Thursday 15 December 2011

Certified !!

We've just heard that the certification of all the units came through yesterday from the PHI in Germany. Obviously really pleased to get this seal of approval, and plaques for the buildings are now on order, (to be fixed with thermally bridge free fixings of course!)

The Wimbish Experience days are going really well, and I understand we are now full until April. The feedback from the tenants has been absolutely wonderful, it's so good to hear them talk about the low fuel bills and comfort of the homes. I know we always knew it, but when a tenant tells you how wonderful they are and that her gas bill for 6 months was just £30, even in the really cold snap we've just had, I think the whole team can allow themselves just a small element of self-satisfaction.

I've put some images here of the finished product, although of course landscaping always takes some time to have an effect.

Our next 14 passivhaus are well underway at Ditchingham and we look forward to a similar result there.

Chris Parsons
Parsons + Whittley Architects

Thursday 27 October 2011

Monthly Visitor Experience proves to be great success

Following the first two successful visitor experience sessions and due to high demand we have released additional dates in 2012.  The sessions feature presentations from Hastoe and the architect Parsons & Whittley, along with an opportunity to view three of the house types.


  • 6 March 2012
  • 3 April 2012
  • 8 May 2012
  • 12 June 2012

Frequently asked questions and answers coming soon.

Ulrike Maccariello, Hastoe Development Manager

Tuesday 12 July 2011

Rural communities do lead innovation

As residents move in to our completed Wimbish Passivhaus project, we feel very proud to have worked with Wimbish Parish Council and the community to show that affordable homes in rural villages can make positive changes to the way we approach design and build; to protect the climate and tackle rural fuel poverty.
Investing in this exemplar scheme, at an additional cost of 10%*, has taught us a great deal about what we can achieve in our future programme.  The lessons learnt are already being replicated on site at our second Passivhaus development in Ditchingham, Norfolk and the uplift costs have been limited to 6%*.  We will be developing more Passivhaus schemes after that.  

This experience has proved that overcoming the challenges associated with developing homes for local people, in sensitive rural areas, can go hand in hand with cutting edge techniques.  We’re pleased to be supporting the National Housing Federation’s Rural Housing Week (11-15 July) and showcasing Wimbish as part of that.  

We’re also hosting a monthly visitor experience from September, to share more about the project with professionals from the sector and I hope you might be able to join us on one of the dates shown below:


·         6 September 2011
·         4 October 2011
·         8 November 2011
·         6 December 2011
·         10 January 2012
·         7 February 2012
·         Further dates 2012 will be announced in due course

Sue Chalkley, Chief Executive, Hastoe

*determined by comparison to an equivalent Code Level 4 development in the Hastoe programme.

Friday 25 March 2011

TSB funding secured for in-depth study

I’m really pleased to say that Hastoe has secured funding from the government-backed Technology Strategy Board to monitor the in use performance of our Passivhaus homes.

It was one of only five domestic projects, along with ten non-domestic projects, to be successful in its application to the second round of the Building Performance Evaluation Competition, open until 2012.

We’re now into the next stage of planning for the monitoring of the development which will take place over the next couple of years. This monitoring will enable questions like the following to be explored:

·         Is running the buildings as cheap as it has been designed to be?
·         How much does the energy use vary between homes, and how does the difference break down?
·         Are comfort levels and air quality maintained in all homes through all seasons?
·         Is the solar thermal system effective in providing hot water and heat?
·         Are residents happy with the heating and ventilation systems?

To answer these, we will be looking at:

·         The handover of the properties to residents
·         How residents use the technology, following on from early training with Hastoe
·         Behaviours and steering residents to get the best from their homes
·         Full monitoring every few minutes, every day of
o    the temperature, humidity and CO2 levels in several rooms
o    the external temperature, humidity and sunshine
o    all hot water flows in the heating system, together with the electricity used
o    the quantity of gas, electricity and water used by each house
o    energy consumption of the ventilation system and air flow temperature
o    sub-metering to determine where electricity is being consumed. 

The study will fully monitor one unit from each block; that is one three bedroom house, one two bedroom house, and one flat.  The remaining 11 units will have reduced monitoring that will help provide an even wider knowledge base, and to provide context for the more in-depth research.  The utilities and the internal environment of one room will be monitored; sub-metering and electricity used by the heating and ventilation will be recorded.

Looking at the project so closely will mean we can learn a lot, and share these lessons across the construction and housing sector as the results are collated.

We’ve been supported in the application by Build with CaRe, an international project aiming to help mainstream low carbon construction in the EU.  They’ve been monitoring low energy homes since 2009 and in the East of England partner with the University of East Anglia, West Suffolk College and Southend-on-Sea Borough Council.

This monitoring project will make it possible to share the true benefit of Passivhaus principles and promote low carbon construction in housing.

You can find out more by seeing our full release here.

Ulrike Maccariello, Development Manager, Hastoe

Friday 18 February 2011

Initial Air Testing

Visited site today to witness the first air testing of the properties. The air tightness strategy is not yet complete, as the main air barrier is the wet plaster, but as we are getting close, and all of the membranes are fitted, or nearly fitted, we thought it was worth testing the units to see where any unforeseen problems might be occuring.

