The Passivhaus Institute is finally to announce a long trailed standard for refurbishments. This new standard, to be known as EnerPHit, will be easier to achieve. The headline targets are:
25kWh/m2.a - annual heat demand
1.0 - air changes per hour - airtightness standard
There'll be more detail on what assumptions lie behind these standards in the coming weeks I hope. Refurbishments to near Passivhaus standard will now be recognised with this new standard. The less stringent standard will make Passivhaus thinking and methodology more accessible to those refurbishing by giving them a challenging but achievable standard to aim for. I imagine that the procedure to gain EnerPHit certification will be similar to that for the full Passivhaus standard. Certification adds value by enforcing a certain discipline to the design and build process. This benefit will now to open to the refurb sector.
We will still be sticking with the full Passivhaus standard for our refurb. Being based in the south west of England has made it feasible to aim for. If our project had been located in Manchester, the colder climate there would make the full Passivhaus standard unrealistic practically and financially for us. The new EnerPHit standard would be within reach though.
Before we all relax too much, a quick comparison with other UK building standards reminds us that this new PH refurb standard is still far ahead of others; it will still be a huge challenge to get EnerPHit certification.