TerryE

We are talking of a 100% variance in use here. Most water meters will measure down to 10ltr units. Turn off the internal stopcock; wait 30 mins and reread. The meter shouldn't have moved. Turn on the cock but make sure no one flushes loos etc for 30 mins and repeat. Turn it on again and draw off 50ltr using a bucket at the outside tap and reread. This binary chop should be enough to give you a good idea of where the issue is.

You would also be better using a hot+cold fill washing machine and dishwasher, but even 12 kWh / day is not to be sneezed at. With PV + micro hydro + battery, the number of times that you'd need to fall back to using a generator would be very small.

Yup, the main thing that you want is a reasonable spatial separation with the two vents on the same flow surface. The spatial separation just needs to be enough to stop any material recirculation. Using the same flow surface mitigates the pumping effects of high wind.

I take a slightly different view to Jeremy in that I am happy to use the phrase thermal mass as an informal description of a general property, though when it comes to actual modelling the thermal performance of a house, you'll actually use the more precisely defined coefficients of thermal capacity, specific heat, conductivity, etc. We will never have a near energy neutral house, mainly because our planners discouraged / forbade our use of PV, and severely limited our window dimensions, so we have little scope for large solar gain in winter. But then again I think that solar gain is very much a two edged sword, and overall I'm glad we don't have a large area of glass: what most seem to forget is that an energy efficient house is pretty much energy neutral for 3 season a year, and that solar gain during the seasons can be a real cause of severe overheating, unless you put a lot of effort into the design to avoid this.

We used up-and-over wall units above our work surfaces and we think that they work well. A variant of what @cherryfountain suggests we used a local Wickes kitchen designer face-to-face, and he did a very good job. Their configuration software makes sure that you order all of the right bits and pieces. They also supplied everything and at a competitive price. We also tried a more up-market company, but went with Wickes in the end. I suspect there is little to choose between any of the budget kitchen providers. As far as I know everyone uses the same suppliers for carcasses hinge furniture, etc. So there is little to choose between them, I feel. The main variant in terms of quality is the kitchen fitters, and in our case we fitted the kitchen ourselves so that wasn't an issue: I am a pretty good woodworker and very fastidious, so we knew we would get the fitting that we would want.

We did a lot of trades ourselves in our selfbuild. Doing the MVHR was one of the simplest, I feel. I did the basic design myself and sent the stuff to Gary at BPC, who confirmed that the design was fine and he gave us a complete parts list that we would need; we then ordered everything from him: BPC get another recommendation from us. Semi-rigid 75mm pipe work is easy to deploy in Posi-joists so long as there are two of you working together, and yes you will need to double up some runs such as the kitchen and any longer runs. We've had the system running for over a year now with absolutely no problems, and now that the build has been signed off like others we are thinking of dialling back the flow rate slightly. We placed our plenum manifold chambers in a small cupboard off or landing -- a nice central location adjacent to the room where the MVHR unit itself was positioned -- so that the runs work pretty balanced. Planning out the "Clapham Junction" into the plenums was fun. If you can then space out the inlet and outlet on the same wall about 4m apart or more. Having them on the same wall minimises wind gusting effects. Also make sure to install your foulwater pipework and MVHR ducting before the plumber and the electrician get to work. They can work around 75mm ducting but not v.v.

Another couple who use the forum recently came to visit our house and to discuss issues and ideas. One comment they made was that the whole issue of choosing a TF and evaluating various quotes was very much an "apples and oranges" comparison. You need to discus very carefully with putative suppliers what is in scope of supply and what is not, and have a clear shared understanding of who is responsible for what. Our slab and TF ended up as about 25% of our total build cost. (By way of comparison, we also had to have a local stone skin on our house; this looks beautiful, but this also ended up costing more than the supply and build of the slab, TF, insulation and certified airtightness.) One of the reasons that I feel the the PHPP is total overkill is that the simple calculation method that Jeremy, I and many others used is that it gives an answer accurate to 10% or so and is transparent enough to allow you to do and understand the various design trade-offs. IMO, the major risk / error here is between the nominal as-designed, and the actual as-built. One of the reasons that we finally chose a TF twinwall / passive slab approach (even though this was slight more expensive and 100mm deeper profile than U-value equivalent single frame approaches is that this pump cellulose approach and the corresponding wall profile are very airtight by design and has very low associated Ψ values, to the point that the supplier contracts to deliver to a U-value and airtightness specification. This gave us a high degree of confidence that the as-build performance would be as designed.

+1 with Jeremy and Dave's comment. Our basic layout is a 3 × 2 block layout. The front centre block is an open hall which rises up all 3 stories. The ground floor left and right are a through living room and kitchen diner. We leave the lounge and kitchen doors open at night, so the UFH heated air also flows upstairs. (The central hall also has an opening roof light on the top floor, which gives us excellent summer cooling: open this and a window or two on the shaded side of the build dumps excess heat in the house.) Karen, I think that your emphasis here is wrong. The design heat losses in a build are in essence very simple: a set of surfaces with known area, U-value and delta T; an air change rate with given % heat recovery and specific heat. With a well designed house, the thermal bridging and linear psi components are minimal. So the heat demand for a given outside temp would be well determined. If your house is losing 40 kWh/day at the target internal temperature, then you can maintain overall heat balance with a single 2kW oil heater or a 5kW ASHP on a 3 CoP at a 30% duty cycle even at a 30% output. If your as-built house is losing 120 kWh / day instead of a designed 40, this isn't the fault of the ASHP, it is because of design flaws or poor quality control during construction. I could understand and accept a 20% as-built variance, but much more than that is just crap workmanship, IMO. Fixing it is more one of understanding and mitigating these built flaws.

