Some councils like to go beyond national building regulations and have their own standard.  This might be 10% better than national building regulations in some areas or require 10% or 20% of energy to be generated by renewable means.

The  SAP assessor will start with a very basic design that just about passes the SAP test.  This is called the Baseline calculation.  This design is then improved as much as possible to produce a second calculation which contains several refinements but no solar panels (if these are the renewable means you want to install.)  The council don’t expect you to build a very poorly designed house and then try to solve the problem by putting a solar panel on top.  They expect to see evidence of real effort to get the best possible design.  The third calcualtion will include the solar panels (if these are used.)

The results may need to be presented using a website or a form provided by the council or it may be a long letter written according to a council policy document.  The report would normally include consideration of what would be the best systems to use in the building depending on its size and whether it is a house or an industrial building.  It may also include Code for Sustainable Homes issues like whether a home office, cycle sheds or clothes drying space could be provided.  The report will show the % reduction in CO2 due to improving the design beyond normal SAP requirements and the % reduction in CO2 due to the solar panels or renewables if these were used.

What is an Energy Sustainability Report?