Windows may be causing delays on site, but there is plenty of activity elsewhere in the Passivhaus world

Work on site has ground to a halt – for reasons I will go into below – but I have had a busy couple of weeks promoting Passivhaus design at various events.

The most taxing was an online webinar debate ‘Is Passivhaus right for the UK’ last Wednesday (part of Buidling's Sustainability Now online conference) - taxing mainly because the technology which makes it possible – amazing as it is – was a bit challenging for someone of my technological backwardness.

Nevertheless, it was a good experience overall and I particularly enjoyed the Gentoo presentation on their Sunderland social housing development. Our one-off house is relatively easy to organise, they have 28.

I am also just back from a one-day conference on Passivhaus schools, run by Passivhaus Buildings. It included two representatives from Frankfurt and Belgium who gave us many examples of Passivhaus schools in their respective regions.

Of course, it did make you wonder why we are so behind in this country, but despite that, there was a good feeling amongst the 120 delegates, many representing local authorities. Maybe the times are a-changing.

But information on Passivhaus is becoming more prevalent in the UK. The AECB: the sustainable building association is an extremely influential not-for-profit organisation, which is perhaps not as well known as it deserves to be.

Green Building Store Directors Chris Herring , Steve Slator and I have been members of the AECB since its inception in 1989 and Chris is currently its National Chair. The AECB has, amongst its membership, many of the UK’s leading practitioners in low energy building.

Tackling climate change is an urgent priority for the AECB and in 2008, funded by the Carbon Trust, the AECB launched the CarbonLite Programme, which draws on over 20 years of expertise of constructing low carbon buildings – both from within the AECB membership and from successful low energy programmes in Canada and Europe - especially the German Passivhaus movement.

The AECB CarbonLite Programme has been providing training courses throughout the UK on Passivhaus design for the last couple of years. Before we started on the Denby Dale Passivhaus both Chris Herring and I attended the very first ‘Introduction to PHPP’ course and Green Building Store’s Paul Smith is attending a comprehensive 5-day course on Passivhaus principles, PHPP and thermal modeling in London this week, so that we will be able to offer PHPP in-house.

PHPP input for the Denby Dale Passivhaus has been ably provided by AECB stalwart Peter Warm and his daughter Sally Johns. Throughout the design stage Pete and Sally have also been liaising with the Passivhaus Institut in Germany and checking details with them. Pete has since gone on to be trained as a Passivhaus certifier – attending a three week residency at the Passivhaus Insitut in Germany so that he can now certify Passivhaus buildings in the UK on behalf of the AECB.

Passivhaus certification of buildings in the UK, backed by the Passivhaus Institut, can now be offered by the AECB, BRE and SHS in Scotland. So far, to the best of my knowledge, there are only two certified Passivhaus buildings in the UK – both built by JW construction and both in Wales. The Denby Dale house will be one of the first certified by the AECB, and is likely to be within the first six in the UK. But watch this space – things are beginning to move fast in the Passivhaus world!

Another new initiative in the Passivhaus movement in the UK is a not-for-profit organisation Passivhaus Buildings. This has been established by the AECB to take forward and expand on the work of the CarbonLite Programme, and promote Passivhaus in the UK. Passivhaus Buildings will continue the training and educational work of the CarbonLite Programme, including web-based design guidance, training and events. .

On site

As with many building projects (or so it always seems on Grand Designs), we have been delayed by the windows yet again. We have the frames and the glass but at the last minute the clients have had a change of heart about the colour and so the frames are now being repainted from light grey to dark grey to match the soffits.

In some ways this has been good as it has allowed me to divert the building team to our own offices, where we’re converting part of our base at Heath House Mill into a display space and training room. The frames are being repainted as we speak and should be in before Christmas, fingers crossed.

At last I think we’ve come up with an answer to the problem of the cold bridge at the door thresholds rightly raised by John Carney in part three and also discussed in part four. We have commissioned a local workshop to mould a 100mm x 100mm fiberglass box section which we will fill with Polyfoam insulation.

We will need to cut back the concrete slab to accommodate the box, and mechanically fix into the edge of the slab with a resin grouted stainless steel threaded bar. The external step will probably be made of chequered galvanized steel plate for grip.

The door threshold

Door threshold