17 m2K/W (R=1)

R7.7 for: dry soil, (R2), Particleboard (R1) and 150mm Expol Platinum (R4.69). $16k extra

R6 for: dry soil, (R2), Particleboard (R1) and 65mm Expol Platinum (R3). Total heat loss (0.284W/K): 284

R5.3 for: dry soil, (R2), Particleboard (R1) and 50mm Expol Platinum (R2.29). Total heat loss (0.295W/K): 295

R4.58 for: dry soil (R2), Particleboard (R1) and 35mm Expol Platinum (R1.58). Total heat loss (0.307W/K): 307

Kw/day – 2 hours in morning, 6 in evening. 9 hours @30c/kW = $2.70 per day. Heatpump would reduce to 60c

5000BTU/hr (0.4 ton, 1.4kW) sensiblehouse.org/nrg_heatloss.htm = $1.15/day

Solar Power Design Engineer

Background Info and NZ Applicable Information

Aim is to create a multi house power system as cost effectively as possible. Electricity in NZ is $0.28NZD per kW, so cost is a major driver in viability. One HWC element is wired directly to PV panels (48v required) and the other (220v) to the inverter for topup. PV panel array and control room / battery room outside. 220v runs direct to each house fusebox. Load sharing with 2 inverters (In case one breaks down). IoT using Zigbee to monitor each house and performance, load.

Tasks

$97.20USD 31 units per pallet = 18kW – Therefore, 2 pallets (2 spares) = 156m2

  • Inverter choice – 2 off Solis 20kW Three Phase Solar Inverter 4G, Dual MPPT With DC Switch and WiFi dongle.
  • Battery choice. Sealed Lead Acid (SLA) of the Absorbent Glass Mat (AGM) type. NOT gel type batteries. High-quality AGM batteries can be discharged to 80% of their capacity over hundreds of cycles, and typically last 4 to 7 years in a home energy storage setup. 50~60% maximum depth of discharge for SLA batteries is recommended for maximum battery life. Will replace with saline batteries when these expire.
    Century Yuasa is a good brand. >10 year lifespan possible
    36kW/h – so inverter needs 30x 12v batteries 1,000Ah = $4000 x 2 days = $8000
    Century Deep Cycle Battery – 27DCMF 96Ah 12v Cold Cranking Amps: 680CCA
    supercheapauto.co.nz/p/century-century-deep-cycle-battery—27dcmf-96ah/522756.html?cgid=SCN01060103#start=2
  • Battery Management. Battery conditioning technology – Wavetech
  • Hot water Cylinder – 3kW of panels wired direct to 48v HWC element. Is holding tank necessary for summer? Heat water to maximum temperature (70-80oc) and temper the water at exit to 60 oc (45 oc at basin taps). DC Twin Core Hot Water Element. 12v, 24v, 48v powerspout.com/products/dc-twin-core-hot-water-element?variant=4968610496549 or plumbingplus.co.nz/products/rheem-420l-solar-storage-with-electric-boost
  • Wiring diagram. Isolation switches for panels, battery, HWC and inverters to allow safe maintenance
  • Disposal of solar gain in summer, Switch off panels or dump into swimming pool (How many litres)?
  • 8kW diesel generator – Auto failover for house. Mainly for workshop and spa (Direct wired to generator). Rubber feet, vertical exhaust muffler (or vent through water). Diesel is cheaper per hour and motor should last longer. Noise levels: 70db is ‘Quiet’, 80db is usual. Preference is to get to <60db using noise baffles etc.
  • Complete report required. Supply only RELEVANT excerpts to Architect for inclusion in the architectural plan. This will be ‘Conceptual’ elements for a Building Consent.

Alternative (Single supplier, cost comparable):

References:

Fire Engineer

Background Info and NZ Applicable Information

Occupants likely to be elderly, disabled or include children. Automated fire suppression rather than fire extinguishers.

Tasks

  • Analyse risk areas – Kitchen, Solar inverter (In outside shed), Fusebox (In house), Bathrooms, Laundry, HWC are main areas but all living areas require smoke detectors, so one Maus Xtin per room as a minimum.
  • Advise on location of suppression devices:
  • Maus Stixx Pro
  • Maus Xtin Klein – Class B and C
  • Supply results to Architect for inclusion in the plan.

QuadCore KS1000RW Roof Panel

QuadCore AWP Wall Panel

BS 8414 tested solution that has passed the requirements of BR 135 and complying with BS EN ISO 9001

Kopine 20mm particleboard floor over 35mm polystyrene insulation.

Triple glazed, non-opening windows.

Mechanical ventilation to living areas, direct to outside extractor fans in wet areas and rangehood in kitchen.

References:

MultiProof – Specified Systems Requirements

A number of buildings contain safety and essential systems to make sure they are safe and healthy for members of the public to enter, occupy or work in.

Certain systems are known as ‘specified systems’ and require a compliance schedule (under the Building Act).

Examples of specified systems include:

  • automatic systems for fire suppression (such as a sprinkler systems)
  • automatic or manual emergency warning systems for fire or other dangers.

If your building design involves any specified systems, you must also include the following information with your application:

  • a list and description of all the specified systems
  • the performance standards for each of the specified systems
  • and a description of the inspection, maintenance and reporting procedures.

This requirement does not apply to buildings used wholly as a single household unit except where a cable car is attached to it or servicing it.

Compliance schedules can explain this further.

