We are currently without central heating in the house because we have to connect the system up to the new radiators in the conservatory, study and guest bathroom.
The house is well insulated anyway & we don't actually use the central heating very often because it always seems such a waste. The house holds the heat quite well anyway nbecause there is double glazing right through and also the cavity walls are insulated. The roof space is also insulated with rockwool. In the new extension the ceiling/roof has 8 inches of insulation, the walls are insulated with new super duper high tech rolls in between the actual layers of the wall. We havea also insulated under the wooden floors. We have a gas fire in the sitting room but we havn't yet put that on either. It makes the sitting room quite warm but some how we have been avoiding it.
Instead we have just put on a few more layers. It is the easiest thing that you can do towards keeping yourself warm when there isn't a heat source. But we have a few more tricks up our sleeves as well. We open the curtains in the south facing windows as soon as the sun comes around that way and ensure that we are maximising the suns rays that we can catch. We shut the curtains slightly before it gets properly dark to retain some heat from the sun. Unfortunately there is a flaw in our plan here. The heavy velvet cutains with the thermal lining are somewhere in the attic. I am getting to them but we wont get best use of them really until next winter.
We also have the downstairs of the house entirely open plan (except bathrooms etc). This means that we get the warmth from cooking, from the dishwasher, the washing machine & tumble dryer. The oven is quite efficient so I am not afraid to use it when required. The dish washer gets used most days (it is A rated efficiency). The washing machine takes quite a large load and feeds from cold so it isn't useful for contributing warmth. The disadvantage is that we also get the smells of cooking and noise but it doesnt bother us (if it did then we would build walls but we like to be within shouting distance of each other).
So all this leads us to the place we are now. I am in my PJs in bed, with a cat and a husband for warmth (two cats woul dbe more efficient but sadly the cats won't be friendly with each other even when i need the heat), wearing bed socks resting my laptop on my PJ legs. Surprisingly comfy considering you can see my breath when I breath out!