Sunday 17 October 2010

Up to floor joist

As it took a while to get the website and blog up and running, my first blog comes as we await the first floor PC slabs for the flats.  For historical purposes, 400mm of Dow Floormate was placed without difficulty beneath the 300mm RC rafts, and the insulation is now all nicely wrapped up and backfilled. All the service penetrations were installed ready to receive air tight grommets and the blockwork commenced.

Most Passivhaus’s in the UK are built by enthusiasts for enthusiasts, but at Wimbish we are trying to build them in a normal commercial volume house building environment. That means getting your everyday subcontractor to understand the process and the importance of quality and detailing that wouldn’t normally apply in this environment.

Initially this included making sure the Aircrete thin joint blockwork was laid fair face to the outside rather than the inside, as the insulation has to be fitted later with no air gaps between the sheets.

Our air tightness barrier is to be the wet plaster but where we pass through the first floor void the ground and first floor plaster skins are linked by a Solitex Plus airtight membrane. Initially we had proposed PC slabs even in the houses because of the ease of obtaining this air tight seal, but value engineering changed this to timber posi-joists which present a few more challenges, particularly with restraint straps and in the corners. Several mock ups and some significant time and effort on site has been expended to ensure this is properly placed and installed.

So, the PC slabs should arrive on Monday for the 6 flats and then we can speed ahead to getting the roof trusses on. The next passivhaus task will be the air tight membranes at ceiling level, and then maybe a preliminary air test before plaster to see how we are doing.

Chris Parsons
Parsons + Whittley Architects
17th October 2010

Friday 15 October 2010

Site Visit Opportunity

Hastoe Housing Association in conjunction with the project team are facilitating a series of open events at the Wimbish Passivhaus site. The open events will provide a brief presentation followed by a walk around the site. Time for questions and answers will be at the end. The events are free but restricted to 15 attendees per event and a maximum of 2 people per organisation. The event bookings are on a first come first serve basis. For enquiries and bookings please contact

Upcoming events:
Tuesday 2 November 1.30pm to 3pm
Tuesday 7 December 1.30pm to 3pm
Tuesday 4 January 1.30pm to 3pm

Ulrike Maccariello, Development Manager, Hastoe

Tuesday 5 October 2010


Welcome to the Wimbish Passivhaus blog.  Along with our partners, we hope you find the information here and on our website a useful insight into this exciting example of how innovation and advanced building techniques can work for  rural affordable housing.  Hastoe is committed to the climate change protection agenda and we will learn a lot from this scheme – we intend to share this across the sector and take what we learn forward, to reduce the carbon footprint of all our new homes.  We look forward to receiving your comments.

Sue Chalkley, Chief Executive, Hastoe Housing Association.