Dreadnaught

Intriguing design. Will it be a bungalow? What type of roof (flat or pitched)? Have you considered roof windows?

I am a fan of flexibility, having options, and for simplicity. When I build my new house I plan to include the wiring and pipes for both an ASHP and gas boiler. To go with the ASHP, I will also include UFH piping in my reinforced concrete raft foundation. Installing all the options at the time of the build costs peanuts. But how about adding one more cheap option: from a capital cost perspective, the cheapest of all. When I pour my my raft foundation, why don't I also include some electrical heating wire too embedded deep within the concrete? From checking on eBay, the cost of loose heating wire seems to be about £150 for 2kW. £150 really is peanuts! And it beats even a Willis heater for simplicity. Wet UFH after all needs a manifold, a pump, regulators, etc. While I would still have all the other options available later, I could use the wire heating for the first couple of years while I learn how my new house responds. What does everyone think? Bad idea?

There is a body of evidence that being colder prior to retiring to bed promotes sleep.

I don't know if this will be much help, but I have just ordered my rooflights for my forthcoming build and here are the cross-sections and installation instructions for them. I might give you some insight and thoughts about your own rooflight problems: https://roof-maker.co.uk/rooflights/flat-rooflights/fixed-flat-rooflights/

I wonder why did you want a stiffer roof, will you be regularly walking on it?

UFH guidance gives a Tog limit for the carpet insulative power. I have seen the figure 2.5 Tog used regularly in this regard. (It should be Tog total of both the carpet and its underlay.)

Fabric-first approach: I would go for 100mm of insulation. In my opinion, it is as much about internal comfort as anything to do with energy loss. The higher level of insulation will provide a marginal improvement in the uniformity and stability of the temperature within your home. And the marginally warmer walls will marginally improve the infra-red emittance, so giving a feeling of warmth. As @Ed Davies mentioned recently in another post, your feeling of warmth comes approximately half from the air temperature but half from the invisible heat-glow from the surfaces around you (I have simplified quite a lot but you get the point). That is why I would go for 100mm insulation. If you have ever been inside a full passive house, that feeling of comfort comes from a combination of: (i) the stability and uniformity of the internal climate (which for example extinguishes drafts); and (ii) the invisible heat-glow from the walls. Just my opinions.

A few observations from a layman: - Would a single downpipe be sufficient for a roof, especially your large roof section; or prone to a single blockage causing flooding? - Do you actually need the parapet to surround all of the roofs? For parts that may not be visible to you, you could leave out the parapet and instead have run-off directly from the roof into a gutter. I will have this on two full sides of my flat roof: a greatly reduced risk of a drain pipe blockage being acutely problematic. - [Minor] Doesn't coping have a drip feature on both edges? As to your Warm roof, to me that looks like a hybrid roof with (PIR) insulation above the structural joists (a warm roof) but also between the joists (a cold roof). If it were me I would be wanting a dew-point analysis (WUFI analysis) on that to insure against interstitial condensation, as you do not have any form of ventilation for the lower layer of insulation. And this is relevant for the section of you highlight in red. In that area, in the depths of winter, that part of the insulation between the joists immediately beneath the red section will be colder, with the concomitant risk of interstitial condensation forming particularly there. That would concern me. Edited to add: no service void for your ceiling?

@Home Farm, well said! Hope it goes well for you. Everyone needs to start somewhere. I wonder, will you be making videos or passing on tips? I'd be keen to learn as you learn.

I wonder what a noise assessment for an ASHP looks like?

Sorry to resurrect a three-year-old thread. @swisscheese I wonder how did you resolve this issue with the LPA (presumably Cambridge City Council)? Did you DIY install your ASHP in the end, despite your neighbour? This is relevant for me because I might have an ASHP for my build in Cambridge.

Don't forget the UFH tubing can also be used for cooling as well as heating. Give how cheap it is to include it, perhaps that could a motivation to install it even if heating is not anticipated?

In my case, I found that the local structural engineering firm had one (relatively junior) engineer in the firm who specialised in SUDS and was able to do my SUDS designs and calculations that satisfied the planners. A general mid-sized engineering firm near you might have the same. As it turned out, using them was one of the biggest mistakes so far with my build, not because of their work but because of their approach and attitude, but that's quite another story. Also, I don't think its relevant for you, but in my case I subsequently learnt that the manufacturer of the system I was intending to use (in my case a green roof) would happily provide SUDS designs and calculations free-of-charge (so long as I also bought their products) and I wish I had used them from the start.

