Craigrothie Passivhaus
Fife, Scotland
A recently completed project, led by Passivhaus Associates, this 2-bed bungalow, near Cupar in Fife has a treated floor area of 81m2 and has been built to the exacting requirements of the Passivhaus standard.
Due to site conditions and planning constraints, the project had to be built on one level, which resulted in a challenging building form – with a high ratio of heat loss area to useable floor space – creating challenges within PHPP which the design team successfully managed to overcome.
Built using a timber frame construction, the house will have a minimal heating load of 800W on the coldest of days. It has achieved an airtightness of 0.28 air changes per hour (0.36m3/m2h) @ 50 Pa and the U value for walls, floor and roof is 0.08W/m2K. The project was built to a modest budget of £165,000 or £1800/m2.
Optiwin Alu2wood windows from Green Building Store were specified for the project, offering a whole window U value of 0.77 W/m2K, combined with cork frame insulation and low maintenance aluminium cladding on the outside.
According to Graham Drummond at Passivhaus Associates: “ I am familiar with Optiwin’s Passivhaus windows as I had visited Optiwin’s factory in Austria a few years ago. I liked Alu2wood’s low maintenance specification and found that Alu2wood offered the best value for money compared to the alternatives available. I also liked the fact that Optiwin offer alternative glazing options (eg glazing with high-G values), which we needed for some of the windows at Craigrothie to help with solar gain.”
In addition, Passivhaus Associates also specified Green Building Store’s Ecopassiv glazed doors for the project. Ecopassiv offers a Passivhaus compatible range with a whole window U value of 0.75 W/m2K. Graham Drummond said: “We needed a lot of glazing in the project to help with solar gain and, in effect, treated Ecopassiv doors as windows within PHPP. Ecopassiv met our performance and cost criteria and offers an excellent option for glazed doors in Passivhaus projects. Both the Alu2wood and Ecopassiv ranges are high quality, beautifully engineered products. Green Building Store’s technical product knowledge also offered a distinct advantage over other suppliers. We appreciated being able to get detailed information and advice from them on the products.”
Passivhaus Associates also chose Green Building Store to design the MVHR and ducting system. “Through our involvement in the AECB we were aware of Green Building Store’s expertise in this field and specifying them for MVHR design seemed the logical and obvious choice. We appreciated the chance for dialogue through the design process, which led to the design evolving as we went along”.
The Craigrothie Passivhaus is open as a showhome until early 2012. It will also be open for the Passivhaus open days 11-13th November 2011. For more information, contact Graham Drummond on 01334 470703 or email: graham@passivhausassociates.co.uk
Completed: October 2011
Passivhaus certification: in process
Consultant: Passivhaus Associates, Tel: 01334 470703, www.passivhausassociates.co.uk
Architect: Locate Architects, www.locatearchitects.co.uk
Certified Passive House Designer: Chris Morgan, Locate Architects
