Iceverge

On overheating I find South Windows are no issue as they're so easily shaded from the high summer midday sun. It's the West windows that are the real bugger. We have only about 4m2 of glazing to the west spread over 4 windows but they definitely cause the most discomfort. In the evening ( summer or winter) you'll have the effect of sun shining directly onto your skin making an otherwise comfortable room temp too hot. Ok if you close the curtains. We faced the main glazed orientation of our house to about 155deg ( South being 180deg). This was partly for views but it also brings "house noon" forward by about an hour helping the house heat faster in the morning and reduce solar gain in the afternoon at the expense of overall daily global solar gain. Seems to work well.

Here's an interesting concept about drinking rainwater untreated lifted from Farmers Weekly. It seems too logical and straightforward to possibly work.......... Water supply To reduce costs, rainwater is harvested from the roof, with two separate pipe feeds set up to supply the shed and grazing block. Water is stored inside a 100,000-litre tank, which has a valve at the bottom to monitor the water level. If it dips below a certain level, it is automatically topped up from the mains. Still, with 70% of the water supply coming from the roof, it is saving about £2,000/year on average. Mr Rowe has also saved on a UV-system by turning to the Australian industry for advice. “When using rainwater harvesting systems, there is a risk of bacteria getting in the water from things like bird droppings. But the work done in Australia suggests the bacteria live in the top and bottom one foot of the tank. “The theory is: if you suck water out of the middle, you are never exposing the cattle to risk water. “I spoke to an Australian cattle vet who was using the method to provide drinking water for his house.” © Richard Stanton Subsequently, Mr Rowe has designed and engineered a system to do just that. Hoses are suspended from two buoys that are connected to 18in-long chains to prevent the hoses from floating to the top of the tank.

I too quite like the shape and design of a simple metal building. Maybe a portal steel frame with some insulated steel panels externally might work. https://www.steelroofsheets.co.uk/categories/insulated-cladding/ Couple this with a couple of cans of high quality airtight foam, https://www.uksealants.co.uk/illbruck-fm330-air-tight-expanding-foam-gun-grade.html You'll have a very cosy garage.

Nice to see a start made, and glad to hear your marriage is intact. Concrete requires an acceptance of suffering elsewhere largely absent from the 21st century! I poured a slab with a mate for his house earlier this year. We had a concrete belt on the truck which helped enormously. Also I've found if an owner driver comes they're normally more attuned to the customers needs. I'm sure someone will bollock me but the technique I used for levelling is was to setup a cheap Lidl self levelling laser with a view over the whole site. Looking into the beam (wait for the internet eye doctors to appear) I took a level on my rake and tightly fixed a cable tie as a datum. This enabled me to rake, check and level the floor very accurately and quickly. Especially as the "pro" beep beep beep level broke on the day. Have you considered eliminating the slab entirely for the main house. Pour a ringbeam and then put a floating osb floor over insulation.

@yberllan do you work in the IMP trade yourself? Industry experience is always welcome. I watched Roger Bisby AKA Skillbuilder make a garden room last night from them and I was impressed with the kit of parts that turned into a building.

For this kind of job I wouldn't buy my own machine. I've had an 8t excavator and now a Massey backhoe. Again about 8t. They're absolutely fine for poking around, clearing scrub etc however when you take on the ground it turns out theres an awful lot of it and it's very heavy. You'd need something at least 13t and to get something serviceable probably spend £30k+. Anything cheaper will work for light jobs but once you start digging hard it'll break your heart. Seals and hoses will break daily and heavy equipment is very tough to work on. Everything seems to be inaccessible and incredibly heavy, and inevitably when it breaks it's stuck outside in boggy ground in the rain ( Ask me how I know!) Also parts are an order of magnitude more expensive than automotive/agri stuff. Get in touch with local farmers. They'll have a number for a man with an excavator who does this this every day of the week. Employing him you not only gain a digger but also his expertise. By all means buy machinery for lighter jobs, I use my digger all the time, but for serious earthworks pay for an expert man with a big reliable machine . I do.

