ALF 3.2 is a design tool for energy-efficient housing and has been updated to include the new insulation requirements in New Zealand Building Code Clause H1 Energy efficiency. It is still as easy to use as ever, but is now web-based and free. It is presented in a step-by-step format providing a simple method of calculating the energy performance of conventional New Zealand houses.
The web-based ALF 3.2 is an Alternative Solution for determining the Building Performance Index (BPI) and can be used to show compliance with Building Code Clause H1.
What ALF can do
The ALF calculation allows the user to:
- estimate the annual heating energy for a house design
- evaluate the effect on heating energy with increased insulation and different types of glazing and frames
- compare different building and window orientation
- compare options for retrofitting existing houses
- generate a report showing H1 compliance that is suitable for councils
- estimate building losses and indicate ‘weak’ areas of the thermal envelope.
It will also determine the usefulness of the thermal mass to heating energy requirements and describe how the building orientation will affect heating requirements.
ALF 3.2 can provide an understanding of how heating habits will affect heating requirements and consider the energy use implications in retrofit options for existing buildings.
Design tool for designers
ALF helps designers make decisions to ensure their houses are well designed, with low heat losses. In turn, this means the house will have lower condensation risks and higher indoor comfort levels and is healthier and cheaper to run.
ALF 3.2 can be found on the BRANZ website, www.branz.co.nz, under Toolbox.
Articles are correct at the time of publication but may have since become outdated.