BU661 Residential roofs with high thermal performance
This bulletin describes five highperformance residential roof details that give significantly better thermal performance than traditional construction.
BU660 Residential walls with high thermal performance
This bulletin describes five highperformance residential wall details that give significantly better thermal performance than traditional construction.
BU659 Upgrading the thermal performance of timber windows
This bulletin describes approaches for upgrading thermal performance including reducing air infiltration, replacing ordinary single glazing and retrofitting insulating glass units (IGUs).
(This bulletin updates and replaces Bulletin 507).
BU658 Timber Windows
Timber window installation is outside the scope of Acceptable Solution E2/ AS1, so building consent must be applied for as an alternative method
(This bulletin updates and replaces Bulletin 481).
BU657 Designing water-efficient houses
The primary concern for water supply design in a house will always be the health and safety of the occupants, but beyond that, there are opportunities to reduce consumption of reticulated water through efficient design.
BU656 Designing to avoid houses overheating
This bulletin gives an overview of passive design options for reducing overheating. It does not consider active (mechanical) ventilation systems.
BU655 Building blocks for new-build-net-zero carbon houses
Greenhouse gas emissions from new building work must be reduced for New Zealand to meet its commitment to a net-zero carbon economy.
This bulletin gives an overview of the decisions that designers, builders and clients can take to reduce the carbon footprints of new houses.
This is the second of two bulletins on net-zero carbon building. It follows Bulletin 651 Climate change, net-zero carbon and the building industry.
BU654 Installation and maintenance of solid fuel appliances
This bulletin outlines considerations for installation, use and maintenance of solid fuel appliances. Solid fuel-burning appliances can be free standing or built in. Terms used for built-in appliances include inbuilt heaters, fireplace heaters, inset or insert fires, slow combustion solid fuel stoves and solid fuel space heaters, which may be installed in an existing fireplace and/or chimney or in a new construction.
Solid fuel appliances, including flue pipes and chimneys, must be regularly cleaned and maintained.
This bulletin replaces Bulletin 306 Inspection procedures for chimneys, fireplaces and solid fuel burning appliances.
BU653 Damp-proof membranes to concrete slabs
Damp-proof membranes (DPMs) or concrete underlays are necessary under on-ground concrete floor slabs to prevent moisture from the ground passing through the slab and damaging the interior finishes, fittings and contents.
The use of a DPM is mandatory under slabs on ground for all habitable spaces and under slabs for garages or ancillary buildings that may be used as habitable spaces in the future.
This bulletin outlines the selection, design and installation requirements for DPMs. It updates and replaces Bulletin 469 of the same name.
BU652 Amendments to Acceptable Solutions and Verification Methods for B1 and E2
Acceptable Solutions and Verification Methods provide a means of demonstrating compliance with the relevant clauses of the New Zealand Building Code (NZBC). It is not mandatory to use Acceptable Solutions and Verification Methods, but if used, building consent authorities (BCAs) and territorial authorities must accept them as providing compliance.
This bulletin highlights some of the key changes to New Zealand Building Code Acceptable Solutions and Verification Methods for clauses B1 Structure and E2 External moisture that have come into effect since 2012. It highlights the amendments introduced in 2019.
This bulletin replaces Bulletin 545 Key changes to B1/AS1 and E2/AS1.
BU651 Climate change, net-zero carbon and the building industry
Recent calculations suggest that the built environment accounts for up to 20% of New Zealand's greenhouse gas emissions. Both new and existing buildings will need to produce fewer emissions to help meet net-zero carbon targets set in law.
This bulletin provides an introduction to the impacts of climate change and the move to a net-zero carbon economy on the New Zealand building industry.
BU650 Building beyond Code minimums
The New Zealand Building Code sets out performance criteria that all building work must comply with. Minimum requirements in the Code, in Acceptable Solutions and referenced standards cover areas from thermal insulation to ventilation levels.
Many new houses are constructed to just meet the minimum requirements of the New Zealand Building Code. Better-performing houses may cost more to build but are much more comfortable to live in and have reduced running costs to offset the upfront cost.
Our houses will need to perform considerably better to help meet long-term national net-zero carbon targets.
BU649 Corrosion of metals in New Zealand buildings
Corrosion is a chemical or electrochemical reaction between a material and aggressive substances in its surrounding environment. The interaction normally leads to the material being consumed and a reduction of performance, durability and/or visual attractiveness. A common example of corrosion is the rusting of steel, which converts the metal into compounds such as oxides, hydroxides or sulphides.
The economic cost of corrosion is enormous. One New Zealand estimate put it at the equivalent of 2.5% of gross domestic product (GDP) or around NZ$7.5 billion, while another put it at NZ$9 billion. International studies have estimated the annual cost of corrosion as the equivalent of 2-6% of GDP.