It's about 21½°C throughout our upstairs in our house and 22½°C downstairs, so "no heat at all upstairs" definitely can work with a correctly designed and built energy-efficient house. On Jude's original post we actually use slightly more than this in this weather in a smaller house (4 double bedrooms) than Jude's. However, about 75% of our use is at E7 cheap rate, which mitigates this cost. We also haven't got an ASHP installed yet, so our heating is at a CoP of 1 rather than 3-4. 1300kWh suggests to me that the heating element is probably more than 1000kWh + at a CoP of 3 say means that the house is leaking about 100+ kWh of heat / day. Something is wrong with the as-built performance of Jude's house.

What I find interesting about the FIR images in the Guardian article is that -- to me at least -- they underline the whole issue of where the air tightness is achieved if at all: you can have a airtight(ish) living space but if there is free convective circulation within the dot-and-dab (or service) voids interchanging with external air, then this can act as an active heat pump dumping heat out of the house. The airtightness should be achieved and verified before boarding out.

If you really feel that the light and view are what you want then go for it. My caveat would be to reiterate that this will still complicate thermal management that you should actively address in your design to mitigate the living environment issues: You will have an area of approaching 25m² of glass at a U-value of perhaps 0.8 that will give an additional ~400W heat loss in winter so you will need some form of in-room heating (a radiator or room-specific UFH zone) to keep the room comfortable for about 6 months a year. On a sunny spring / autumn day (low elevation sun) you could be getting up to 10kW of solar gain through the windows if you want unfiltered natural light. No space built even to minimum compliance with current BRegs can take this sort of heat. High-reflective glass can mitigate this up to 5×, but this could destroy that "natural light" feel. External shuttering is there for a reason in most Mediterranean homes. The other alternative is some form of forced air exchange / cooling, but 10kW is a heavy load. Whatever you do, you will need to manage the thermal environment actively if you don't want the room to get into the 30s and even 40s °C. Thanks for this. Nice to hear. BTW, we will be putting out an upgrade for SDK3.0 which means that the Lua application programmer will have 57kB available RAM as well as the up to 256Kb Lua program space offered by LFS. Not bad for a £2 chip

This is the sort of frill that architects love, but that you will find a total PITA when you actually come to live in the house. It will add a lot to the cost of the build, the complexity of the structural engineering and the thermal management of the lived-in environment. Think of a number in the region of £30K+ and ask yourself: is it really worth spending that sort of cost to be able to look out of the corner of the room -- including whilst lying on the floor or standing on a step ladder.

You need a means of escape for every living room. This is either a direct exit from the room or a 30 minute rated safety corridor. You seem to have neither, so I strongly advise you appoint an commercial Building Control company (JHAI or the like) and discuss this in detail with your allocated officer before you finalise the design. You've got a lot of glass and bifolds = lots of heat losses in winter; poor airtighness; major issues with cooling for the rest of the year on sunny days. Embedding decent thermal performance into your build is going to be a major challenge for you.

"Non-material" means that it is automatically fully delegated to the development group in the Planning Dept. They aren't even passed to the planning committee. However, the determination of "non-materiality" is also fully delegated so the planning officer can decided "this is not a non-material change". This is in effect a proforma refusal and processing this refusal will take him or her maybe 10-15 mins. Fee collected. Job done. And your only option is now to resubmit as a MMA, knowing that it has already been turned down as non-material. In our case I suggested to our Enforcement Officer that I contact our allocated Planning Officer and discuss the issue with him. Our EO then emailed me and told me not to contact our previously allocated PO as the current practice is to allocate cases on a load basis; the PO would contact me. Well, that is true, I was contacted, but with the application refusal, and no right of input or appeal (as you can't appeal a fully delegated decision). Long gone are the days when you could ring up your PO and discuss the application with him or her before submitting it. The only consultation mechanism our LPA offers is what is known as pre-planning advice (which you have to pay for and which takes 6 weeks), but you can't use PPA to prepare for an NMA -- Catch-22.

You need to check carefully on your LPA current policy on NMAs. We had an issue during our build where planning EO told us to put in an NMA, but the planning development then turned it down. Some LPAs discourage NMAs because they don't recover enough on the fee scales to make it worth their while.

@RandAbuild, (we can chat about this this PM ) We also have a Vent Axia Kinetic Plus, and vacuum out the filters every 3 months and did our first annual service about 3 months ago. It was all pretty clean inside. But I can see Jack's point. Give the bacteria some standing water and warmth and somehow they'll fine a way to make a living out of the air particulates. @jack, thanks for the warning. This all reminds me of a report on a set of MVHR installed in a build of community housing. Over half were incorrectly installed (IIRC, half were installed back-to-front) and only one in the entire community was being regularly maintained and used correctly.

