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In my experience Building control are generally far more helpful than planning. Planning messed me about for over a year and then agreed my original proposal (long story). Building Control allowed me to get away with a window that was slightly too narrow and another with the sill slightly too low when it would have been difficult to fix either.

As I remember Approved Document Part A basically says... "If you build it like this it will meet the Building Regulations". However you are free to build anything you like if you can convince Building Control that it also meets the Building Regulations. So I see no problem with having higher ceilings provided Building Control are happy. To do that they may want evidence that someone like a structural engineer has approved the design. I would just ask them if what you propose is ok.

The kitchen/utility is going to be used regularly so I would feed it from the UVC to take advantage of the ASHP COP. If it's a long way from the UVC I would install a well insulated secondary loop so hot water comes through instantly. If the downstairs shower is going to get used regularly I would also feed it DHW from the UVC (also with secondary loop for same reason). I'm not sure about using an instant water heater for the downstairs shower and basin. What sort of flow rate do you want? Personally I like a high flow rate shower and for that you need quite a powerful unit - perhaps 10-12kW although some people are happy with 7-8kW showers. How much PV are you installing? If it was only 4KW you would be importing the rest when using this shower. Would be interested in Nicks views on this? PS Size the ASHP and UVC correctly you shouldn't run out of DHW. We just have a 300L TS and haven't run out although it is recharged fairly quickly by our boiler.

Perhaps dab some silicon bath sealer around the screw terminal to keep moisture out (after testing it works!)

That's interesting. So it would look something like this if I've understood correctly.... DHW Primary (Presurised): ASHP -> TS -> UVC Stove -> UVC (Dump rad and PRV) Secondary(Mains pressure): Cold incoming -> Coil in TS -> Coil in UVC -> DHW (Mains pressure) UFH/CH ASHP -> TS -> UFH (Presurised) PV PV -> UVC This would mean the TS pre-warms the water on it's way through to the UVC when a tap/shower is opened). TS runs at UFH temperatures so no issues with the temperature uplift (Good ASHP COP). The TS and UVC and UFH are all unvented/pressurised and can be dosed with Fernox and something to stop legionaries if deemed necessary. . The stove heats the DHW but not the UFH. The UVC would/could be 300L-500L and the TS perhaps only 100L ? Have I understood all that Nick?

Yes that works. Think it's fairly I think that what I was suggesting just above.

I grew up in a house that used a wood/coal burner with back boiler. My parents were more than happy to see the back of it when gas CH was installed. It's not the feeding with wood that gets to you its the emptying ash, cleaning of the glass, relighting etc. On balance I would install a stove (I like a real fire in winter) but I would ditch the idea of using the stove to heat the TS and install ASHP from the outset. The cost saving on the stove and the associated back boiler, plumbing and installation would help pay for the ASHP. There are other reasons for ditching the back boiler.. A new house will be well insulated that it will only be possible to run a small low output stove anyway. Are there many stoves that output little to the room and a lot to the back boiler? I've heard not. I would also want my stove room sealed so it burns outside air not room air. Again that reduces the number of options. Is there a low output stove that can hold enough wood to still be burning next day? How big will the PV system be? Is it worth using it to heat the house or would most of the benefit come from using excess to heat the DHW only? The heating won't be on in summer and excess PV output will be down in winter (more used for lighting). I think I'd be happy with just using the excess for DHW. Taken together (no back boiler and PV for DHW only) the result would be a much simpler system to install and operate......... . ASHP -> small buffer tank -> UFH ASHP -> Mains pressure DHW tank -> mixer -> DHW PV -> Element in Mains pressure DHW tank An off the shelf mains pressure DHW tank is also likely to be cheaper than a custom TS even though there isn't a huge difference in the parts count.

I think the idea is you drill holes in the wall. Fit Rawlplugs and then just tap/hammer the screws in (protecting the face of the switch with a block of wood/cloth). Not sure I like this idea. I'd buy another type that can be disassembled. You are bound to get some corrosion issue with the wire to the switch in a few years time and will need to take it apart to fix that.

DeeFunFan... My system is much less complicated (oil boiler -> Thermal Store -> DHW and UFH) yet I also had nightmare of a time finding a plumber that understood such a system. My builder recommended someone that claimed to be a retired heating engineer that acted as an expert witness in heating related legal cases. Even he didn't understand how this was meant to work. In the end I drove him 200 miles to visit a company that designed and sold thermal stores. They basically taught him/us how it should all work. The thermal store is the key to the system so I would go visit a few and have them make a proposal. +1 ASHP work best (highest COP) the lower the flow temperature. So they are ideal for UFH, less ideal for DHW. The approach Nick suggests is good but I'm not sure how/if it could be modified to allow the stove to heat the UFH. One possibility might be to have a very well stratified TS that is much hotter at the top than at the bottom (as le-cerveau mentioned) . The stove would heat the top and the ASHP would heat the middle/bottom. Both DHW and UFH would be drawn from around the middle. Little or no mixing down required although I would fit mixers anyway. However I think this would be a difficult system to set up and get working reliably. If the store wasn't perfectly stratified (eg it becomes stirred) then the ASHP flow temperature would have to be higher. You need to be really sure the TS company know what they are talking about and have them take you to see such a system in a customers house. We have two DHW outputs on our TS feeding different parts of the house. So two sets of plate heat exchangers, two pumps, two mixers, one secondary loop pump in addition to what's needed for the UFH. This works very well in that we get two mains pressure showers with good flow rates. However the heat loss from the TS and all that the additional plumbing is significant despite being insulated. The TS is in a room the size of a small bathroom and that room gets quite toasty. I would not want to waste that heat by having it leaking into the loft space. Plan an airing cupboard? PS: In case it's not obvious... I would NOT get your plumber to design this system. Get the TS company to do it and perhaps get your plumber to install it if you are happy with his work. PPS: There is an issue of who is responsible if it doesn't work. Is it down to the TS company to solve or the plumber or you?

