LEAP has completed this Passivhaus in the North Pennine Area of Outstanding Natural Beauty
Located in the North Pennine Area of Outstanding Natural Beauty, Steel Farm, near Hexham is a recently completed Passivhaus by low energy building pioneer, Mark Siddall, founder of LEAP: Low Energy Architectural Practice.
Although the clients were concerned about the environmental impact of their home, their main requirement was for a house that would be comfortable whilst reducing energy bills. This was the reasoning behind choosing the Passivhaus standard.
Due to its location the house was subject to strict planning restrictions. These required the facades to be natural stone and the house to be of ‘traditional appearance’. Cavity wall construction was chosen. This also utilised the local skills base in the area, whilst developing construction details suited to small and medium scale development.
These planning restrictions also affected the window layout. Window proportions were refined to reflect those of a traditional building in the Area of Outstanding Natural Beauty. The window proportions have been optimised to achieve high standards of natural daylight and solar gains. Smaller windows are located on the north, east and west elevations to minimise heat loss, whilst the south elevation features larger windows to optimise solar gains.
Siddall says: ‘In order to gain certainty that we could satisfy the Passivhaus standard we used the Passivhaus Planning Package (PHPP) to create an energy model. This was done at an early stage in the design process, before applying for planning permission. This enabled us to determine the appropriate area of glazing and other aspects that influence the energy performance. Ultimately our discussions with the local authority helped us reach an agreeable solution whereby the character of the Area of Outstanding Natural Beauty and the ambitions of the project could be preserved.’
Despite being on track to achieve Passivhaus certification, due to financial reasons, before the project completed the clients decided not to go down the route of certification. The project is therefore a declared Passivhaus rather than a certified Passivhaus.
Currently the calculated space heating demand stands at 14.1 kWh/m²/year and due to older white goods having been installed in the house, the primary energy demand is 85kWh/m²/year. It is hoped that once these are replaced with low energy appliances this will reduce to 66 kWh/m²/year. Even with these issues the primary energy demand is still significantly lower than that required by Passivhaus standards.
Though this is not required by the Passivhaus standard the house features a solar thermal system for domestic hot water and a reed bed system for the treatment of foul waste water.
Research carried out by the practice suggests that the average annual fuel bill for a house in the North East can be around £1,250. Based upon Passivhaus calculations, the bills for this house are expected to be around £260 per year.
The house will now undergo monitoring for the next two years and the Soft Landings process was used throughout the project.
Location Whitfield, near Hexham
Type of project Residential
Client Trevor and Judith Gospel
Architect LEAP: Low Energy Architectural Practice
Service Engineer Alan Clarke
Main contractor J.D. Joinery and Building
Planning permission received September 2011
Tender date April 2012
Start on site date July 2012
Completion date February 2013
Specific environmental targets Passivhaus
Space heating demand 14.1 kWh/m²/year
Primary energy demand 85kWh/m²/yr
Air tightness levels 0.35m³/m²@50pa
Annual predicted CO2 emissions
Wall u-values < 0.1 W/m²K
Floor u-values 0.1 W/m²K
Glazing u-values < 0.8 W/m²K