Import electricity from Morocco instead of NGas from Russia.

Yes it will help, but demand shaping and demand levelling through storage will only enable us to drop our peak capacity by maybe 30% . This will in turn allow us to retire a lot of old, polluting generation capacity. However, even if we do this, then we still need to meet the base load in the "sun doesn't shine; the wind doesn't blow" cases.

What do you do if you have a calm few days in winter? Demand-side shaping is essential. Solving the base-load problem is essential. This isn't like developing nuclear fusion, as there are no fundamental physics issues to solve; more just the sort of WW2 technology problem -- lots of smaller incremental advances and scaling of engineering and production. This is eminently solvable, but its just a matter of political will and priority, and these are sadly lacking in the western world.

Grid scale storage is an essential element to the mix. Whilst the Li-based approaches mentioned by @jack above are an important stepping stone, I just don't think that the 1850-class cells are a sensible storage atom for grid-scale storage. Hopefully the liquid metal technologies evangelised by Professor Sadoway et al will come on stream in the next 5 years because these will both drop the unit price by perhaps 5× and have a usable working life in the 20+ years range. As Sadoway points out, the energy grid is currently a zero inventory system -- by far the largest zero inventory system in the world. We also need to have adaptive demand strategies down to the consumer level, IMO. I am pretty flexible where in the day I buy my power -- or at least over 70% of it -- but I would like to buy it at the cheepest price.

I really do wonder why it is still popular to include a garage within the fabric of the house. If you price out the cost per m², then this is bloody expensive off-road parking -- especially as most people end up using it as an inefficiently laid out glory hole because of the hassle of getting a modern-sized car into a standard garage opening. This is especially in your case where the turning circle for access doesn't even comply with highways guidelines. My advice is to lose the garage and use the space for something more functional. Modern cars don't really need garaging in the UK; using decent powered gates can provide secure and a lot more cost-effective off-street parking. As @Weebles suggests: really consider losing the split levels. These are a real PITA for construction and will add to costs. Also a big downer in terms of mobility access. Yes, your site has a gradient, but any competent architect should be able to do the cut and fill calcs so that you can level the site at least covering the foundation area and parking. (Extend this level area in front of the kitchen. Even if you don't want to park here regularly, having this as overspill when friends and family are using BR 2 and 3 is really useful.) This amount of moving soil and levelling within the site is cheap -- and a lot cheaper in terms of overall build costs. It only starts to become expensive if you have to move a lot of soil and subsoil off site. I see that you have a "wood store". Why? If you are planning a wood-stove then where are you going to fit it? Your plans don't seem to facilitate one, or is that what is shown in the living room? Wood stoves are very fashionable but IMO totally impractical for a new build conforming to decent build standards. The minimum practical output of a wood-stove on tickover is about 3 kW. This will rapidly overheat a room the size of your sitting room even if you are attempting to build to minimum compliance to current BRegs. You or your architect need to do the heat calcs and consider the implications. Also search this forum, as there are many topics discussing the pros and mostly cons of using a wood-stove.

Just to endorse what Jeremy is saying, IMO the key difference in my build was that the build was airtight by design rather that by construction fix-up. Examples here are: On each floor the joists were hung off the TF panels, decked out and the next floor on panels sat on this decking. There was a air tightness membrane wrap from the inside lower panel, out and over the joist ends and back inside and up the upper panel. This sealed all joist ends for air tightness, so no taping up around joist ends. All other interfaces were properly taped and sealed by the MBC airtightness crew. None of my trades were allowed to penetrate the filled panels. Where penetrations were require Jan and I had a standard procedure for fittting an airtight access pipe: drill through inside to out with a 1m × 15mm drill; use this hole to core out the 25mm (say) entry and exit holes; feed through the 25mm abs pipe and seal properly at both ends; one of us then insulated and sealed the inner pipe bore when the electrician (or whoever) was done. Our biggest residual leak by far, IMO was down to incorrect sealing in fenestration, which is fairly easy to identify and fix. One issue that we did avoid -- thanks to reading Jeremy's early posts on this -- was to place our inlet and outlet some 5m apart high on the same gable wall so we don't seem to get the gust pumping effect that some installations experience, as any wind-gusting impacts the inlet and outlet equally.

I sent the test report to my B Insp and he was really happy with it. The requirement is 10 and I think 14× better or thereabouts is a reasonable margin. Don't you?

Good. You understood what I was trying to explain. Jan read it and said that I was clear as mud. ?

Put a small horizontal rafters bridging across between the pitched rafters leaving at least 100mm between the top and the ridge beam. You can now insert 50mm Celotex flush with the base of the rafter leaving a 50mm up-and-over airgap under the breather membrane. And add another 75mm celotex bonded plasterboard or equiv across the rafters. Note that you really need to dry line the room with 50 or 75 mm Celotex bonded plasterboard as well to get acceptable thermal performance. Nowhere near passive, but at least not bloody freezing in winter.