This bulletin gives an overview of the corrosion of metals in New Zealand buildings and explains how corrosion can be reduced and managed. BRANZ scientists have researched corrosion for over 40 years, and much of the content in this bulletin reflects their findings.
BU648 Timber shingle and shake roofing
Timber shingles and shakes have been used as a lightweight roof cladding in New Zealand for around 200 years. They are mentioned in current design guides for many heritage areas, but they are also found in contemporary styles of housing.
Shingles are sawn, have relatively smooth faces and usually have random widths and taper in thickness. Shakes are usually hand split (although some are also sawn) and usually have a rougher textured surface on at least one side. Widths are generally random.
Shingles and shakes are usually manufactured from residual timber left over from the main forest log production. They have a relatively small carbon footprint compared to some other roofing materials.
This bulletin outlines the selection, design and installation of timber shingle and shake roof cladding. It updates and replaces BRANZ Bulletin 443 Timber shingles and shakes.
BU647 Recessed downlights (luminaires)
LED technology has undergone significant changes in the past few years, making them an energy-efficient and cost-effective form of lighting as recessed luminaires. Retrofitting LED lamps into existing fittings can be done, but a better option may be to replace the luminaire.
This bulletin describes the classifications of recessed luminaires, their legislative and installation requirements and the range of lamps available. It replaces Bulletin 539 Recessed downlights.
This bulletin covers:
- recessed luminaire classifications
- installation requirements generally
- replacing lamps
BU646 Floor levelling compounds
Floor levelling compounds are used to correct minor imperfections and variations in strip and sheet flooring and concrete floors. This bulletin outlines the generic types of floor levelling compounds available, the substrates they can be applied to and guidance on preparing and applying them.
This bulletin updates and replaces BRANZ Bulletin 360 of the same name.
This bulletin covers:
- specifying floor levelling compounds
- product types
- compound application
- topping slabs.
BU645 Installing timber strip flooring over timber joists
Poorly installed timber strip flooring can result in problems such as cupping, warping, buckling and squeaking of boards. The main causes of problems are installing flooring before the building is fully enclosed, high moisture levels, boards of insufficient thickness and joists too far apart.
This bulletin describes the requirements for installing timber strip flooring over timber suspended floor framing and outlines finishing options and maintenance requirements. It replaces Bulletin 390 Laying timber strip flooring over timber joists.
This bulletin covers:
- subfloor framing
- timber flooring
- installing timber strip flooring
- floor finishes, cleaning and maintenance.
BU644 Solid timber strip flooring on a concrete slab
Solid timber strip flooring is a popular flooring for both domestic and commercial buildings. Traditionally, timber was installed over suspended timber subfloor framing but is now commonly specified as an overlay flooring over a concrete slab.
Poorly installed timber strip flooring can result in problems such as cupping, buckling and popping of boards. Common causes of problems include:
- the moisture content of the concrete slab being too high or insufficient moisture vapour barrier protection when the timber flooring is installed, resulting in moisture uptake and swelling of the timber
- the moisture content of the flooring timber not matching the moisture content of the internal space at the time of installation, resulting in expansion or contraction of the boards.
This bulletin replaces Bulletin 506 Laying solid timber strip flooring on concrete slabs.
BU643 Energy efficiency in New Zealand houses
BRANZ has carried out a House Condition Survey of New Zealand houses approximately every 5 years since 1994. The 2015 sample of 560 houses was broadly representative of the national housing stock and included both owner-occupied and rental houses. The survey comprised an on-site physical house assessment, a telephone interview with the occupants and an appliance use questionnaire completed by the occupants.
The survey found big opportunities for improving the energy efficiency in New Zealand houses. Improving energy efficiency has numerous benefits, from financial savings for households through to reduced greenhouse gas emissions.
This bulletin covers:
- space heating systems and appliances
- space heating habits
- thermal insulation
- water heating systems
- lighting and appliances
- residential electricity consumption
- regulatory changes around energy efficiency
- key opportunities for improvement.
BU642 Changes in the condition of New Zealand houses over 25 years
Before the first BRANZ House Condition Survey (HCS), there was no regularly collected, in-depth data on the state of our houses. As far back as 1935, the government had recognised the importance of house condition on New Zealanders' lives and acknowledged the need to collect information on it.
BRANZ set out to uncover the physical condition of a sample of randomly selected New Zealand houses, with trained assessors using objective criteria. The survey also allowed calculation of the level of maintenance and repairs required and estimated the cost of those repairs. The HCS provided an important new source of information for policy making. It has also helped BRANZ researchers to understand the performance of different building materials and to target further research.
- Current Page: 1