Dominic had skilfully mounted the Wincon unit in a panel and fixed it into the door opening, and wound the pressure up to 50 Pascals to see what was giving. Initial testing just by hand highlighted some problem points in the ceiling Intello membrane, and a few leakages around Internorm's factory fitted Illbruck tape but on the whole nothing really surprising. Sealing of a few service penetrations was happening whilst the test was underway and then a closer investigation with a smoke pen highlighted some more suspect areas.

The boffins will work out the actual air leakage on a rough and ready measure over the next few days, but at least we have started to find the weak spots in the design/construction before we plaster.

The other exciting development was to see the insulation being fixed in earnest. This has been delayed for a couple of reasons but now that it is underway the buildings start to take on a bit of texture as the windows settle into the cosy covering of 285mm of Springvale's Platinum EPS. With a Lambda of 0.030, this, coupled with the rest of the wall construction, will give a U value of 0.080, making it the most thermally effective wall we have ever undertaken.

We also showed a journalist from Greenbuild magazine around this afternoon, and talked to her at some length, (my friends down the pub already call me a passivhaus bore!), about the project, the challenges we have faced, and the issues the scheme has presented, but on the whole, still a positive experience and a sense of expectation is gathering as more and more of the final elements fall into place.

Chris Parsons

Parsons + Whittley Architects

Tuesday 8 February 2011

Weather relents and progress regained!

So, once the weather relented in January we were at last able to make some real progress on site. Firstly the external insulation was fitted between the rafters to allow the roofing to continue. Fiddly this with the extended rafter foot needing to be accommodated within the insulation zone, but essential to maintain progress.

Then window fitting could proceed at last, and some experts from the supplier soon had these in place. Remarkably this seems to transform the site and it begins to take visual shape. Extended protection has been applied to protect the PPC finish, and the extended sills look exposed awaiting the insulation placement.

Insulation placement has been a problem as both air and surface temperatures need to be above 5 degrees, so maybe January wasn't the best time to try and do this, but things are warming up and so hopefully we'll soon be wrapped up nice and warm.

Fortunately it is not on the critical path, so Bramall have been busy internally, first fixing mechanical and electrical, including the MVHR ducts.

Further work has been going on as well on completing the various membranes and tapes in preparation for an initial, pre-plaster air leakage test. Although the plaster is our actual air leakage membrane, it is felt worth testing before plaster to see if there are any unforeseen areas that may need attention. Bramall have purchased their own 'hovercraft' as it is known and we anxiously await the first test results.

The photo here shows the air tightness tapes around the window and door frames before sealing to the walls, and the DAS tape at the junction of the wall to the floor. All of these get plastered in so as to link to the air tight plaster membrane.

And I can't sign off without congratulating the Bramall site team on the quality of the catering at site meetings which is much improved since my first blogged comment!
Ahh, the power of the internet!!

Chris Parsons
Parsons + Whittley Architects.
Feb 2011

Wednesday 26 January 2011

Interim certificates confirm site on course for Code 4

All the units on the site have been issued with their design stage Interim certificates under the Code for Sustainable Homes (May 2009) and are on course to get their final certificates once complete.

The Code 4 pass mark of 68 percent has been comfortably exceeded with dwellings scoring between 72 and 77 percent. Although not outstanding in itself these results are particularly pleasing given that there are tensions between the Code and Passivhaus that make some credits harder to achieve.

These areas include:

• Secured by design (Man 4) – although Passivhaus windows and doors (Internorm Edition are being used at Wimbish) have excellent locking mechanisms they do not have the SBD approvals that is often required by police Architectural Liaison Officers.

• Global Warming Potential of insulation (Pol 1) – nearly all insulation used on the site has a GWP of less than 5 but the German Passivhaus loft hatch supplier was unable to provide any evidence of this. Consequently the credit could not be achieved.
• Responsible resourcing of materials (Mat 2 and 3) – many of the materials were sourced from suppliers where the necessary certification could not be guaranteed and so the Code strategy set early in the project was to not pursue these credits. It is likely that a number of credits could have been achieved if necessary. More ‘Code compliant’ products could have been used but these often do not have the certification required for Passivhaus.

• Energy and Carbon (Ene1) – a gas heated Passivhaus should achieve a good score in this area but there are a number reasons why this is not the case. Firstly there is a well recognised problem in the Code with flats and mid terraces whereby the small amount of external surfaces makes it hard to show significant carbon reductions through insulation measures. The flats only narrowly achieved the necessary 44% reduction in carbon emissions (block average). PV could have been added if really necessary for Code compliance but this would not have helped Passivhaus performance since it focuses on rewarding demand reduction. Thirdly the non-standard (for the UK) heating strategy of a thermal store supplying a wet heating coil in the MVHR supply air duct cannot easily be entered in the SAP calculation making it hard for the likely carbon reductions to be recognised in the calculations.

These issues will all be resolved in time as the supply chain recognises the importance of both sets of certification. More products and UK suppliers in particular will all help to push down the cost of achieving Passivhaus in the UK.

Nick Jones, Associate Director, Inbuilt