How to Build a Sustainable Home: Designer's View

“Reduce Your Need for Energy”

Richard Hawkes, the architect-owner of the above house, specialises in designing ecological homes (hawkesarchitecture.co.uk). Here, he gives his top design tips:

• Invest in your building envelope. Before spending money on energy generating technology, reduce your need for energy in the first place.

• Design out the need for heating. Try to get to a point where you don’t need a heating system. This will save you a fortune.

• Don’t design around payback periods. These may be inaccurate.

• Don’t buy cheap windows. Energy-efficient high-quality windows are about the best investment you can make.

• Insulate! Use as much as you can afford — and then add extra.

• Choose a builder and architect with a passion for sustainable design. Educating someone is likely to be time consuming. Go and see their work; meet previous clients.

• Build in lots of thermal mass. This will keep a home warm in winter and cool in summer.

• Orientation. Maximise south-facing glazing to take advantage of passive solar gain. At the same time minimise north-facing glazing and avoid rooflights, as they will lose heat.

Hawkes Architecture bases its design philosophy on PassivHaus principles (hawkesarchitecture.co.uk, 01580 895106)

“Mass Needs to be Inside”

Meredith Mole of Mole Architects (molearchitects.co.uk) tackles the debate between the two main approaches to sustainable design, ‘Light and Tight or Mass and Glass?’:

“I have lived in a well-insulated timber frame house since 2003. There are plenty of energy-saving measures and solar shades above the windows prevent summer overheating.

“On subsequent houses we have continued to use a well-insulated timber frame but added thermal mass inside the building where it will have the most effect in balancing out momentary heat loss or gain. In most of our houses we build internal walls in dense blocks, or bricks, as well as stone or screed floors. This absorbs heat from the room, and emits it in the evening when cool.

“The catch-phrase ‘Light and Tight or Mass and Glass?’ is not so clever when we really look at it. All buildings should be ‘tight’, preventing heat loss. And all buildings benefit from some thermal mass — although this needs to be inside the thermal envelope to be of any use.”

Meredith is the principal of RIBA award winning Mole Architects, specialising in environmental design (molearchitects.co.uk, 01353 688287) 

Further Reading:

• How to Build a Sustainable Home
• How to Build a Sustainable Home: Design Solutions
• A Budget Sustainable Self Build