Had a gander out of interest. A BMW 740 is 580w. Most cars probably about half that. One for an Insignia 2.0d online for £20 at the moment. Just make sure you get the plug with some wire from the scrappy too as the OEM sockets in the housing can be a pig to get into

The more I hear the more I think your architect is really clued in. Three things being talked about here, Breathability (vapour permeability), Airtightness, and Ventilation. Impermeable internal insulation materials ( phenolic, PIR, polyethene sheets) are a bad idea. They pass the test of interstitial condensation only in theory because you can draw a perfect vapour barrier internal to them. In practice this is impossible. Doubly so on a retrofit. Every nail and screw (not to mention internal abutting walls and floors) will let humidity into the wall and condense into moisture at the cold side. Mould and fungus will grow and your old walls will weaken and crumble if the moisture cannot escape. Breathable materials like mineral wool, gypsum, woodfiber, cork, hemp lime, clay + intelligent membranes are a far superior and safer option. If moisture gets in it can get out. It's the difference like between wearing goretex and wearing a plastic bag. 2 Airtightness is different. This a continuous layer somewhere into your building that allows no drafts to blow through. It is probably the most important for energy savings and comfort. It is also important to protect the structure of the building by not allowing humid internal air into the walls as much as possible. High quality retrofits like yours will tape/mastic all penetrations diligently back to an airtight but breathable layer of render like clay or lime. Make a DIY blowerdoor fan to hunt down leaks. 3. Ventilation. Firstly air for human health . It needs to have appropriate temperature, humidity, free from pollutants, pathogens and excess CO2. Secondly for the health of buildings, this really is only appropriate humidity. In practice it's only practically achieved by some electric fans running continuously somewhere. Sucking out, blowing in or both with the added comfort and energy savings of a heat exchanger. Vent holes in the wall only are as practical as a hole in the roof for drinking water, always too much or too little. Opening windows as required doesn't happen in reality. I looked at the video, it's effectively a PIV (positive input ventilation) module but ducted. It has the advantage of filtering the incoming air but will rely on good airtightness to blow stale air out through the bathrooms. Given the same constraints and the access to ducting a DCV or MEV would run ducts to the wet rooms and extract the moist air while letting fresh air in through trickle vents or wall vents. Aereco is a French company that has an elegant system of passive humidity controlled inlet vents and humidity controlled fans to only vent to the required level. It's the most efficient system without using MVHR. Another alternative is an exhaust air heat pump for DHW like this https://www.atlantic-comfort.com/Water-Heaters/Heat-pump-water-heaters/Explorer, again made in France. Whilst not MVHR, it will ensure you're not dumping hot air overboard whilst heating the hot water. @Thedreamer is pleased with his version from Joule. I'm glad to see someone is taking off gassing seriously. When burnt phenolic, PIR and polyurethane are very poisonous. Aerogel for a house can see limited use. For instance upgrading an existing heritage door in a money no object passivhaus refurb. For normal humans to buy in any meaningful quantity it's far too expensive. I found a US store selling Aerogel blankets for $325 for 0.75m2 @ 10mm. To achieve a U value of 0.2 ( 7cm) would cost about €3000/m2. Mineral wool at 22cm would cost €18/m2 for the same U value. Vacuum insulated panels are very vulnerable to puncturing, expensive and come with the same breathability issues as plastic board based insulation. Forget the space age materials is my opinion unless you have NASA's budget. Just carefully install something breathable everywhere. Maybe 10cm at 0.035w/M2k will be fine. TLDR My advice is: A good layer of cheap breathable insulation. Meticulous attention to airtightness. A continuously running mechanical ventilation system. A heat pump. Bon chance!

Mineral wool/Rockwool every time. Cheaper, better fit, fire performance. Overheating protection. The list is long. Once you have any insulation at all ventilation losses become a far more significant factor, especially in small buildings. What airtightness/draft proofing strategy have you agreed on?

No, I paid for an official test. A very thorough German came and did it.

You could put the coil inside an overheating room of the house, or even the car to extract some extra heat.

DIY blower fan. We tested 0.31ach after only a scratch coat of sand cement plaster. Most of the gaps I found were the backs of wall chases and around windows.

