we live in a 3 bed semi which is built of concrete, it gets damp on exterior walls and is always cold. boiler is 11 years old and we have to turn the heating off to get hot water. i think we need a new boiler, maybe a condenser and maybe move it into the loft. we can't have cavity wall insulation as there is no cavity so think we need exterior like a cladding but not sure how effective thet is. or interior insulation and therefore have to redecorate every room and possibly retyle bathroom and kitchen. bathroom and kitchen have not been changed in over 11 years and therefore while retyling we would need to do whole rooms. i think that is going to be so much work and money we could move to a normal build house for less than the diy costs. just needed to write all this down to sort it out in my head.
There are strict building regs/gas regs requirements as to where a new boiler can go and where its exhaust can vent (you might not be allowed to put a new one where the old one is, like us), so it's a good idea to speak to an expert first. Have you got/can you install an immersion heater in your hot water tank?
Ours isn't a combi. The engineer who came to fix it for us recently told us that if we replaced it, a new one can't go in the same place because although it is on an outside wall (which is apparently now mandatory for gas boilers) and vents onto our property, the vent is too close too the boundary with next door's patio. It may be different with electric ones.
Because you have to turn your heating off to get hot water there is definitely something wrong and it would probably reduce your gas bill if you had a new boiler put in.
When we had new combi boiler in as it is a condenser it has to have somewhere to drain so they have to pipe it to a drain outside or into an existing pipe (like mine as it is above my washing machine)
To have that for 3 bed detached house and have 10 thermostatic radio valves put on a to move a radiator and replace it was £2300. We are in Yorkshire.
Maybe someone who has a concrete house can come along and help you with that bit.
I suppose all this depends on how long you are planning to stay in your current house, although kitchens and bathrooms do sell houses and there are some real bargains to be had because of the credit crunch.
the house is nice in that it's got a big garden and isn't overlooked but it's in a bad area and is ex-council so wouldn't sell for much. if i could sell our house and get another one for £20000 more i would go for it but i don't think it would be possible to get a nice 3 bed house.