Tuesday, 17 August 2010

PHPP and planning

We are still in planning, having revised our design in July to reflect the planners' concerns. The new design is currently out to 21 days' consultation (ending 25 August). The change meant we had to go through most of the data we had entered into the PHPP, as well as re-visiting some of the airtightness and thermal bridge detailing, to make sure that we could still meet the Passivhaus standard.

During that process, I discovered I'd made a silly but easy-to-make error in how I had entered data into the PHPP. I hadn't assigned all the areas I had defined to the correct building elements. Luckily, this error was in our favour. After I'd corrected the PHPP, our annual heat load figure dropped considerably so that we should be within the 15kWh/m2.a without having to include any particularly expensive options. It has taught me a lesson about how to minimise the risk of a similar mistake in future. It really is worth calculating the treated floor area separately and entering the total figure into the PHPP. It makes it easier to spot errors of the type I made.

I hope that we will have some good news about the planning soon, so that we can start on the build as soon as possible. Watch this space!