Iceverge

Windtightness in a sealed roof. Stop wind driven rain blowing in. It might mean less membrane flapping noise in the wind.

Yes. It's remarkable really. It's almost like an absence of cold rather than heat though. Maybe towel rads would be nice in the bathrooms for point heat. We have spurs just in case. However I seem to be be somewhat obsessed by this and find myself making spreadsheets with 30 year coat benefits analysis of the merits of a €100 towel rad. It probably means it's not too much of an issue. I have a lot of time for bill butcher. His denby dale videos are excellent. Plant is an open question. MVHR, UVC plus plumbing. Electrical box. No real reason they need to be colocated however. A thing that bypassed me was there is no need for a hot water cylinder upstairs. Originally I was planning a thermosyphon boiler cooker and in later designs the cylinder just got left there. It would have been better in our utility. Keep the MVHR easily accessible. Filter changes are important. The areas I highlighted above could be quite tricky to install thermal bridge free. Timber frame in cavity wall construction. The sticky out bit with a steel to support the upper wall will be almost impossible. Timber frame, EWI or ICF are your friend here.

Issues. 1 Vibration from the units and 2.Noise through the ducts. Solutions 1. Floor mount the unit, mount the unit on an external wall or hang the unit from wires or use rubber feet. 2. Avoid very high flow rates through too small ducts. Use acoustic silencers. Metal ones aren't too dear. Or make your own.

welcome welcome. You'll need (site cost) + ( £1000/m2) + (£100k) Difficult to design without a site. Difficult to pick a suitable build method without a design. 1. Get the cash. 2. Get the site. 3. Plan your house. 4. Built it. In the meantime I would encourage you to research passivhaus. Applying the methodology and PHPP is the cheapest and best way to a comfortable building.

We don't have a system, just one of these. In Ireland so it's not E7 per say, but a similar concept. No PV. Shiny gadgets are fine but remember they will break down in a few decades max. Often before they've recouped their capital cost in a low energy house. Good design and good fabric will last for centuries. Do PHPP. A collegue told me recently of a completely glazed WSW gable on their house, new build, Bregs. It regularly reaches 35-40 deg if they don't open windows. They're looking at a fairly strong 4 figure sum to install blinds internally which will only partly mitigate the problem. Southern windows are not the issue, Overhangs/brise soleil easily sort midsummer overheating. East and West are much more problematic and really require external movable blinds. Do you have plans to share? Do you have planning permission?

https://passivehouseplus.co.uk/magazine/new-build/heart-of-oak

Yes, an UVC keeps all the DHW At 47-70 approx. Any water expansion is taken care of by an expansion vessel and over pressure cases by temp and pressure release valves. It requires a qualified person to install and inspect it annually. (although many don't bother). There is a worst case situation where all safety devices fail and it explodes. You can draw almost all of the stored water inside off as useful hot water as the cold water in the bottom won't really mix with the hot water being drawn off. A thermal store is a large tank full of water that will never see the light of day. It is heated by your heat source directly in most cases. A DHW coil passes through the tank which absorbs energy into the DHW so it emerges hot, cooling the large body of water in the process. No safety or over temo devices required. Worst case is with a huge boiler you could end up boiling the store and it would vent as steam. Not terribly realistic. No issues with DIY install or maintenace. Disadvantage is that you need to store either a lot more water or water at a very high temperature as once the temp of the store drops near to 40 deg it can't supply hot water any more. A thermal store at 45 deg will have almost no DHW capacity. An UVC will have lots. With a Thermal store you can run UFH heating directly from the main water body in the tank. The short answer is put in UFH and a large (300l minimum)UVC and an ASHP so long as it's not huge money (<£6k). Its the soundest advice I can come up with.

Probably worth the opinion of a structural engineer, no point in coming back to square one in a year or two.

It's an entirely different concept of heating to a conventional house. Fluctuation doesn't happen really. It will eventually drop to about 14 Deg if unoccupied. Even after a day of a powercut during the big storm recently the internal temp was still at 20c. With hindsight I would have liked to have put UFH pipes in the floor slab. Maybe buried in 150mm-200mm of concrete. The more the better I reckon in this case. You could defo store enough energy from E7 to heat the house all day. You would be able to run the slab at a very low temperature too which should make any complex control systems unnecessary as well as maximising the COP of an ASHP. Yes. No. You need to keep on top of it though. If you miss an evening heating the bathrooms might end up at 19deg which feels cold. 20-21 is fine. We use almost exactly 10kWh per day with 2*adults 2*small children DHW. All heated E7 in a direct UVC. From memory about 1kWh of this is losses from the direct 300L UVC. It works out at 260L per day of water at 40c. The heat pump payback on DHW is much longer than space heating as the SCOP drops from about 4-5 to maybe 2.5-3. One thing I would say is to fit as large a cylinder as you can. 300l works fine but with guests we need to heat outside E7 hours. A larger cylinder can store the same energy at a cooler temperature too so will have lower losses. Plumbing isn't rocket science. I replumbed our place after the plumber made a hash of it. Hep2O is an excellent system and very user friendly. ( If I was to do it again) 1. UFH in a thick slab. One zone. 2. As large a water cylinder as possible. Maybe a giant 600-1000l coil in tank thermal store. This would avoid G3 requirement and the need for a seperate Willis heater for UFH. It would allow easy ASHP connectivity with no buffers etc. ( Beware ASHP and smaller thermal stores are not a good mix to the high water temp required kills the COP) 3. DIY plumb it. It's very doable.

