1. Introduction
When we don’t like or agree with something within our building regulations, it’s always the “bloody Building Code” that gets the blame.
In our fight to build better, so that every New Zealander has a home that is fit for purpose; warm, dry, well ventilated, resilient and durable, places where people thrive, it’s important to start with firm foundations.
This includes properly understanding and talking about the documentation that makes up our building legislation.
Let’s try and understand what a builder might mean when they refer to the ‘Building Code’.Let’s try and understand what a Chief Executive Officer might mean when they refer to the ‘Building Code’.
Because the average person in the building industry, let alone on the street, has absolutely no idea.
Let’s try and improve our collective understanding.
2. Our Current Legislation
The Building Control framework is explained in the diagram below. It is headed by the Building Act, which was last amended in 2004.
Fig 1. The Building Control Framework – a picture is as good as a thousand words.
2.1. Building Act 2004
The Building Act (2004) provides the mandatory framework for the building control system to be followed when undertaking building work in New Zealand. Its stated purpose is covered in section 3 of the Act:
(a) to provide for the regulation of building work, to ensure that:
(i) people who use buildings can do so safely and without endangering their health;
(ii) buildings have attributes that contribute appropriately to the health, physical independence and well-being of the people who use them;
(iii) people can escape from the building if it is on fire; and (iv) buildings are designed, constructed and able to be used in ways that promote sustainable development:
(b) to promote the accountability of owners, designers, builders and building consent authorities who have responsibilities for ensuring that building work complies with the building code.
2.2.Building Regulations 1992
Building Regulations are made under and in accordance with the Building Act. The Building Regulations include the Building Code.
2.3. Building Code
The New Zealand Building Code is contained in Schedule 1 of the Building Regulations 1992 which sets performance standards all new buildings must meet under the following headings;
General Provisions
Stability; B1 Structure, B2 Durability.
Protection from Fire; C1 Objectives, C2 Prevention of fire occurring, C3 Fire affecting areas beyond source, C4 Movement to a place of safety, C5 Access and safety for firefighting operations, C6 Structural Stability.
Access; D1 Access Routes; D1 Access Routes, D2 Mechanical Installations for access.
Moisture; E1 Surface water, E2 External moisture, E3 internal moisture.
Safety of Users; F1 Hazardous agents on site, F2 Hazardous building materials, F3 Hazardous substances and processes, F4 Safety from falling, F5 Construction and demolition hazards, F6 Visibility in escape routes, F7 Warning systems, F8 Signs, F9 Restricted access to residential pools.
Services and Facilities; G1 Personal hygiene, G2 Laundering, G3 Food preparation and prevention of contamination, G4 Ventilation, G5 Interior environment, G7 Airborne and impact sound, G7 Natural light, G8 Artificial light, G8 Electricity, G10 Piped services, G11 Gas as an energy source, G12 Water supplies, G13 Foul water, G14 Industrial liquid waste, G15 Solid waste.
Energy Efficiency; H1 Energy Efficiency.
The Building Code does not prescribe how work should be done, but states how completed building work and its parts must perform.
The Building Code consists of two preliminary clauses and 37 technical clauses. Each technical clause has three levels that describe the requirements for the clause and is listed below.
1. Objective: Social objectives the building must achieve.
2. Functional Requirement: Functions the building must perform to meet the Objective.
3. Performance: The performance criteria the building must achieve. By meeting the performance criteria, the Objective and Functional Requirement can be achieved.
3. Compliance Pathways
Compliance with the Building Code can be demonstrated using various pathways. Understanding the New Zealand building control framework helps understand which path is most suitable when designing and constructing building work, or explaining the part of the building control framework they are referring to.
The top three tiers of the pyramid above (the Building Act and Building Regulations) show mandatory building legislation that must be followed.
The rest of the diagram shows various paths that may be used to demonstrate compliance with the Building Code. Compliance with the Building Code must be demonstrated using one or more of the paths. The applicant can choose which path(s) to follow.
MBIE regularly updates the Building Code compliance pathways, building regulations, acceptable solutions, verification methods, guidance and information. You often hear about this via consultation documents.
3.1. Acceptable Solutions and Verification Methods
Acceptable Solutions are simple step-by-step instructions that show one way to comply with the Building Code.
Verification Methods are tests or calculation methods that prescribe one way to comply with the Building Code.
Acceptable Solutions and Verification Methods provide details for construction that, if followed, result in compliance with the Building Code. They are published by the Ministry of Business, Innovation and Employment.
A design that complies with an Acceptable Solution or Verification Method must be accepted by a building consent authority as complying with the Building Code.
There is at least one Acceptable Solution or Verification Method for compliance with each of the Building Code clauses.
