Published by the Building Industry Authority (now the MBIS), these provide specific construction details which are deemed to comply with the Building Code and have to be accepted by Councils when considering applications for building consents
Alternative Solutions are construction designs and details that differ from the Acceptable Solution and need to be approved by the Councils before they can be used in a building.
Building Industry Authority (now part of MBIE) which administered the Building Act, and among other roles, issues and reviews Acceptable Solutions, warns against. or bans the use of particular products or building methods, publishes guidance information on the requirements of the Act, registers, trains, reviews, audits and revokes accreditation of building consent authorities (councils).
A timber preservative used to protect wood against borer and decay. The active ingredient not toxic to mammals in small amounts and not considered an environmental threat. Treatment of timber with boron was the recommended outcome of the boron equiry and has been the main treatment used in NZ since the early 1950's.
A government enquiry set up in 1952 to find a cost-effective treatment for protecting timber from borer and decay.
The Building Research Association of New Zealand is an independent government body, mainly funded from a levy on building consents, which researches building methods and materials for use in New Zealand. They are also paid by manufacturers to Appraise their products as fit for purpose and meeting the requirements of the Building Code. These Appraisals are heavily relied on by Councils, Specifiers and Builders .
A BRANZ Appraisal is supposed to be a robust, in-depth and independent evaluation of a building product or system certifying that it is fit for purpose and meets Building Code performance requirements. BRANZ Appraisals of leaky home products such as untreated timber, HI timber, Harditex, and Hardibacker allowed councils to approve their use in houses, Architects to specify them and Builders to buy them. HIstory has shown that these Appraisals were defective.
The old NZ timber treatment classification used for framing timer used until around 1986, which predated the H1 classification. Approximately twice the boron of the current H1.2 standard, C8 treated timber resisted borer and decay with occasional wetting. H1 continued to be made to the same level of boron treatment until 1992 where the treatment levels were allowed to reduce to a level where decay resistance was lost after a small amount of wetting.
A gap formed by a vertical batten in a wall that allows draining, and airflow for drying. This is normally between the framing and cladding to dry out any leaks, and minimise water ingress due to wind pressure. In many houses being built today however, the cavity is between the cladding and rigid air barrier board, leaving no mechanism for framing timber to dry.
The Territorial Authority, appointed by the BIA (now MBIE) normally responsible for issuing building consents, inspecting buildings, during construction and issuing Code of Compliance Certificates.
A binding decision by the MBIE (formerly the BIA) to solve a dispute or question about rules applying to building work, such as consents.
A monolithic cladding sheet product made from compressed wood fibre, sand and cement, for example, Harditex and Hardibacker. Fibre-cement is absorbent and moisture can soak through it, wetting timber away from an actual leak site.
A timber treatment standard used from around 1986 for insect protection only. Originally high effective at protecting against both borer and decay, H1 mirrored the old New Standard C8 timber treatment levels. H1 treatment levels were reduced in 1992, then changed again in 1996 where, because the timber only required treatment against insects, insecticides such as permethrin were permitted. This gave no decay protection.
A timber treatment standard for low decay hazard and termite protection however H2 was not permitted to be sold in New Zealand. H2 timber would have been far more resistant to decay than H1 and would have dramatically reduced the rot issues seen in leaky homes.
A timber treatment for timber subject to wetting, which normally uses CCA (Copper, Chrome, Arsenic). H3 is very effective treatment for both decay and borer. NZ Standard 3602 1995 required H3 behind absorbent cladding subject to solar-driven condensation. This description fits both Harditex and Hardibacker (stucco), however, this was either not understood by councils, or not enforced and undertreated H1 or untreated timber was used instead.
An absorbent fibre cement board manufactured by James Hardy, used as a rigid backing board behind solid plaster (stucco) on external walls. Usually installed without a cavity, this system is often associated with leaky homes.
The fibre cement board at the centre of the current Class Action Court Case. Sold from 1986 to 2004, many houses clad with this product subsequently suffered leaks and decay issues.
One of six environments of use where timber is at risk of degradation by insects, fungi or bacteria - classed as H1 to H6. H1 is essentially a dry protected environment.
An EIFS (polystryene) monolithic cladding system. Hitex responded to the early reports of leaky buildings with a vented cladding, then developed the cavity Diamond EIFS to ensure that any moisture from leaks could drain and dry out.
One the first EIFS (polystyrene) monolithic cladding systems that received BRANZ Appraisal in 1985, opening the door to a slew of other face fixed cladding systems with no drainage cavity.
Ministry of Business, Innovation and the Environment - currently responsible for administering the Building Act.. See BIA above.
A type of exterior wall cladding that has a uniform, seamless appearance. The main types are fibre cement board with a plaster texture (e.g. Harditex), solid plaster stucco (e.g. Hardibacker) and Externally Insulated Finishing System (polystyrene, e.g. Insulclad).
The Standard specifying the Minimum Requirements of the NZ Timber Preservation Council i.e. how timber has to be treated.
Code of Practice for Specifying Timber and Wood-Based Products for use in Buildings. This specifies what grade (treatment level) of timber has to be used in a building.
NZ Standard for Timber Framed Buildings. This specifies how buildings are to be designed and built.
The quantity of preservative retained in the wood after treatment
An EIFS (polystryene) monolithic cladding system
A group of relevant industry experts assembled to produce, update or amend New Zealand Standards.
Part of the Ministry of Business, Innovations and Employment (MBIE). Their role is to develop internationally aligned New Zealand Standards, which are the agreed specifications for products, processes, services and performance.
Treated with preservative to the relevant specifications
A marketing term used for Untreated Kiln Dried Timber (UTKD) which resists decay and insects when completely dry but is very vulnerable if it gets wet
A wood and bitumen based rigid backing board, which was direct fixed to the framing under solid plaster (stucco) exterior finished. This was highly absorbent so moisture from leaks was able to move through the Triple S and soak into unprotected timber.
Untreated Kiln Dried Timber resists decay and insects when completely dry but is very vulnerable if it gets wet. This was able to be used provided the moisture content did not exceed 18%. In practice, this was usually exceeded during construction (rain), and regularly exceeded once the house was built. With no moisture monitoring system (e.g. moisture detection probes), installed in a house, this could then decay.