Iceverge

Grohe Tempesta 100 I think our shower tray may be a contributing factor too. It's the same as this one. One like @dpmiller has that is designed for an open screen is probably better.

We have two 900x1400 showers. An en-suite one with a 900 mm screen and a 300mm hinged deflector and the other with a conventional sliding 650mm door +650mm fixed. With the sliding door I put the shower rail and head on the long wall. It’s a far more spacious experience with all the extra elbow room compared to the one where your back is to the shorter wall. The en-suite does tend to let a puddle of water flow out unless you have the shower head quite vertical too.

I looked at theirs, in fact I bought some upvc for the garage. They are used by 90%+ of the houses near me as they are localish and cheap. However I didn't even get a quote for the house. Whilst the profiles themselves are ok, the metalwork and the air sealing leaves a lot to be desired. I have lived in a couple of houses with their double glazing units and the hinges and locks just don't last. The T&T unit in the showroom had fallen off the hinges. The saleswoman had no notion of the G-Value, Frame u value, glass u value etc, just that they were meaninglessly "A-rated". I think little compares to going to see windows that have been installed with 5-10 years +. Find someone who has already got them and pay a visit. I did that with mine (Veka Softline 82) The sashes all air sealed and clicked into place like they did when they were new. Of course the profile is only part of the equation. The frame reinforcement, manufacturing quality, ironware, latches and locks , and of course installation count for a huge amount. If you can find a provider that has worked on passivhaus certified projects and quiz them on the technicalities and receive satisfactory answers you will be onto a winner.

We went on hols for a week and I monitored the energy use in our absence. Our house is all electric. Passive class, no heat pumps or woodburner. I turned off everything except the following. MVHR ,Fridge/Freezer ,Biocycle septic tank. Total 3.68 kWh/day. (153 watts) Heat Loss from the immersion powered 300l UVC @70deg. 1.64 kWh/day (68 watts equivalent load) Total background load 221 Watts or 5.3kWh/day of which 30% is heat loss from the cylinder. Granted everything except the septic tank is inside the heated envelope so it contributes to the heat load for the 3-4 months of the year it's needed. Our daily electricity use is 20kWh of which normal use is about 11kWh DHW (including tank heat loss) 3.68 kWh background load and 5.32 kWh everything else. I reckon we could half our electricity use with a few straightforward steps. Burn something ( wood/oil/gas/diesel) to heat water and provide space heating. Replace the tumble dryer with an MVHR vented drying cupboard. Hot fill washing machine and dishwashers. Fill the kettle from the hot tap. That would leave a conservative 3kWh/day electricity demand with 153w base load. I considered what if our house was where yours was in Scotland with a 15kW array and a 20kWh battery storage system. ( Best installed price I reckon would be about £30,000) According to PVGIS you would still be short for about 1/4 of the days in december. You would have to make further lifestyle compromises like cooking on solid fuel, restricting appliance use etc during the winter. An electric vehicle would be out of the question Nov- Feb. If you were to consider the same case in Brighton, with a 12kW array and a 7kWh battery you would short less than 7 days a year. I think in your situation the electricity connection is your only option unless you want to live a country lifestyle of 100 years ago. Perhaps consider your petrol cost saved by changing to an electric vehicle as part of the equation when getting a grid connection.

Passive certified UPVC for us with top notch ironmongery. €15000 €37500 for aluclad of equilivant performance. The trick is finding upvc that’s not poor quality.

@pdf27 An excellent post. I will dissect the full PDF later One point I would caution though with this is they had their array at 10deg (due to architectural/planning constraints I assume). If they were able to mount them at 75deg they would have been much more optimum for winter production. Annual production would have only dropped slightly 10.9MWh to 10.4 but their December production would have doubled from 237kWh to 487kWh.