For example the Acceptable Solution for Energy Efficiency is H1/AS1. The Verification Method is H1/VM1
Not every Building Code clause has an acceptable solution. Ideally, it should, but this is not the case.
For example H1.3.3 states
Account must be taken of physical conditions likely to affect energy performance of buildings, including –
(a) the thermal mass of building elements; and
(b) the building orientation and shape; and
(c) the airtightness of the building envelope; and
(d) the heat gains from services, processes and occupants; and
(e) the local climate; and
(f) heat gains from solar radiation.
There is currently no Acceptable Solution or Verification Method for airtightness or heat gains from solar radiation (overheating).
3.2. Other Compliance Pathways
These are pathways that are less talked about, used and understood. However, if followed they must be accepted as establishing performance requirements with the Building Code.
NZS 4121; the code of practice for design for access and use of buildings by persons with disabilities (and any modification of that Standard), is to be taken as an Acceptable Solution
Determinations; A determination is a binding decision made by the Department. It provides a way of solving disputes or answering questions relating to the Building Code and territorial authority/building consent authority/regional authority decisions under the Building Act.
Product certification; The Building Act contains provisions for a voluntary product certification schemethat will enable product manufacturers to have their products certified as meeting nominated Performance requirements of the Building Code.
Energy Work certificate; Energy work is defined as gas fitting work or prescribed electrical work. An energy work certificate certifies that energy work complies with either the Electricity Act 1992 or the Gas Act 1992.
3.3. Alternative Solutions
An Alternative Solution is a building solution that differs, in part or wholly, from the solutions offered by the Acceptable Solution or Verification Method, but achieves compliance with the performance requirements of the Building Code to the satisfaction of the building consent authority.
Whatever the reason for using an alternative solution, the Building Code, being performance based, allows for innovation and applicants have the freedom to propose an innovative solution. Refer to 2.3 ‘The New Zealand Building Code’.
4. Correcting terminology
Now we’ve piled some foundations on which to sit our building under the roof of the Building Act, we can grab a cuppa or a beer and discuss what we mean when we blame the bloody “Building Code”.
In nearly all situations, the real culprit is an Acceptable Solution (or lack thereof)
Builders often refer to NZS3604:2011 Timber framed buildings as the “Code”. It isn’t. 3604 is an acceptable solution. Just one way of complying with the objective, functional and performance requirements of the Building Code.
A chief executive recently said there was no provision in the Building Code for overheating.
BRANZ recently said the Building Code does not have a performance requirement to manage overheating in buildings.
Both are incorrect. As shown above, H1.3.3 covers the performance requirement. What is missing is an acceptable solution or verification method that provides simple step-by-step instructions that show one way to comply with the Building Code.
The big discussion point where the Building Code lets all New Zealanders down is G5.3.1
G5.3.1. Habitable spaces, bathrooms and recreation rooms shall have provision for maintaining the internal temperature at no less than 16°C measured at 750 mm above floor level, while the space is adequately ventilated.
The limit on this application is Performance G5.3.1 shall apply only to old people’s homes and early childhood centres.
But that’s an article for another day.
5. Conclusions and recommendations
Those of us who are commentating on our building control framework need to ensure we correctly understand what part of the framework we are talking about and use the correct terminology.
There is so much misunderstanding, misinformation and ignorance out there already. We don’t need to add to it.
Those of us providing education as part of our service, or day to day lives, must employ the correct terminology if we are to educate the industry and the public of New Zealand, as well as seen to be credible amongst our peers.
This is vitally important if we are to hold governments to account for the vision MBIE put forward in August 2020 in their document Transforming Operational Efficiency;
Our vision is by 2035, New Zealand’s new buildings are using as little energy and water as possible. They are warmer, drier and better ventilated, and provide a healthier place for us all to work and live. The wellbeing of New Zealanders has improved, they’re leading healthier lives, and respiratory illnesses from cold and damp houses are uncommon. People also have more money in their pockets due to lower energy bills.
The Building and Construction Sector can confidently and successfully design and construct energy and water-efficient buildings with low operational carbon emissions. Energy efficiency, water use and operational carbon emissions are core considerations for the Sector and new buildings now meet an emissions cap as well as other regulatory requirements.
Our infrastructure finds it easier to respond to demand for water, due to our lower use. This means we cope better with water shortages than we ever have before.
The efficiencies from the Sector have made it easier for the grid to become more renewable meaning fewer emissions for the energy we do use.
As a result, carbon emissions from building operations will have been significantly reduced compared with 2020 levels, and are making an important contribution to New Zealand’s trajectory towards achieving net zero carbon emissions by 2050.
HEALTHY HOME COOPERATION
Healthy Homes for all Kiwis. Housing is about people. People working together in cooperation to provide Healthy Homes for people to live in.
Damien McGill: Engineering Happy Healthy Homes for People & Planet
