Mistakes in the UK’s Methodology for Calculating Residential Energy Consumption (SAP) makes each new home £500-£1000 more expensive to build.

Six errors have been identified in SAP and they are all to do with the way that it calculates
the energy saved from Waste Water Heat Recovery (WWHR) systems. With some at over
60% efficient, these systems are more cost effective to install than almost any other energy
saving product.
These issues will be explored further at a Press Conference on Thursday 3rd December.
Speakers will include Danny Kinahan, MP.
The fix is simple and would take less than two days to implement. Recommendations have
been taken to Lord Bourne, the Under Secretary State for Climate Change, but he will not
sign it off, claiming it to be Cabinet matter.
WWHR systems transfer the heat, usually thrown down the drain during showering, back
into the house by warming the incoming cold water feed. These systems are already used in
the UK, but not in the volumes found in other countries.
That something was suspicious about the UK’s SAP calculations first came to light when
WWHR was first used in the government funded AIMC4 project. WWHR was installed in a
number of homes and their measured performance was 1.4 to 2.7 times better than
calculated by SAP. These results were consistent with field measurements obtained
elsewhere in Europe and North America, where WWHR technology receives much more
credit in regulations and codes.
AIMC4 caused two competitors to join forces and carry out some research of their own:
“I am still amazed with the types of errors”, said Tony Gordon CEO of BPD the makers of the
Showersave Waster Water Heat Recovery product line, which is well known in Holland,
“some were really basic, even an algebraic error. These errors are just plain wrong, and
need to be fixed. “
“When all the errors were found we took the findings to civil servants in DECC who agreed
SAP should be changed,” said Gerald Van Decker, CEO of Power-Pipe Energy Systems. “They
worked with us, and highly regarded independent consultants to jointly come up with a
simple recommendation to Lord Bourne to undo the errors without having to change the
core of SAP itself. We know that Lord Bourne, to use his words, wants “more breathing
room for builders”, fixing these errors will provide just that, but he has refused to meet with
us to discuss how WWHR can help.”
House Builders have to make major changes as they try and make UK homes more energy
efficient. By not being given the full benefit of Waste Water Heat Recovery they will need to
install other measures which could cost them £0.8 – £2 billion by 2023.
About Building Products Distributors Ltd. (BDP)
Based in Northern Ireland, BPD co-owns Hei-Tech of The Netherlands. Hei-Tech is developer
and manufacturer of the Showersave technology. The Showersave is now installed in over
45,000 residences. .