We use 20kWh per day but that’s heating water for 4 , boiling the kettle regularly, electric cooking, constantly running biocycle unit, tumble dryer, constantly running MVHR, and powering a borehole pump. Yet to see what that escalates to with the winter. My parents live in a drafty house next door with literally no insulation. Everyday the rayburn cooker is lit. It heats the water, boils the kettle, cooks dinner, heats the house, dries the clothes and, by stack effect, ventilates the house. Old fashioned septic tank. They do have an electric shower. They use about 10kg per day of dried oak in the summer. (roughly 50kWh) Our electricity use is double theirs although their energy use is triple ours. Probably at least 10 times to achieve the same comfort levels. You can go off grid easily if you are willing to cook, heat and DHW on Wood/gas/oil. It won’t be the freewheeling energy on tap lifestyle that most of us rightly or wrongly enjoy however.

Yup. It's required with a ventilated cold roof AFAIK

You should have a thermostatic mixing valve (TMV) to prevent this in any case if you are planning on storing water much above 50deg. Like you say scalding isn't nice. You've lost me. I was assuming a standard vertical tank throughout. It is. There was 130 Litres sitting in the pipe outside your house at 10 deg and now there's magically 130 litres at 40 deg in your bathtub.

I've boiled (lol) it down to the above rough formula.

The sums aren't too involved. Lets look at the heat loss from the cylinder first. I reckon that the average temperature of an UVC is 30 deg when you stop getting useful hot water out of the tap. It'll obviously be higher at the top of the tank and lower and the bottom. Formula for heat energy stored in water is ( temp difference before and after) X (4.2) X ( kg of water) = Energy in kJ. Take stored water at 70 deg and a 300l ( also 300kg) tank. 70-30 = (40 deg difference X 4.2 X 300kg ) = 50400kJ Divide by 3600 for kWh = 14 kWh of energy stored. Now if you have a 400l tank at 60 deg 60- 30 deg =30deg temp difference 30 X 4.2 X 400L = 50400kJ = 14 kWh. Exactly the same useful stored energy. Take the two cylinders at a surface area of 2.82m2 and 3.35m2 Multiply an assumed u value of 0.5 for both X ( temp difference to room at 20deg) * Surface area = heat loss in Watts. for the 300l 0.5X50x2.93 = 73 Watts for the 400l 0.5X40X3.44 =69 Watts Less energy lost by the larger tank as the decreased temperature more than compensates for the increased surface area. Now if you want a 130l bath at 40 deg. Your incoming water temp is 10 deg. Effectively you need to get the energy equivalent of heating 130l X 30 deg out of your tank or 130l X 30deg x 4.2 /3600 or 4.55 kWh of energy. As your 300l tank at 70 Deg stores 14kWh you could get 3 Baths before you had used all the hot water. However if you opt for the 400l tank and turn it up to 70 Deg you have 18.7kWh or 4 baths. In short. with the bigger tank you have the choice of storing more energy or having less energy losses for the equivalent energy stored.

Ah, I was talking about blown cellulose, mineral wool and woodfiber.

Are you referring to the boric acid additive in cellulose Vs metal? Any references on this for my perusal?

Welcome. Keep it small and simple. The closer to a box the better. Avoid unusual techniques and materials. Don't underestimate the amount of work required, things take 3 times as long as you think. Above all, enjoy it and best of luck.

What stage of the build are you at? If it is before roofing membrane I would just fit the insulation roll ensuring continuity of insulation walls to roof and then fit the rafter roll and then the membrane. It's difficult to ensure theres no gap between the wall and the roof batts otherwise. Have you discounted blown in insulation?

As @IanR said just get the biggest one you practically can. You'll have lower losses and the boiler will be less prone to cycling. We have a 300l immersion heated to 65-70deg overnight ( cheap electricity) with very similar usage patterns to yourself and it's fine with no daytime topup. You have the option for day heat also so i reckon anything north of 200l will be fine.

I considered it but decided you didn't need it. It's unlikely your VCL will be perfect in any case. Certainly not if you plan to fix plasterboard directly up underneath it as guys can play fast and loose with the screw gun. You're unlikely to have many penetrations in the plasterboard also. I'd save myself the hassle, sealant and paint will be fine.