Zero missing? "OPTIM-R E panels achieve a declared thermal conductivity of 0.009 W/m·K", source.

@anonfool77, welcome to the forum. I can't offer any advice but thanks for sharing that list. I will be looking into getting one of these warranties for my forthcoming build (even while knowing that they are all quite useless). And your list is a good starting point for me. Good luck finding a solution for your problem. Personally, I would be tempted to ask the seller to arrange a retrospective warranty so that the sale can go through.

I am about a month behind the schedule in my mind. My signing-up with a timber-frame company was delayed as my favoured company moved their factory over Christmas. In the end I seriously considered no less than seven frame companies, met with five, and visited the factories of four. I have now chosen the company and will be signing on the dotted line soon. It is a local Cambridgeshire firm and represented for me the best balance between cost, their approach, and the personalities involved. Observations from the last month: Old Buildhub searches work well. I have text shortcut the throws the following in to a google search: "site:buildhub.org.uk". That enables effortless searching of the Buildhub archive for any string. For example, when thinking about which SE to use to design my slab, I threw "site:buildhub.org.uk Tanner" into Google a re-read the posts by @Alexphd1, @Triassic, @RichC and others, some of which were years old, arranged a call with Hilliard himself in Ireland, and all my problems went away. Same applied for bolstering my list of raft installers and a host of other subjects besides. I looked again at the make-up of my roof and foundations. My dwelling has a ridge height limit in its deeds and I want high, 3m, ceilings. I went around the houses on both subjects (thanks to you all for your contributions to my threads on the subjects). On the roof I ended up somewhere new, and flipped form a cold to a warm room, and saved about 200mm. On the floor, I ended up back where I started, with an insulated concrete raft attached to screw piles but, with the help of Hilliard Tanner, it will be a thinner 100mm raft, with strengthening ribs, and a 200mm ring beam. Because the raft will be tied-in to the screw piles the insulation beneath will not be load bearing. This means that PIR will work just as well as EPS as insulation. PIR is thinner for a given U-value so once again I will be saving about 200mm of thickness. Resolving the issues the ridge and front-door-threshold heights then enabled me dive deeply in to the levels. I have a small but complex plot and deciding levels took quite some head-scratching, especially as my site is supposedly "no-dig" because of previous tree roots. Levels are now done I think. With all the fundamental decisions about the build now resolved, the cavalcade of actions leading up to the start on site can now begin in earnest: frame design, engineering inputs, construction drawings; planning-conditions discharge (and maybe non-material amendment); tenders for groundworkers, screw-pile suppliers and installers, raft makers, rooflights, windows; site insurance, building control, warranty. Oh, and I have re-designed the façade once again. All systems go! Spirits are high.

Thanks @Dan Feist. Are you intending to buy one yourself? I wonder, how does one read "A+7/W35kW"; I am guessing "A" is air temperature and "W" is water temperature? I am following this closely as this as potentially ideal solution for my forthcoming build, combined with a SunAmp. Interestingly, R290 seems to be simply just propane gas (!) (CH3CH2CH3) but it has a desirably "low Global Warming Potential". I believe that a qualified and therefore expensive gas-fitter is not required for installation.

Did it. Skipped lots of the questions. It all helps, hopefully.

Welcome @Dpirie76. Suffolk is a beautiful county. I'm just across the border in Cambridge. I don't know any other Suffolk-based members on here but there are few of us in neighbouring counties.

Welcome. You're just south of me, I'm in Cambridge.

An impressive piece of draftsmanship!

@Nickfromwales: https://www.imore.com/best-homekit-humidity-sensors

I have embraced the Philips Hue smart lighting, especially the "white ambient" bulbs. Pricey I know but the "temperature" of the white light is tuneable.

Thanks @Archer. I hadn't seen Quickbase. Had a quick look. Says "lightweight foundation system for conservatories and lightweight structures". I will drop them a line to see what "lightweight" means.

Thanks @Archer. By coincidence yes I did notice that system this very weekend when doing some google searching. Yesterday, I sent them an email enquiring for more details.