I too couldn't see the ridiculous price for install making sense. You can buy an ASHP for 2.5k yet the install seemed to add 12.5k to the build. Direct electric here. We insulated our way out of the conundrum.

Hi Dan, Is the front remaining open? If so insulation won't make any difference.

Is plain concrete an option, usually cheap and readily available. Do the best you can and then chuck a few hundred quid at self levelling compound if needed.

Fair enough, no to convection so. Radiation is a nicer heat. Infrared heaters can give a nice localised radiation boost to skin temp (they feel warmer) while not having to heat the air temp of the whole house. I'm not a fan of celotex. Prefer bog standard EPS , mineral wool and celluose. Just use more of it.

Not 100% sure what the arrangement is here. Are the green lines ducts ? Where is the fan located? A pen sketch would suffice.

If dhw isn't a considerable why not use mini split A2A units. Great COP and cheap.

How about, something like 100mm Rockwool between the joists. Its main purpose is to prevent the reverberating drum effect but can double up to heat insulate in your case. Structural flooring on acoustic strips on the joists. Membrane, Pipes and screed. If you want to do more acoustic improvements consider resilient bars underneath and greater mass of plasterboards (soundbloc or thicker boards or double board). An essential part of soundproofing is closing any air pathways so downlighters etc are best avoided.

Our resident @tonyshouse did this. As far as I can remembered it shortened the winter but didn't cover the coldest months. Probably better off using the insulation to make some insulated shutters I reckon.

Ah yes. I forgot about that. Typically with well constructed new builds heating is not required upstairs save a few towel rads maybe or electric UFH over tiles. We have no central heating at all....

Precast 1200mm wide X 150mm thick concrete hollowcore planks here with 75mm concrete poured over the top and some mesh. Very quick to install as craned from the truck in one afternoon. The 75mm concrete took any deflection out of the planks. Probability overkill and ended with a thick floor. A 25mm screed would probably have been fine.

We had planning, went to the bank and asked how much money they'd lend us, based on income, it was as close as made no difference €300k. We committed to spending no more than 75% of that for a builders finish. Unfortunately the house we had permission for was 225m2 and was never going to happen without running out of cash. There were some very slow legal land issues underway so we used the opportunity to reapply for planning. We changed the design to a completely rectangular box, and knocked 40m2 off the footprint. I poured many evenings into balancing overall costs and came to the conclusion a passive House was cheapest if you omit a central heating system. The end result was that we ended up with about €85k left over after the builder had left to pay for everything else. Garage, carpets, kitchen, professional fees, furniture, pillowcases, paint, you name it. Lots of stuff was secondhand and I did lots of work myself but we still spent every single cent. However we were never under pressure, for money as all the important stuff had been covered and we moved into a house that was "finished" straight from out of our rental. I can attest to the fact once you move in nothing else gets done anyway. There was plenty of stress during the build as it was but I can't imagine what it would've been like had the money situation not been so under control.

Taking a slightly different tact here. Might I suggest that your neighbour potentially isn't a bad character at all. Perhaps he was slow to have the works completed due to covid worries and felt a duty to accept a pushy contractors "take it of leave it" offer and he went ahead out of a duty to you to reinstate the fence. Almost all disagreements are due to physiological effects, ( pain, tiredness, fear, hunger) combined with narrow communication channels, (e.g forums!) when the meaning gets lost. Pop round with a cuppa coffee and a few buns, chat face to face and importantly listen to the neighbours thoughts before you go any further. This will ensure you have all sides of the story to make a reasonable plan to rectify the situation. Remember the saying " a good neighbour is better than a far friend". With a consideration you might be able to use this situation to improve life both sides of the fence.

The core principles remains and unfortunately it's not very sexy. Seal up every tiny pinhole to prevent drafts. I don't know anyone who's ever regretted building a tight house. Use lots of insulation, in my opinion the "stupider the better" cellulose and mineral wool trump PIR, and aerogel any day for a building. Cheaper and almost complete inert they'll last for centuries without degradation, shrinkage or off-gassing. MVHR is my one concession to "gadgets" but that is essentially 2 X electric fans and a heat exchanger. There after a token amount of heating and cooling (if you've been sensible with glazing) will suffice.