Heating
We reluctantly gave up waiting for the arrival of micro CHP boilers and went ahead with the installation of a new gas condensing boiler in September 2008. This significantly improved our gas efficiency for space heating (by around 30%).
We've also dome some other things to make the heating system more efficient:
Heat recovery extractor fans
We had a Vent Axia heat recovery extractor fan installed in the bathroom in July 2009. This provides ventilation and reduces condensation, without the heat loss of normal bathroom extractor fans. It has 2 settings, normal, which is on trickle rate all the time and uses 2 watts (18 kWh a year) and a boost setting eg for when someone takes a shower. We calculate that this will use slightly less energy than the old fan but the main purpose is to reduce heat loss in winter. An unexpected bonus is that it has made the bathroom ideal for drying washing in the winter when it won't dry outside. In February 2010, we had another one installed in the kitchen.
Lighting
It was easy to switch the main ceiling lights to LED bulbs. We now have only LED bulbs in all our lighting. It was complicated to adapt some lamps and to get a thorough understanding of the various types of spotlights - lumens, colour rating etc.
Kitchen gadgets
Most of our kitchen gadgets are fairly old so we are caught in the dilemma of when is best to replace them – new low energy use models v the carbon cost of replacing things that ain't yet broke.
Standby
We've used individually switchable distribution blocks and adaptor sockets to reduce the number of gadgets left on standby.
Water heating
Since the installation of the condensing boiler and solar water heating, we've given more thought to our water heating. For one thing, we now have much of our summer water heating without using gas although we have enjoyed the challenge of thinking of the best timing for running the washing machine etc. Also, without the instant hot water we had with the old combi boiler, we've had to give thought to the subject of when and for how long to set the boiler to heat the water in the tank. In the second winter, we became more efficient at only heating the water we needed. We also got rid of the bath and now just take showers which reduces energy use for water heating and frees up space for drying washing in winter.