10 Top Tips for a Green Home
Top Tip 1 Design – Think about how much energy you want your house to consume in 10 years time and design for that.
The decision on a traditional brick-and-block box consuming 30,000kWh of energy each year or a zero carbon home is made at the design stage. It is the one opportunity to orientate the house to the south, choose construction to maximise insulation potential and to get rooms in the right place to take advantage of natural light and heat.
Top Tip 2 Materials – Pick a construction method that lends itself to the use of sustainable materials – timber frame for instance.
The average house contains about 200 tonnes of materials and about 40 tonnes of embodied CO2. It is possible to build a house entirely from sustainable and recycled materials. Possible but difficult. See what is available in your area and check out if sustainable timber, sustainable insulation and the like really will be that much more expensive.
And eliminate the big things – like rainforest timber, aluminium and (the Great Satan) PVC – before moving on to the smaller things.
Top Tip 3 Insulate – Doubling the thickness of insulation will increase the cost by less than 25% - the labour element remains largely the same.
Insulation is King in an eco-build and whether the insulation is Rockwool or Kingspan, sheep wool or cellulose will depend on preference and budget. The issue is to make sure you have enough of it. Set a target U-value, 50% improvement on Part L building regs is a good starting point, and make sure there is room to get the insulation in.
Top Tip 4 Lighting & Power – Halogen bulbs are not energy efficient. Use LED’s or compact fluorescent.
The average kitchen will need at least 8 halogens at 50W each. LED’s will give the same amount and quality of light for less than 100W. As the proliferation of electrical equipment has increased so the amount of electricity used by the average household has increased – at a steady 2% per year since the 1960’s. The good eco-house will minimise its electricity consumption using things like low-energy lighting, power-down plugs and A-rated appliances as a minimum.
Top Tip 5 Water in – Low flush WC’s, flow regulated taps and A-rated appliances will reduce water use by 22% - up to Code for Sustainable Homes level 3.
The amount of water we use in the home has increased by 300% since 1950. Unfortunately, and contrary to the apparent evidence, rainfall has not increased to keep pace. It is becoming increasingly necessary (and cheaper) to minimize our water use. The items mentioned above have a significant impact on consumption with little or no impact on convenience.
Top Tip 6 Water out – Use rainwater to flush the toilet and save 30% of your water consumption (and 30% of your water bill).
The Code for Sustainable Homes requires that the surface water run-off is no greater than the previous conditions for the site. That means that at least some of the rainwater falling on the site must stay on the site. Typically a rainwater harvesting system is the cheapest and most effective way of achieving this – and defeats the hose-pipe ban.
Top Tip 7 Ventilation – Add heat recovery to your ventilation system and save energy (and money).
The well insulated, well sealed house is going to need ventilation to maintain oxygen levels and a healthy environment. The options are trickle vents, a whole-house ventilation system, or a ventilation and heat recovery system. Mechanical heat recovery is the best way to introduce fresh air in a controlled way and re-use the heat already in the house.
Top Tip 8 Heating Controls – Fit a system that will allow the temperature of each room and the times that it is heated to be properly controlled.
Turning the thermostat down 1.50C will reduce the heating energy consumption by 10%. But the heating control system has to be sufficiently sensitive to allow that reduction. Heating only those rooms that are in use could reduce the energy consumption by another 20%.
Top Tip 9 In the garden – A vegetable plot will produce tasty food and save to CO2 emission in growing, transporting and buying the food from the supermarket.
The good eco-build will look at the garden as closely as it looks at the house. It is an eco-system and a resource but over to lawns and patios it is little more than a desert. Considered planting, some “wild” areas and a veg plot turn it into an area with an abundant and interesting eco-system, full of wild-life - and the source of home-grown veg.
Top Tip 10 Renewable Energy – 75% of the energy used in the home is for heating and hot water. Invest in heating technology before electricity generation.
Obviously the big one in eco-build terms, but it does not need to be. Design well, build well, minimise your energy needs and buy only the systems you need. Renewable energy systems are not like traditional systems. They need the same level of thought, consideration, design that might be lavished on the kitchen or bathroom. Well designed renewable energy systems will be more effective and save more money than those added as a after-thought.