HVAC Engineer

Background Info and NZ Applicable Information

Given the large internal air volume, lack of sealed rooms, the idea is to exchange air to the outside during the warmest part of the day and rely on internal air volume to dilute the CO2 at night within the house. Direct extraction to outside at point of generation for wet, humid and cooking air. Bedrooms (Sealed) would use air to air transfer fans during the night to swap air with lounge. Garage needs to self-manage exhaust emissions when vehicle enters or leaves. All windows are non-opening and airtight. Doors are airtight. IoT using Zigbee to monitor CO2, CO, NO2 levels etc.

NZ calculation methods are simplistic and are not designed for airtight, semi passive, ventilated house designs. Best to use ‘First principles’ proof.

The average adult needs 420 to 480 liters per hour when resting. (0.48 m3/h or 7-8l/s)

The Building Code requirement for fresh outdoor air ventilation requires ventilation for occupied spaces in accordance with NZS 4303:1990 Ventilation for acceptable indoor air quality.

Occupant loading = 2 (Master BR) +1 (BR 1) +1 (BR 2) = 4 people.

Rangehood of >100cfm

Bathroom shower extraction direct from above shower to outside via 200cfm axial fan suspended in ceiling space with downward sloping straight pipe to exterior (To allow for natural draining of condensation or residual water over time).

No dryer in laundry (Outside washing line under cover).

Suspend all axial fan motors on polythene string from rafters to minimise noise and vibration.

Tasks

  • Timed ventilation in all applications
  • Kitchen ventilation and extraction
  • Main house ventilation to outside
  • Shower ventilation (Use diffuse photoelectric sensors to trigger timer)
  • Adequacy of ventilation in sealed rooms like bedroom
  • HEPA filtration
  • Garage ventilation. Transfer type fans – inflow and outflow on different walls. Set on 30-minute timer after car arrives/leaves (Use inductive detection sensor to trigger)
  • Supply results to Architect for inclusion in the plan
  • Optional Sunroom/Conservatory

References:

Kitchen Ventilation

Externally vented, suspended motor to reduce noise. Rangehood with 100L/s extraction rate

tradedepot.co.nz/master-kitchen-integrated-rangehood-520mm-stainless-steel

eboss.co.nz/library/parex/paradigma-white-ceiling-rangehood-silent

Bathrooms and Laundry

Wet rooms and Kitchen have humidity triggered MHRV. As close as possible to source (Above shower). Humidity sensitive ventilation systems (Lunos Nexxt or aereco.com/ventilation/humidity-sensitive-ventilation) automatically adjust the airflow depending on the room humidity, without electricity. It still regarded as a major technological breakthrough in demand-controlled ventilation. Filtration hard to implement on MEV. No ducting required on MEV. Intelligent air inlets, make the MEV B more efficient than the MEV A.

Mechanical extract fans (including associated ducting) must have a flow rate not less than:

  • 25 L/s for showers and baths, and
  • 50 L/s for cooktops.

Aim for double. Suspend fan motors on polythene string from rafters to minimise noise and vibration. Downward slope for ducting to allow moisture to exit the building naturally.

Lunos Nexxt

Nexxt is controlled via humidity or temperature sensors as a standard and optionally also via a CO2 sensor

  • Volume Flow   15 – 110 m3/h
  • Voltage            230V / 50 Hz
  • Power Consumption   5W @ 15m3/h
  • Heat Recovery           Up to 90%
  • Sound Power Level    20dB up to 30m3/h
  • Clean air using standard M5 filters with the option to increase to M7 or M9 for bacteria filtration
  • USB port for firmware updating, allowing to add wireless sensors, motion detectors and switches
  • Capability to connect to WiFi e.g. via smartphone application control
  • Intelligent automatic sensing of humidity and temperature as standard

Extractor fan above, on timer >50cfm

AeroFresh 60 for bathrooms

Evolve SV04E2 Home Vent with tablet for monitoring

Australian NATHERS 7-star rating is 137 MJ/m2, 10 star is 1 MJ/m2

CO2 concentration <600ppm

The Building Code (Clause G4) requires 5 percent of the floor area in opening devices or mechanical ventilation to achieve an air change in the occupied spaces (such as living areas) every three hours.

  • Outdoor air supply shall be designed and equipment installed to comply with NZS 4303, or AS 1668.2 (excluding Table A1
  • Where provided to remove moisture and other contaminants from kitchens, bathrooms, toilet spaces and laundries in household units, exhaust the air to the outside at flow rates given in AS 1668.2, Table B1 (flowrate not less than 50 L/s)
  • Building interiors ventilated by mechanical systems incorporating filtration shall, except where Paragraph 1.4.4 applies, be maintained at a positive pressure.
  • Remove exhaust air from the room mechanically at one third the inlet rate.

BRANZ recommendations:

Should be built to an airtightness target of 0.35 ach @50 Pa and, preferably, should have mechanical ventilation as the default option. NZS 4303:1990.

Check filters every 3 months, change every year. F7 filters, except the kitchen extract (in the room extract point): Typically, a dust & grease filter of G3 grade is being used. Use grade 8 (One below HEPA) to decrease load on fan significantly whilst producing almost the same quality of filtration.

ISO 16890, where the classification of filters is based on the method of filtration determined by giving the particle size as the particulate matter it can filter and its efficiency as a percentage. (G4 class filters were the industry’s standards and complied with the now outdated EN 779 standard).

Ecowindows supplied a German heat recovery ventilation system. 60% cheaper than Zehnder. Distributed MHRV with ceramic heat exchangers. Set to run only during times when area is used. No air filtering possible.

youtube.com/watch?v=mtxc7D8clxE

Smart system that reacts to changes in air quality

broan-nutone.com/en-us/overture-hardware-detail

Extractor fans 25 L/s AS 1668.2:2002