For what it is, you're never going to have an exceptionally well insulated garage. The garage door will not be anything near airtight so it'll never be warm. I assume you have no floor insulation? I see your main aim as keeping condensation at bay and providing some level of frost protection. For the roof make sure you build something that won't rot. Warm roofs are generally safer in this regard but cold ones can work too provided you don't trap moisture in the structure. In your case I would build: Roof final covering Ply Roof furring strips for slope 50mm min gap between joists above the insulation. Every single cavity well ventilated to the outside via the eves Ideally at opposite sides of the building. Include some insect mesh here to keep the creepys out. 150mm earthwool push fitted between the joists . It's very cheap and more is no harm as you'll loose some of the insulative value due to thermal bypass. You can use netting or waste plastic strapping stapled to hold it in place. Plasterboard taped and skimmed at the joints. Use a flexible sealant to join it to the wall and seal the few penetrations in the plasterboard well. This will be enough to prevent bulk air movement taking moisture into your rafters. I would fit through the wall ventilation in the wall opposite the garage door to ensure the humidity didn't rise to unacceptable levels inside. Put them somewhere they won't get obstructed. As for the MVHR. Best practice is to have it within the thermal envelope of the house. If this is not an option I would build an insulated box for it to at least the same standard as the house. Make it accessible for servicing. Don't forget about the condensate drain and consider that this will freeze if not protected. For the walls, I would lean toward S&C. More airtight, firmer to fix into, probably just as cheap as you're rendering externally anyway. If you use plasterboard I would omit the vapour barrier. It will cause more problems than solve them. It'll be full of holes anyway as you'll have to mechanically fix through it.

@Tom What a bunch of clowns. I think you need to get rid. It might take a few weeks of waiting to get someone competent but this kind of fiasco will cost you more time in remedying the situation later. Take plenty of photos of the mess they've caused. Not necessarily for punitive action against them but rather to show you're not an unreasonable client to the next builders, just one who expects good standards.

You might have to look into getting ties. I got mine from http://www.vartryengineering.com/products/extra-long-wall-tie-large-cavities.html via a builders merchant here in Ireland. I don't know if they'll supply the UK. Yup. Sounds good. K rend is normally either/or as i understand it. One option I didn't consider was getting coloured sand and cement. A friend did their's in white and it looks painted. It cost only about €7-800 extra in materials over normal sand/cement. It did require a nap finish though to waterproof it.

@Moonshine U values are indeed not stellar. It's the frame U value rather than the glazing that's the issue. Unsurprisingly it's the smallest windows that have the most frame area vs glass that are the worst. Here is a screenshot of my PHPP to give an idea of what range of frame U values are normal.

Is the insulation on the level or on the slope? Can you not just use some appropriate expanding foam to mend the holes? Wires should be ok. We put 450mm cellulose over ours. ( BTW i'm not an electrician so beware my advice)

@Tom You have my sympathy. It's a rubbish situation to be in. It sounds like you're in need of a more conventional builder. Get some solid detailed plans ready, get in touch with as many of them as you can. Get good references. Pick the best and sign a contract. However you'll have to wait for the good guys and you'll have to pay them. The current bunch probably aren't bad guys. Just a bit boyscoutish. Unwilling to commit to a proper contract. Unable to cost a project properly, and include rates for plant hire etc. Unable to straightforwardly say they've underpriced the project, take the hit on works to date and up the rates for the remainder. Out of interest what factors swing you towards the current builders? Time/cost?

I like it. Can you provision for a ground floor shower or a lift for less mobile occupants. Privacy in the snug might be compromised from the kitchen with the the glazing arrangement. Have you considered overheating with the large ESE window in the kitchen? Expensive and some tricky details, yup, but if you're prepared these can be hurdled. Looking forward to seeing your progress.

What is your exact wall build up at present on site? Are you planning on removing existing cladding? Passive buildings are a wholistic concept. Super insulating your structure is not a panacea. Airtightness, appropriate glazing and shading are all important. Neglecting anyone and you’ll have an underperforming building.