Our planning application has been filed. Thus I know the exact dimensions of the thermal envelope, plus all windows and doors.

I have quotes from two timber frame manufacturers with options for various U values and target airtightness. I have typical U values for triple glazed windows.

The house may or may not be to Passivhouse standard, we have yet to decide. However we will not go down the certification route.

 

What I need now is a first cut estimate of the energy demand of the house once completed. Right now I have no idea what the difference would be of a TF of U value 1.4, vs. say U 1.1 ?  Is it worth paying the extra?. What would the pay back period be? What size HP would be needed. Do I need A2W  and UFH, or would A2A be better ??

 

To get to grips with this I feel I need to get a spreadsheet together with all the calcs in so I can play around with the numbers.

 

To save me the effort of starting with a blank spreadsheet, does anyone know of a template and guidance to put something together?

 

I guess at some point I will need a professional SAP calc done, but I would like to progress a DIY approach for now.

 

Search here for Jeremy Harris' heat loss calculator. Not used it myself (Architect used PHPP) but people here say it's spot on.

Great, found it, this is exactly what I wanted.