Leaderboard

If you know the calculated U values of all the walls roof, floor and windows you can calculate the heat loss pretty well. I used Jeremy's heat loss spreadsheed and the result was very accurate. I confirmed the building performance almost as soon as it was complete, long before the UFH was down and the internal fit done, just by running a single low power electric convector heater for a few days and plotting internal vs external temperature and calculating the heat loss from that and it agreed with the heat loss spread sheet. So I then knew I could trust those figures to design the UFH system.

Another one at 48 degrees here. Found by trial and error to be the hottest I can just about hold my hands under if I draw if sink of washing up water just from the hot top. I don't see any point in having it hotter. Treated mains water into an unvented cylinder has no opportunity to get bugs in so a weekly cycle to heat it hotter is pointless. You only need that if it's not mains water or it's a vented tank.

I got tons of use out of my DeWalt laser and the matching laser receiver. You can’t see the laser outside on a good day but the receiver can, and beeps low or high frequency depending if you’re above or below the laser line, there’s a visual indication as well. I did my drains with it, sat the laser on a solid surface, attached the receiver to a bit of batten that I’d marked showing the depth the drain needed to be for every meter away from the house in relation to the (random) level of the laser. There may be smarter ways of doing it but it worked a treat.

Thank you very much everyone, that's really helpful. It is great to know that my early thinking processes are not too far off, and I'll have a rummage around the site to find other people's calcs and design thinking. I'll also upload a couple of my early sketches, as I can see that people on here have been really helpful with other people's designs. Part of me thinks that I'm being unimaginative with my designs, as it is a fairly square box, but I wanted something simple to construct and not too many fiddle details to sort, so it is nice to hear that the box shape is also going to pay dividends on the heating front. I'm agree with @SteamyTea about the jumpers, happy to dress properly for the weather, but my old house was properly cold & damp, and it started to have an impact on my joints. From everything that I am reading on here that is highly unlikely to be an issue with a newbuild timber frame with the right U values and orientated properly. This is the little Everhot, and I was thinking of putting it in the living room, as a bit of a focal point. I don't have a TV, so it might be nice to have something pretty to look at, and woodburners don't seem to go with the ultra-insulated ethos. You can turn it down to trickle heat, but I suspect that it might overheat the room given what people are saying. However, it is electric, so no need for flues, vents or anything like that, and you can stick your feet in it on a cold day 😁

Well I have just finished my build in North Devon, not passive but not far off, a 5kW ASHP with UFH , heating required only a couple of months a year, plenty of hot water all year. (And I very rarely wear a jumper indoors). Orientation is key IMO I have a south facing conservatory and that heats the house in the shoulder months. Having MVHR means no trickle vents (draughts) and heat recovery. I was told my house would overheat with South facing and a conservatory but as yet I have not needed cooling (which the ASHP can do with a bit of work).

Design out thermal bridges, design in insulation, ducts MVHR, solar, shading

Welcome to the forum.I am hoping to get some PV too at some stage and am learning also. In the depth of winter generation will be small. In the middle of summer the sun is higher so orientation is less critical. It's the shoulder months that having a good orientation and lack of shading helps out hugely. Most panels are 350-450w and take up an area 1m*2m. So your house roof looks limited on the SE facing pitch to maybe 6 panels?? Hard to tell. This would be 2-2.5 kW so a useful contribution. Theres a website PVGIS.eu https://re.jrc.ec.europa.eu/pvg_tools/en/ You can play with this to see you annual generation. I reckon it would be about 2000 kWh and peak at roughly 9kWh per day. Our DHW demand is 10kWh/day so assuming you have similar usage and choose to install a diverter to an immersion you could use all your spare PV on heating water. A battery would be unnecessary. If you look at midsummer solar and creat an account you can draw your roof and it'll auto generate a package.

