Andy’s home is a three-bedroom Edwardian end-of-terrace – a fairly typical example for its era, which has been extended to the rear and renovated in more recent times.
Andy is WinACC’s home energy consultant and was understandably keen to apply his knowledge and experience on energy-saving and renewable energy to his own home when he bought it in 2014.
Insulation and draughtproofing
The most important aspect of minimising heating energy use is insulation and draughtproofing. Fortunately, the property was already up to a good standard with 250mm of loft insulation and cavity wall insulation helping to keep the heat in. The weak spot was the suspended timber floor, however this was finished with an airtight laminate finish before it was purchased, so it was at least draught-free. As a result, the minimal additional benefit of installing underfloor insulation was not considered worth the cost and disruption of ripping up a perfectly serviceable floor finish.
The existing double glazed windows have been renovated with the replacement of many of the old sealed units with newer units with low-emissivity glass and “warm edge” spacer bars. All internal window draught seals have been replaced to eliminate draughts.
Heating and hot water
Central heating is supplied by an efficient condensing gas combi boiler to wall-mounted radiators, and controlled by a standard programmer on the boiler. All radiators have thermostatic valves, and some have programmable controls that ensure that rooms are only heated at the times when they are occupied.
In practice, however, most of the heating is supplied by a small 5kW woodburner burning tree surgery waste and briquettes made from waste wood – the central heating is usually only switched on for a short time on colder mornings. The room temperature is kept around 19degC in the day in occupied areas, and 21degC in the living room in the evening.
Lighting and appliances
All lighting is now LED, cutting energy use by 90% compared with old filament and halogen bulbs. The fridge/freezer, washing machine and vacuum cleaner were all selected as the most efficient models in their class, and the electric oven is an efficient A-rated model.
The east/west-facing roof is almost completely covered with a 4kW solar photovoltaic system, with eight panels on each aspect. The system generates around 3400kWh per annum, and offsets around one-third of household electricity usage.
Following all the improvements, gas use was reduced from around 5000kWh per annum to 2000kWh per annum – 1000kWh of which is hot water use. Electricity consumption from the grid is around 1000kWh per annum, although actual use (including power from the solar PV) is around 1500kWh.
For comparison, the estimated average consumption for the postcode is 4000kWh for electricity and 10,000kWh for gas, although of course some households will have more than one occupant!