The Annual Loss Factor method is a design tool, which can help you to improve the thermal efficiency of houses. ALF can be used to optimise features such as insulation levels in walls, roofs or floors, to analyse the effects of double glazing, to investigate the importance of building and window orientation and to evaluate many other thermal design features. ALF can also be used to show compliance with the Energy Efficiency Clause of the New Zealand Building Code.

ALF is very simple to use. It requires very little time and the results are presented in several user-friendly formats, such as printable reports, charts and graphical displays of heat flows in and out of the building.

Click on the thumbnail image to view the enlarged ALF3 screen shot.

	The building description can be easily done on the six building design screens. The program uses a large number of pictures, which help the user to make design choices. Design variations can be easily implemented through single click building rotations, bulk construction material changes for all the walls, roofs or windows and other features.
	The graph screen shows heat losses and heat gains for each of the main building components, such as walls, windows, floors and roofs, as well as the contributions of internal gains and the energy required to warm up the building after it was let to cool down.
	The display screen shows the energy flows of two designs in pictorial form. Each project can contain up to 30 different designs that can be compared easily using the display screen.
	The economic analysis screen shows the results of a cost benefit analysis. The cost effectiveness of any two designs in a project can be compared against each other. ALF calculates the lifetime cost of different design options based on some very basic economic parameters, which can be specified by the user.
	The optimisation tool automatically calculates energy consumption and lifetime cost for a range of values. A large number of building characteristics, such as window sizes, R-values etc. can be optimised using this tool.
	The NZS 4218:1996 calculation screen shows the result of a compliance test of the current design against the Schedule Method of NZS 4218:1996. This is one of the three compliance methods with Clause H1 of the New Zealand Building Code, which ALF3 checks.
	The heater sizer is a simple tool that shows the user the approximate size of a heater required to heat a specific room.

The software minimises the need to reference other documents. The particular design requirements you favour for walls, roofs and windows can be defined and stored for routine inclusion in the software. Indeed most of the input files are in ASCII format so that you can modify and update input data easily.