SAP Results - check everything

[Stratman]

I just got the design stage SAP report. Rather shocked at the predicted energy rating of C despite it being a build with high insulation, triple glazing, good airtightness , etc. So I read through the calculation worksheets to discover a load of errors. U values higher than the MBC thermal modelling that I sent them, MVHR completely ignored, generic oversized ASHP used, wrong building dimensions (like 30% greater floor areas and storey heights!).

 

Entering the correct ASHP alone has dramatically improved the results and I have insisted they redo the whole report using the information I provided.

 

Very poor effort. I suggest checking any report or calc you receive and don't be afraid to question and push back if it looks wrong to you. We pay good money for services like these.

[JohnMo]

2 minutes ago, Stratman said:

I just got the design stage SAP report. Rather shocked at the predicted energy rating of C despite it being a build with high insulation, triple glazing, good airtightness , etc. So I read through the calculation worksheets to discover a load of errors. U values higher than the MBC thermal modelling that I sent them, MVHR completely ignored, generic oversized ASHP used, wrong building dimensions (like 30% greater floor areas and storey heights!).

 

Entering the correct ASHP alone has dramatically improved the results and I have insisted they redo the whole report using the information I provided.

 

Very poor effort. I suggest checking any report or calc you receive and don't be afraid to question and push back if it looks wrong to you. We pay good money for services like these.

Yes - not really that important l on the design stage, but very important at the 'as build' stage, make sure all assumptions are correct as well as everything else. 

[Mr Punter]

Don't pay them until they get it right.

[Stratman]

19 minutes ago, JohnMo said:

not really that important l on the design stage

Not a deal breaker for building control, I agree, but if I provide ample accurate data, I expect them to use it. Also, to improve the result they suggested doubling up on PV which would have cost me unnecessarily.

[JohnMo]

14 minutes ago, Stratman said:

doubling up on PV

I would be doing that anyway - panel are £120 per kW plus mounts, so wouldn't you.

[ProDave]

2 hours ago, Mr Punter said:

Don't pay them until they get it right.

No, Don't pay them and find someone who actually understands it to do the job instead.