Gooman

Thanks everyone for your suggestions so far. Any comments on the thoughts below would be most appreciated! As we're adding rooms in the garage conversion we'll need to heat them. The warm air system can't be extended, so we either need to add another boiler just for those rooms, or replace the whole system. We also need to insulate the solid concrete ground floor in the existing house, but can't afford to rip and replace. Existing ground floor is approx 74m2. We're probably just going to go with Mr Punter's suggestion of 30mm Celotex and chipboard. Given that, we probably shouldn't/can't go with an ASHP and rads but will just have to use a modern combi boiler. The garage being converted has the floor 100mm lower - so not enough room for a reasonable level of insulation for UFH (from what I've read, 300mm is recommended). So we'll probably have to do rads rather than UFH, and I'll just use PIR/chipboard flooring panels to bring the level up rather than a concrete fill. It's a shame. I'd like to be more environmentally friendly, but we a) have to live in this house while we renovate it and b) don't have the budget to go the whole hog!

In fact, would it be feasible to use something like this: https://underfloorheating-direct.com/25mm-floating-floor-panels-26519-p.asp with Celotex under and an engineered floor straight on top? Not yet looked into u-value calculations ... that's a can of worms I guess I'm going to need to get into!

We're planning to convert a garage into a habitable space. It has a concrete slab floor, 100mm down from the concrete slab for the rest of the house. How much depth would we need if we wanted to put UFH in the garage floor? We could raise the floor in the adjoining room (kitchen) to match if it's not too much extra.

Isn't Aerogel as expensive as VIPs? There's definitely no asbestos in the vent system itself - the survey was outstandingly comprehensive and thorough. Only places it's present in the heating system are on the inside of the door of the boiler cupboard and in the cement flue in the loft. The cupboard door will be disposed of in one piece, and the flue in the loft will stay where it is.

I'm a big fan of Click in general - huge range in a good selection of finishes, at a reasonable price. Click Mode is very handy, as you've said. Only downside I've found is that their dimmers are (or at least were - last bought them 5 years ago) rubbish. Leading-edge rather than trailing edge and no soft start. Played havoc with the transformer in my halogen lights.

I've heard that a lot. It is a new (in last 12 months) boiler too (Johnson & Starley J50) ... but the big problem is that we can't extend it to cover the garage conversion, plus we want to get away from the electric immersion heater for hot water. It's possible we might just add a combi boiler for the garage conversion and hot water - we'll decide that when we've lived with the warm air heating for this coming winter.

Thanks for the tips! Have looked into Vacuum Insulation Panels (VIPs) for insulating the concrete floor but it's looking very expensive. Celotex might be the way to go, though since the lounge is huge the cost of carpeting will also be high so we'll probably live with parquet and rugs for a while! Forgot to mention wall and roof insulation - wall cavities are insulated. Roof is only 100mm insulation so one of my first jobs is to pad that out to 270mm (after adding lap vents as there's currently no loft ventilation). From looking in the loft, it looks like regular loft insulation has just been stuffed down the sloped areas behind the plasterboard - might be possible to remove that and slide Celotex board down from within the loft.

Hi! We're buying a 1970's-built 3-bed detached chalet-style house in Bedfordshire. Apart from a lick of paint and a recent bathroom, it's pretty much unchanged since built: Gas warm-air heating (ducts, and lots of 'em) with electric immersion heater for hot water Parquet floors to lounge, hallway and dining room which needs resanding, filling and sealing (plus filling the gaps left when we remove the warm-air heating outlets) 1970s kitchen, including sliding-door cabinets! Our aspirations are: Immediate - Convert current tiny utility and the end of the double-length garage into a new dining area flowing off the kitchen, plus new utility and (probably) downstairs shower room Immediate - Roof lantern and bi-fold doors onto garden in new dining area Immediate - Replace warm-air heating, ideally with something more environmentally friendly Medium term - New kitchen (self-fitted) Long term - Replace tiling on gable ends with cladding (possibly cement board e.g. Marley Eternit) Challenges are: Three-gabled (T-shaped) chalet roof limits possibilities upstairs unless we put in dormers (which we don't have budget for and which would be tricky anyway due to multiple gables) No space to add a shower to upstairs bathroom unless we make the small bedroom smaller and so thinking of downstairs shower Existing ground-floor spaces are concrete floor with no inbuilt insulation Garage floor is about 6" lower and so when we raise floor we'll have to raise the roof too Extending heating to the converted area of the garage - warm-air ducts can't be extended (and we don't think we're fans of it anyway), so thinking of wet under-floor heating in conversion and replacing heating in rest of building with traditional wet rads Asbestos throughout (we've had a specialist survey) including soffits, boiler flue, roof tile underboard, boiler cupboard door, utility ceiling, Marley vinyl floor tiles in kitchen (only the last three of these areas are likely to be touched though) Budget for immediate stuff is £30k. Conversion could be £20k, leaving only £10k for heating changes. Looking for: Bright ideas on heating. Keen on ASHP but as we need new rads could be beyond our budget. Might have to settle for modern combi-boiler Any genius insight or pointers to existing posts on any of the above!