Yes, at last, approval for the technical details of how the house will be built. However. like most things that aren’t run of the mill, this has been a bit of a challenge, and the explanation is potentially long and boring. In order to obtain a Building Warrant (the Scottish equivalent of the Building Regulations in England), a building has to conform to a certain standard of energy efficiency, called a SAP rating (Standard Assessment Procedure) laid down by the Building Research Establishment (BRE).
So far, so good, and one would imagine that a house that is extremely well insulated and airtight, where energy from the sun provides a significant proportion of the heating requirement, where the ventilation system recovers around 75% of the heat produced within the house by people and activities, and which therefore doesn’t need a primary source of heat would pass with flying colours. Well … think again. The current version of the SAP software designed in consultation with BRE, universally used to determine SAP ratings, doesn’t acknowledge that a house can be designed in this way. If a dwelling with no primary heat source (i.e. no gas or oil fired central heating, no ground or air source heat pump) is submitted, the SAP software defaults to assume that the house is heated by electric heating with NO controls, and the dwelling receives an automatic FAIL, meaning that it doesn’t conform to the energy efficiency standards required by Building Standards.
As I understand it, this problem applies to all dwellings currently designed to Passivhaus standards in the UK. The SAP standards, and the software needed to determine compliance is due to be revised soon, and rumour has it that this anomaly will be addressed in the new version. Can’t help thinking that it should have been sorted from the start – it’s hardly rocket science, as they say.
After much discussion, and submission of extra information from the Passivhaus analysis of the structure of the house, Dumfries and Galloway Building Standards have agreed to make a one-off exemption, and have issued the Building Warrant. It all makes me wonder why we Brits are so bad at building warm, airtight, comfortable houses that have very small fossil fuel requirements for heating. This type of construction has been around for at least 30 years in continental Europe, where winters are colder and summers are hotter than in the UK, but still we refuse to take up the proven technology and insist on inventing our own standards.
It’s probably the same mentality that caused us to vote to leave the EU; enough said.
Oh, and the snowdrops are flowering … hurray!