H1 Building Code Clause - Energy Efficiency
Changes to Building Code Clause H1 (Energy efficiency)
In August 2007, the Department of Building and Housing announced major changes to Clause H1 of the Building Code, which deals with energy efficiency. The changes include increased insulation requirements and an increased recognition of the appropriate use of thermal mass.
The amendment was put into place to create more energy efficient new homes and buildings and took effect on 30 September 2008.
What does this affect?
Careful consideration is required when specifying building materials. The new H1 requires higher thermal performance levels for most parts of the building envelope.
The H1 change affects all housing, communal residential, communal non-residential and commercial buildings. The changes also affect all extensions to these buildings.
The change does not affect industrial buildings or the industrial component of multi-use buildings.
Compliance methods
It is the designer's responsibility to provide relevant information and evidence to council to demonstrate compliance.
There are a number of compliance methods that can be used:
- the schedule method
- the calculation method
- the annual loss factor (ALF) method
- the modelling method.
Schedule method
Insulation R value specifications for the glazing, skylights, walls and ceilings together with the calculation of window to wall ratio (WWR) need to be submitted.
Calculation method
A copy of the calculations of the heat loss for the actual building and the heat loss for the reference building need to be submitted.
Annual loss factor (ALF) method
You need to provide the calculation of the Building Performance Index (BPI) to prove that the BPI of the proposed building does not exceed 1.55.
Modelling method
Approved computer software endorsed by the Department of Building and Housing or suitable authority shall be used to prove that the annual energy consumption of the proposed building is equal or less than the annual energy used by the reference building.
Summary
Presentation for Northland Area
These methods are demonstrated in the attached presentation which was delivered to the Far North District during October. For the Northland region it is not necessarily a requirement that double glazing will need to be fitted into new buildings. In general, if the building is of a “normal” standard, has 50% or less glazing in its construction, and uses the highest rating insulation materials in its envelope, double glazing should not normally be required. However, it is up to the applicant or builder to show compliance with the H1 building code using one of the above methods, and as such, each case is treated by council on a case by case basis.
Other Sources of Information.
DBH website - www.dbh.govt.nz - energy efficiency
DBH Website - Building Code Clause H1
Branz Wesite - www.branz.co.nz - ALF Calculations
Page created/updated: 18 December 2008 at 5:44 pm
