Reading through:

http://www.energysavingtrust.org.uk/Publications2/Housing-professionals/Refurbishment/Sheffield-EcoTerrace-A-refurbishment-case-study

one comes across:

“Although full details of the improvements to the Sheffield
EcoTerrace are contained in section 7 of this case study,
the implications of using a non SAP Appendix Q tested
technology should be considered. In this case, it would
have meant a drop of five SAP rating points (down to 87)
and one EPC band (down to band B). Additionally, the
dwelling’s CO2 emissions would have increased by about
0.3 tonnes per year.”

I can understand how having a non-tested MVHR system could affect the SAP and EPC ratings but not how lack of paper-work can increase emissions by 300 kg. After all, most of the “paperwork” is in reality probably electronic so causing emissions rather than sequestering carbon. And anyway, I doubt the paperwork involved contains the 81 kg of carbon needing to be sequestered to prevent that much CO₂ emissions.

Yes, I am being deliberately silly. But still it annoys me when people muddle up the “scores” the bureaucrats give them with what effect they're actually having in the real world.

Just felt like venting a bit of irritation, that's all.

The SAP software allows the Assessor to select SAP Q systems from the database, SAP2009 or 'User defined'.

I just checked the latter, manually entering the data for SFP and thermal efficiency - it gives the same answer. However, it does state that a datasheet must be available, presumably in the event of audit. I take this to be a manufacturer's datasheet, not a SAP Q report.

If the SAP2009 default is used, then performance is WORSE than natural ventilation plus fans. Complete nonsense.