There were two obstacles blocking me from proceeding with my build. After finding a professional who could sign off the compliance paperwork (I couldn't afford the Architect) I had a boundary issue which I agreed with a neighbour to resolve and then I had to add a window to the plans and submit them for approval before I could lodge a commencement notice and get going. Issue 1: When the house was built years ago a hedge was planted at 90 degrees to the house fronts but the land registry boundary was different, meaning when I go to put in a new driveway, some of this land is owned by the neighbour. This could be a major headache when selling the old house to fund the self build. The neighbour was very agreeable and it only took a few goes with the solicitor to get all the forms signed, get some mapping errors resolved and the land registry map THEN matched the Architects plans / assumptions they were drawn up with at the time. Simple fix but it took a call to the Land Registry office to get hold of the person who was dealing with the query. As they were on holidays for a week, the system automatically demotes unresolved issues from "waiting for attention" to "request for more information". They dealt with the issue the same day they were back and thankfully the revised map coordinates all matched and the file / folio was updated. Case Closed!! Issue 2: There were a number of planning conditions attached to the grant of planning permission. Some were protect trees, etc but one was to add a window on the gable end for passive surveillance of a public road. I've written about this before but the grant of planning was very clear that updated drawings would be required to be accepted as compliant before I could commence building or else!! I wrote to them in September 2018 looking to have this removed and told them why. Never got a reply to this date. I had other issues finding a path through the building regulations without access to an Architect. It was September 2021 when I got my finger out and had another go! I expected it would be a few weeks, it was an easy decision for someone to make, I'd get the ok in early November and I could start selling up / planning my build from January 2022. Christmas came and went, no word. I did reach a very lovely administrator who did reply to my enquiries but had no idea when a decision would be reached. There was a change in the law in December 2021 (Ireland - Republic Of) requiring responses to compliance issues to be made within 8 weeks. I assumed I would be fast tracked to clear the backlog but as January went and February was reaching the end I wondered if everyone like me was at the bottom of the pile as the newer applications would be given priority. I made that exact enquiry and it was politely suggested that if I resubmitted the same drawings they would THEN be covered under that new legislation. This was going to mean a winter build though, not what I wanted at all. But I needed that decision. So on February 28th 2022 I resubmitted the plans and waited 8 weeks. In the ninth week I had received no word from anyone but thankfully as it was a bank holiday they were running a day or two behind and on the first day of a two away holiday break, my first in three years, I got the word, the compliance submission was approved. Now, I had a fallback plan in mind where I could extend my planning by another 5 years - this was a hangover from the last crash, making it easy for people to extend planning due to that disruption - unknown to me however it was rescinded last year. I only found out recently. My planning expires next June 2023! I can only extend it if the building work is expected to be substantially completed by that time. Bit open to interpretation but I really need now to make a call to proceed or not. If I can get started by January 2023 I should be well ok. Later and it might get fun!! I'm on variable rate % on my current house so I need to get all my ducks lined up and sell to proceed. Anyway, long story short (amazing if you're still reading this!) but I can now lodge a commencement notice. That clears the way for my to realign the driveway, put in a new boundary fence to split the property and sell the house, and build on the side garden site I've been hoping to do for the last 7 years! My mortgage application has expired and a lot of the quotes have too. Can I still afford to build and find reputable trades to do the work? Remains to be seen but the plan is to finish all DIY on the current house, get it cleaned up ready for sale and go from there. 7 months of legal/planning issues finally over. I've read and heard of far worse but a window in my case has been partly to blame for a delay of 3 and a half years!! Certainly the last 7 months for sure but that's how it goes. But with a few really good people onside (land registry, planning office and solicitor) a result was reached and delivered. And I just started a laying a new Patio last week in frustration....!!

I did question the real benefit of having pir on upper floors and was advised to keep it to make hearing more responsive. 25mm PIR is not that expensive so just carried on even though I feel it has little benefit as the aim is for the whole house to be same temp anyway inc floor structure but at least is something to clip ufh to!

And congrats on popping your 1k cherry

Plenty are, but just because you are paranoid it does not mean they are not out to get you. We have had a smart meter at millstone manor for a year, doesn't work / won't commission, bulb sent a chap from Siemens, he looked at it, said it wasn't commissioned and drove off. We have to send photos of the screen to submit a reading and because we are on a dual tariff and the meter is only reading one tariff we spend inordinate amount of time arguing about how to split the bill. The smart meter on the build works a treat though - looking forward to seeing it going backwards when we get the PV🙄.

OSB to about 15mm off the screed. Same for PB. Tanking should be done after plastering, not before. The tray gets fitted ( bonded ) back to the surrounding walls with a decent amount of clear CT1, and then no water can ever get to either the PB or the OSB. Cementitious tile adhesive gets used too fill the 15mm gap whilst tiling the floor, which is pretty impervious to moisture. The aim is to keep the water where it’s supposed to be, so the quality / integrity of the tiling / wall covering is key to success.

I am in the North of Scotland and I reckon the shallowest cover on my mdpe is probably about 400. We've had some fairly cold days of about minus 10 or so with no bother. I'd be more concerned about cover depth for mechanical damage.