19% of world's grain exports. Don't forget the embargoes on Russia produce too. Before this the price of nitrogen fertilizer was already 3 times higher than last year. It supports about half of the world's food production.

Used radiator fan inserted in OSB cut to size of a window sash . About £30 of material. Cable and croc clips to your car battery. Much more puff that the official blower door.

What m2 is your house? That basic calc is only really vaild for MVHR, airtight and thermal bridge free. If you start running up to high leakage and areas of poor insulation all bets are off. A windy day will effect a non airtight (+windtight) house tremendously. What does your barn use in practice? Be careful of overestimating window performance. An small opening passivhaus certified window with a centre pane U value of 0.5W/m2K can quite easily end up with an overall installed U value of 1.5. Lessons learnt from the forum and personal experience. It's best to size your heating system to allow for. 1. Off peak E7 heating (the house structure/slab can buffer the heat for non E7 hours) 2. To allow DHW as well as space heating on cold days. 3. To avoid heat pumps running at max capacity and low efficiency, icing problems etc. 4. Not too large that your boiler is constantly cycling on and off. Don't over complicate your heating system in a passive house. If you can feed in some energy somewhere central it'll be enough to keep everything ticking over nicely. We just use a £30 plug in heater at the moment from about 17:00 til 08:00. The house is between 20-21deg. It seems to make little difference where the heater is placed so long as the doors are open.

You can buy an Atlantic (french) Explorer 270L ESHP cylinder for about €2200 Inc VAT in Ireland with a 5 year warranty. No reason that one wouldn't suffice. Haven't seen them for sale in the UK but I'm sure theres similar avail. It has an inbuilt solar PV divert function , would require just standard plumbing to the cylinder and 2 X 160mm air ducts . No outdoor unit or extra electrics as max current is just the same as an immersion. It dawns on me as an easier DIY install. As it is a dedicated DHW solution I'd be tempted to believe the advertised COP of 2.5 - 3.0. https://www.toc.ie/products/explorer-fs-heat-pump-cylinder-270l-imp112.html

You'll need to bump the cavity to 150mm between the leafs. You prob have this anyway I haven't seen any examples of moisture getting across the cavity with beads that were installed correctly. Normally it's because of a badly fitted cavity tray, mortar bridging the cavity or an unsuitable mineral wool pumped into a very narrow cavity. There's a few threads here about boards in the cavity. Have a read through.

I'm thinking an all in one ESHP like @Thedreamer has might be an ideal fit. You can buy Chinese ones for about €1500, European ones more like €2000.

Have you priced an immersion in a coiled cylinder to get you started. For DHW your COP might only be about 2.5. On E7 it might be decades payback depending on your usage.

How about an ESHP with a coil. Heating DHW and ventilation in one . You could use the heating coil as a take off to run the UFH. Granted the extract air would be stealing heat from the cabin in winter to heat the cabin, perhaps running it in external air only/partially then would work. Maybe it's a terrible idea?

Welcome welcome, Can you give a better description of your house construction please. Type of walls, floor roof windows etc. Is it a big bang renovation or piece by piece? Beware the advertising for "green" materials (although I am a fan). Your primary route to air quality is through airtightness and mechanical ventilation. If you couple this to eliminating thermal bridging and enough insulation you'll have a very healthy house. As ever, care will need to be taken to ensure you're not trapping moisture in the structure with a renovation, or a new build for that matter. Some natural breathable materials can be safer in this regard but they are not a panacea.

I would advocate a seperate airtight layer with a good membrne and proper airtightnes tape. It will only amount to hundreds of pounds but will have the most dramatic effect on the comfort if you get it right. You will save a few £ on the tape with less joints too if you use a membrane. IIRC you're on a tightish budget so you may be able to use seconds PIR with imperfect facing then too to save a few quid. By the way are you planning to insulate the service void? It would seem a waste not to, espically as mineral wool is about the best bank for your buck when insulating.

Welcome welcome. Block build here. It was the cheapest but airtightness and detailing very tricky re thermal bridging. These are vital. A developer near us just competed a dozen houses using Kore insulated raft and I think amvic ICF. These guys aren't picking a build method for fun. Airtightness + bridging should be top knotch. Bricks over ICF should work fine althought I'm not 100% sure how you'd tie the facing bricks to the structure.

Sorry to hear that @ProDavebut hardly surprising. I wonder is this a standard response. I had a colleague who having smashed an alloy on an unmended pothole wrote to the council. They sent a standard "not our fault" letter twice but paid up instantly on getting a legal letter. A new alloy was probably cheaper than paying a solicitor for them. I wouldn't be surprised if this company made a similar calc. Back to the practicalities. Do you think the issue lies with the render system being inherently unsuitable for the application over woodfiber or in general use in the Scottish climate?

An new airtight house would be better as the air would not get overly dry in windy weather. At the moment with the leaky structure you have high and uncontrolled throughput of air, this combined with the heating being on will result in a very low RH. Overly dry houses are just as bad for health as damp ones.

sorry for the confusion. the ewi query was directed @bighouseproblems

EWI an option?

Hi @Selfbuildnewbie and welcoms. I actually quite like the layout apart from the store. Like @TerryE says its an expensive shed. Turn it into a home office imo. The outside looks a little wonky as @CharlieKLP says. I would start by posting a couple of pictures of the style of house you were going for. We can take it from there. The orientation of the house and the form factor are good. If you could tidy up some of the junctions you could convince it to be a passivhaus. Have you considered it?