Located in a rural setting in the South West county of Galloway, Scotland “The Houl” is an award winning low carbon house for the architect Simon Winstanley and his family. The architectural brief was to create a contemporary building recessed into the landscape using lightweight construction and be energy efficient.
The house is super insulated (to Passivhaus standards) clad in untreated cedar which will weather to a grey colour. The roof is standing seam zinc and the windows and doors are timber triple glazed. All excavated materials during construction were re-used on site. The timber frame was lined (inside and out) with a reflective foil thermal membrane to improve thermal performance.
The angle of the roof to the main living area follows the site slope with the lower rear pitch meeting the upper roof at a lower level to allow morning sunlight to penetrate the centre of the house. The entrance is sheltered from prevailing winds.
Direct solar gain is maximised with large areas of West facing glazing and the house features an air source heat pump powering the underfloor heating. Low air infiltration (another Passivhaus technique) was achieved and a whole house MVHR supplies fresh air. Supplementary electricity is generated by a wind turbine.
Gross internal floor area 182m2 or 245m² (including car-port and storage)
Total cost: £306,000
Cost per square metre: £1,250 (including car-port and storage)
Annual co2 emissions: 0.6kg/m²/year
On-site energy generation: 32%
U-value averages Walls: 0.15W/m2K, Windows: 0.7W/m²K, Ground floor: 0.17W/m2K
Mains water consumption None. Water supply from bore
As the architect outlines, the house can be called ‘zero carbon’ because it features:
- Energy efficiency (highly insulated, minimal air infiltration);
- On site microgeneration (wind turbine);
- Low or zero carbon energy technologies used (MVHR and air source heat pump for heating).
“A zero carbon house design will pay back the carbon invested in its construction through exporting zero carbon energy back into the national grid.” Simon Winstanley
Is this how future home design can meet our emission reduction targets?
Credits: Images linked to sources.