Steve_

Sorry for the confusion, I don't currently have insulation, but by the time I have the ASHP installed I will be fully insulated, so I based my calculations on that. I just did a generic calculation on the .gov website and the figure came in at £6,300 for the RHI!

Thanks for the replies. When asking for quotes I stated that we currently have zero insulation! we are building 2 extensions which have cavity wall insulation and we will be installing underfloor heating throughout the whole house with insulated floors, we are going to use inslated plasterboard on all external facing walls and we will be adding loft insulation. We do currently have double glazing. Because we don't have a EPC I have looked for similar sized property in my area and used their EPC details to get a rough idea of what my RHI repayments would be. I based it on a "C" rating (worse case) and I think the RHI was about £8,500 minus the £5k green homes grant so we will still be paying about £3,500+vat. I've just emailed a few more companies asking for a quote, so fingers crossed!

Hello. I currently have a 8.5mL x 5.5mW x 3.5mH workshop. It's made from concrete side panels and a corrugated metal roof and it's been built on a 30 cm slab (It's 30cm on the outside, but I don't know if it tapers off towards the middle). The front is wooden shiplap which is in need of replacing and the workshop is at the lowest point of my garden and floods whenever we get heavy rain. I'd like to take the whole thing down and rebuild it to match my next door neighbours workshop which is 8.5mL x 5.5mW x 5.3mH as theirs has an office above. My wife and I will be doing the work ourselves. We'd rather it be a block build with a cavity wall as we do a lot of metal work and we'd like to work late at night so this would be best for soundproofing. If not we could do a timber build With thick insulation. My question is, is there anything that I can do with the current foundations (Slab!)?I If it will be un useable, what would be our next easiest options? Could we drill column footings and keep the slab as a floor? Is it a tear out and start again job? Thanks in advance for any advice. Steve.

Hello. First off, I’ve been reading a lot about ASHPs on this site so if you’ve ever posted on this subject I’ve probably read it so thank you very much! My wife and I are in the process off planning our new heating source. We are not on mains gas so have a wood burning stove with a back boiler, an immersion tank (which we never use) and an electric shower. We like the idea of having an ASHP with underfloor heating throughout but I have a question about the install and I was hoping that someone might be able to give me some advice. We will be having it installed by an MCS accredited engineer, but I has wondering how difficult the install is to justify the roughly £4-£5k install cost. From all the videos and articles that I’ve seen it doesn’t seem that difficult (if you know what you are doing!) We’ve had a few quotes (please see attached) and they range between £9-£12k. If a Mitsubishi ecodan costs about £6k I just can’t understand how the labour cost can be so high if it’s only a 1-2 day install. We were going to go through the RFI scheme, so I was guessing it is a case of the installers know how much you get back therefore they raise there price accordingly. Or it costs a lot to get the MCS certificate so they have to get their money back. The only quote we’ve had so far from an installer listed on trust mark (so that we can take advantage of the green homes grant) is for £12k plus VAT but I’m very sceptical of him because according to companies house his company was only created this year and he is listed as a recruitment consultant, which makes me think that he is just farming the job out and adding his cut on top (plus the only search hits for his phone numbers come from his website). My wife and I do lots of work ourselves as we’ve had some high quotes in the past and we will not pay for something if we can do it ourselves. Any advice will be gratefully received. Basically, I’m just wondering why it costs so much! Kind regards Steve Bellow Is a list of what my wife and I have done in the last few years incase anyone is interested!:- Removal of chimney breast (quoted £3k) Twinwall and Flexi flue install (quoted £3k, including £300 to make a stud frame and plasterboard in the flue) Demolishing of existing kitchen. Dug footings (along with a man with a digger) We did the concrete footings pour and 6x5m concrete slab. Installed structural steels. We build a 6x5m mono pitch roof (fibreglassed, waiting to be slated). Built and slated front porch roof. Concrete footings pour 5x5m Currently building 5x5m hip to gable roof. Currently building 3x W40 Crittal style french doors. (We can see why they charge £25k!)