The best sustainable garden room will be thermally efficient and responsibly sourced – from sustainable elements. Thermal efficiency is a bit of an industry term but simply means that the building needs a minimum of energy expended on heating, cooling or dealing with condensation. Being part of the growing garden buildings market, here is the inside knowledge on what to ask your supplier.
1. SIP construction with a minimum of 100mm PU(polyurethane or XPS) insulating foam for ceiling, floor and walls for excellent thermal efficiency (building regulation approved quality) reduces your energy need to heat and cool the room. XPS SIP panels are almost twice as thermally efficient as polystyrene or EPS, helping with condensation issues. EPS panel efficiency is improving with larger wall thicknesses.
2. Double glazing K glass and high quality UPVC frames for windows and doors. The debate between aluminium and upvc for most eco-friendly frame rages on.
3. Full height glazing for maximum natural light; at least one full wall of glazing. This counters excessive need to use energy for artificial lighting.
4. Modern alternatives to the traditional concrete foundation.
5. Sustainably forested timber cladding. I prefer western red cedar because it requires no maintenance, has a long life and is naturally mould resistant.
6. Sustainably forested composite flooring and low emission paint to finish the internal walls.
7. Low energy halogen lighting.
8. Energy efficient appliances.
9. Eco options like sedum wall and roof planting, rain water harvesting, renewable energy sources such as a wind turbine or solar panel system or earth-powered heating.
10. Choose a company which actively practices an up-to-date environmental policy and offsets the carbon which they have to use.