Occasionally I do a reply to a blog post with a blog post and this is one such occasion.
The response is following on from the post by Piers Taylor on Passivhaus: ‘Passivhaus – Is it the Future?’. The post is especially relevant as today’s Guardian has a full page on the concept and implementation of a Passivhaus approach – CLICK HERE FOR THE ONLINE VERSION
And as the faithful readers know that I’ve written copiously on the Passivhaus method, have completed the Passivhaus PHPP course and midway through the Certified Passivhaus Designer/Consultant course. So I guess I’m well on the way to being a Passivhaus ‘Zealot’ 😉
But that being said, I love a conversation and this blog post is exactly that, a response to the issues raised in Pier’s blog post:
I’ll start with explaining what the Passivhaus standard is about:
1. It’s the design and construction of ANY building (not just a house) that has a comfortable temperature for every room, day an night throughout the building for every day of the year with very low heating bills. A building needs to meet an exacting standard in terms of design and construction in order to meet this standard. You can get your building certified as a Passivhaus via an accredited Passivhaus certifier through the Passivhaus Institute.
The temperature for every room is designed, calculated and built to be 20 degC
It’s a common misconception that a Passivhaus requires no heating; this isn’t the case – for a largish, detached house the heating costs are in the region of hundreds of euro rather than thousands per year.
2. The house is designed and constructed to be very comfortable to live in; no condensation on windows (internally), no mould growth and ventilated with lovely clean air.
And that’s more or less it.
I’ve also written a blog post on Passivhaus fallacies HERE
Let’s look at the words in bold and if you ask ANY person, would you like a house that has very low heating bills and is very comfortable to live in you’d obviously say YES.
And that’s it, it’s just a bunch of physics, maths and construction methods that achieve these two things.
With the Passivhaus methodology you can design, model and test different designs, configurations and construction methods in order to EXACTLY determine whether you are meeting these two key goals before you build without any guesswork. The calculations are just another weapon in the architects armoury to help achieve a better building for your client.
The trick for architects is to use the physics/maths in a way that doesn’t compromise the delight of good design and I’ve already written my worries on this matter in my post on: A few observations on being a certified passive house designer and since I’ve written this post the situation has changed and the certification is split into Certified ‘Consultants’ and Certified ‘Designers’ (interestingly the exam is the same but to be a certified Designer you need to also give proof of design qualifications.
The gorgeous projects by Piers Taylor could have been designed to be Passivhaus projects, you as the architect have the choice to decide whether you want to meet the standard that meets the goals described and equally you have the choice not to. That’s what Passivhaus is giving you, a choice. The choice you make can determine EXACTLY what your heating bills will be for any particular month or for the whole year. Now you can choose to ignore the results and pay a little bit more for your heating or you can take the results on board and reduce your heating costs – I know which one I (and I guess most people) would choose if they could afford it. Equally you can also choose whether you have your project certified or not; currently in Germany some architects certify the first couple of houses but the ones after that (meeting the same standard) tend not to be certified Passivhaus’ – again you have the choice.
That’s it for this post, but I’ll need to continue it next week on my own experience and building my own house…