I agree. Plan 1 first and anything else as a fall back.

I think it's also possible to have an above ground soakaway/soakaway mound. The idea being to put the water into a large bank of earth that distributes the water over it's footprint (which is much larger than a normal soakaway). Got a feeling someone on this forum has done one? or was it someone on The Green Building Forum? http://www.moir-environmental.co.uk/pdf/Mound Soakaways.pdf

No usually you have to do it or hire someone to do it. The BRE have a guide that explains how to design a soakaway and that includes some info on how to do the test.. http://forterra.co.uk/plugins/downloads/files/BRE365.pdf If you hire someone you get a report you can wave at the planners (to get a planning condition removed) and Building Control to keep them happy. You need a digger to make a few holes and it's common to get both a percolation test and a soil condition report done at the same time to save money. The latter may be needed for the foundation design as it includes info on load bearing capabilities, clay shrinkage etc. However if the soil in the are is well know/understood then you might get away without. May also need a water bowser to fill the hole for the percolation/infiltration test.

Has the current owner had a percolation test done to check drainage is as bad as suspected?

The simplest but most expensive option would be to employ an aborculturalist (tree surgeon) to do the work. Many councils will have a list of those they are familiar with although they may not recommended someone specifically. The aborculturalist can handle the Application to do the work on the trees including any "method statements" or specifications the tree officer may require. You can do it all yourself but an aborculturalist knows the language to use to keep the tree officer happy. Make sure the aborculturalist knows you have planning permission as I think the wording of that may mean permission isn't needed.

https://www.gov.uk/government/publications/vat-notice-708-buildings-and-construction/vat-notice-708-buildings-and-construction See para 2.1 for first time connections. Should be zero rated to you, (you cannot reclaim vat charged to you in error). Ask for requote pointing out this is a first connection for a new dwelling and quote VAT notice 708. I

Just for info, the notes on the reclaim form lists blinds under "Goods that you cannot claim for" .... "unless they are integral, that is, blinds inside sealed double glazed window units". However the list of what you can and cannot reclaim for is not intended to be definitive.

As I recall if the CU is more than 3m from the meter (tails longer than 3m) you must have a isolation switch/fuse in the meter cabinet. Have heard there are practical issues and issues of responsibility over who is responsible for installing that? Make sure your electrician is present when they come to install the meter so your man can install or move the switch/fuse if the meter installer is a "jobs worth" type.

Planners work in mysterious ways. Its quite possible they are/were personally happy with you building a three bedroom house of that size but needed to be able to claim that overall the department was/is meeting local demand for two bed houses. As others have said.. you don't need planning permission to divide a room in two or rename a home office into a bedroom later unless there is a specific planning condition attached to the grant that precludes this. Such conditions are rare. It's quite possible that by counting your build as a 2 bed rather that a 3 bed then the planning officer might have an easier time justifying a 4 bed up the road to the committee. Who knows. A lot of nonsense goes on and as long as you can build what you need it shouldn't matter. Just remember that dividing or renaming a room may have building control implications so they may need to be involved/informed even if the planners don't.

Just want to echo what others have said. Get the main surveyed for pressure and flow rate (these are different things) near the main as possible and at the house. Only with that data can you start thinking about solutions. If the static pressure is good but flow rate is poor then the an accumulator/bladder tank might be an option but don't rush that decision without data.

Pretty sure that will be fine.

When we had a main diverted it was included in the original bill/quote. As I remember the test involved putting chlorine in the pipe, waiting a few days, sampling the water, and sending it off for tests. If OK then they have to come back and turn on the water within a certain time period. The problem happens if they don't do all this within the prescribed timescale.. they have to start over. That's exactly what happened to us.

I suppose they might if you have paid for "pre-application advice". I suspect you will have to make an appointment to go see the paper planning file.

The CGT rules are pretty complicated. You will be aware there would be no CGT liability on any gain made while it's your Principle Private Residence. After that it gets tricky and you have options... For two years you can elect which house is your PPR even if you don't live in it. However you do need to make a formal election or the HMRC will decide which one based on where you actually live in. The other house (the one not elected as PPR) could potentially be liable for CGT on gains made during those two years. However it might not pay to elect the old house as PPR. That's because there is another rule that says something like.. As long as it's been lived in the last 18 months of your ownership it also counts as your PPR. If I've understood correctly it might pay to elect the new house as PPR and use this 18 month period for the old one. That way gains on both are exempt for 18 months? You should also investigate a capital gains tax break called Lettings Relief. This gives the owner of a rental property another allowance of up to £40,000 if the property being let has at some point been your PPR - which it has. Don't forget that the tax treatment of second homes can change (cgt, council tax and income tax could all change). It might change dramatically if Labor get in. You might want a clause in your contract with the new owners that allows you to bail on the deal. You wouldn't want to find yourself liable for greatly increased taxes and unable to increase the rent or sell up to get out of the situation.

I went with a 300L store. If building again I would go for bigger but we had issues fitting it through doorways. Specify extra insulation if you can.

Could you offer to collect the doors or is it a problem getting them to meet English standards?