Passivhaus at Ecobuild: separating the hits from the hype

There has been a definite Passivhaus buzz about this year’s Ecobuild. The Passivhaus SIPSHAUS pavilion has acted as a centrepiece for this, surrounded by a whole host of Passivhaus suppliers and organisations.

There also seem to have been a lot more Passivhaus-related talks this year (albeit still on the ‘fringe’) – many of which have been honoured by the presence of Prof Wolfgang Feist, founder of the Passivhaus Institut, himself.

The Passivhaus Trust ( N32), which now has upwards of 75 corporate members,  has been very proactive in a number of these events including the excellent debate ‘Driving Passivhaus delivery in the UK’ which asked its eminent panel ( including Prof Feist) what the push factors were for Passivhaus in the UK (robustness, cost-effectiveness, usefulness of PHPP as a design tool,  sheer common sense) and also explored some of the factors which have been slowing it down (fear of MVHR systems, unskilled construction industry, confusing ‘zero carbon’ Government agenda etc).

There were calls for the standard and term Passivhaus not to be debased and for the need to prevent ‘Passivhaus hype’ and people bandying the phrase about without being able to back it up. There were also calls for an ‘integrated design process’ – involving designers, builders and clients in all stages of the build - a subject close to my heart.

There was also an excellent series of talks on Passivhaus refurbishment – including a look at the forthcoming EnerPHit standard for refurbs (due to be released this June).

Rob Prewett and Justin Bere both spoke about their Passivhaus refurb projects – which offered useful general ideas on refurbishment – including consideration of design of hot water systems in Passivhaus projects and an intriguing method which involves the use of inflateable bags to make sure windows are placed correctly.

The need for awareness of interstitial condensation in refurbs, especially when using internal insulation, was also discussed.

The jury is still out on the financial viability of Passivhaus refurbs as analysis of all the costings of TSB retrofit for the future projects has not yet been undertaken but it sounds like costs have varied considerably, obviously depending on the original condition of the house before the refurb.

In terms of products, as well as our own Passivhaus window and MVHR launches (stand N53), we have noted some very interesting wall system developments including Passive wall ( S1259), NBT’s Passivhaus systems ( S1111), and a sneak preview  (at Ecological Building Systems stand S951) of the new Calsitherm Extra internal insulation system for masonry walls (which, thanks to its moisture capillary action, gets around the problem of interstitial condensation problems with internal insulation).

As well as the new Alphawin window from OPTIWIN (at our stand N53), Reynaers (stand N360) have launched the CS104 aluminium window with Uw value of.077 W /m²K. We also spotted the Itho Advance MVHR system (stand S2020) and the excellent - but unlikely-sounding - Caribbean Blind company (stand N42) which offers products to help prevent overheating and regulate solar gain.

Passivhaus kit homes are offered by Touchwood Homes (S1255) or Hanse Haus (N54). I also like the Isoquick insulation raft foundation system for Passivhaus foundations (at stand N49) and the Simpsons Strong Tie joist-hangers (for airtightness detailing) used in the Passivhaus SIPShaus (N140).

I’ve been involved as a judge in the Isover Multi-Comfort House competition, which has been an eye-opening experience- judging student designs of Passivhaus-inspired Manhatten skyscrapers – not something I’ve had that much experience of!

 It has been good to be joined by Nick Grant from the Passivhaus Trust and, of course, Professor Feist. The winner was announced today (Wednesday 2^nd March 2011) as being the ‘Green Canyon’ project.

Congratulations to all the students involved who have put loads of effort in. I’ve also enjoyed meeting up with the ever-growing band of Passivhaus enthusiasts at Ecobuild – many of whom are fellow Twitterers – and it has been really good to put faces to names.

The final day of Ecobuild  still offers some Passivhaus treats – including three Passivhaus talks  in Ecobuild fringe. Maybe see you there!