I prefer to call my many lacks of skills opportunities to learn...whether I actually manage to take advantage of those opportunities is another matter, which I refuse to discuss 😁 Yes, procrastination is a big one. 1. I find myself procrastinating because I'm worried I've made the wrong decision so leave it some time to make sure it's the right decision. God, what a hole that is to get into. 2. Another one is 'organic design' or in other words, designing things as you go and changing your mind, a habit that feeds the procrastination of No 1. (Mind you, this way you do eventually get exactly what you want.. so far me and my whole family have been very happy with the decisions that took this route. It's some of the quick and poorly considered ones I regret.) Another thing for me is that stupidly optimistic tendency to think it's going to be easier that it is. I can now never forget the time honoured advice of Lao Tzu from over 2000 years ago that said something along the lines of: always plan for a journey to be much harder than you think. I wish that'd been at the forefront of my mind when I started, but we live and learn. Now I'm aware that writing this post is a form of procrastination because I'm trying to fit a cutting list as efficiently as possible onto some sheets of plywood and I can't decide whether to use the very expensive Birch plywood or some cheaper softwood plywood to build numerous kitchen drawers to go in carcasses that I'd originally planned to be cabinets....🙄

I set mine to 48’. Very adequate.

If it's an invented system, there's no need to heat to kill.

It's your responsibility to provide the earth. If you look up the standard detail for the temporary supply connection kiosk, it'll be there. I'm amazed the meter was installed as you're meant to have everything earthed and tested before that stage.

Well I did no calcs whatsoever and many here will chide me for admitting it. I built with a fair bit of insulation, double glazing and attention to detail regarding air tightness, bought a 5Kw ASHP as a punt and it all works fine. I do have a woodstove as backup (and the looks on a cold winters day) and plug In heaters for bedrooms if the temp is dire (not needed yet). I don’t see why you have to size a heating system for the two coldest weeks of the year . Despite @ProDave using Jeremy’s heat calcs and it working ok, is was not fir Jeremy, he ended up needing more cooling than heating after it was finished, but we think that is down to the location (sun trap in deep valley) which don’t tend to figure in the calculations used.

I have this cheap laser level for tiling... https://www.amazon.co.uk/gp/product/B092HXDGS3/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1 The main feature missing from the cheap ones like mine is the ability to move the horizontal line up and down. This means if you want to level a curtain rail the laser level has to be mounted at the same height on a tripod or similar. Some come with a bracket for fixing to a wall or similar but it would be a lot easier if the level could be placed on the floor or a table and the beam adjusted to move the horizontal line up and down. Otherwise he green one is plenty bright enough for indoor use. Not tried it outdoors

It seems heating is a bit of a black art. That's really hard to accept when you've decided to plan and get things right and part with all your hard earned cash... It seems to me you can only be about 80% sure how a building will perform in real life. Keep reading until you reach a point you can accept you have protected the downsides for your situation as much as possible.

I've used my Lidl Parkside €30 laser plenty. I found it more accurate than our builders DeWalt equivalent. However you're restricted to working inside or at dusk/dawn outside. That is unless you're willing to look into the laser beam itself.......

I looked at the Octopus heat pumps but had the feeling they were intended for retrofit, i.e. high temperature HPs. If you are going for UFH throughout, you only need a low temperature heat pump. These can heat your hot water OK but can't deliver the temperatures needed for radiators. Take a look at the Cool Energy ASHPs -> https://bit.ly/3sfBf6L. We have just had our electric supply connected and have Octopus electric only tariff. Once you are connected and on their tariff you can switch to Octopus GO which gives you 4 hours of 7.5p/kW at night which can run the ASHP, or can be dumped into your hot water tank. Simon PS There's plenty of info on the forum about all of the other questions you've asked as well as some blogs from members that have been through the design process explaining how they made their decisions.

Not just the total amount, it is how the power is delivered. If evenings are just a light or two and a TV. Hardly worth getting £3k of storage for a 100W load.

Welcome welcome. Reading this and looking at your requirements my mind instantly turned to cooling not heating. If you require 16deg in the attic you'll need air conditioning! . Your design sound eminently sensible. Minimal outside wall makes a house better to heat and cheaper to build. Given your location passivhaus will be easily achievable with a good builder or a package build like MBC timberframe. Q1. Easily in a new house with good insulation. Plan on 300mm EPS in the floor. 300mm EPS/cellulose/mineral wool in the walls 3-400mm cellulose in the roof. Q2. Yes avoid gas. It is bad for internal air pollution and health. We cook on induction. Cooking is better than gas having lived with both. Cleaning the hob is simple. The only annoying bit is the touch controls are a pain at times. ASHP can generate plenty hot water. Size you tank as large as possible though 300l minimum. Bigger is better. This will allow you to store your water at 50deg meaning better ASHP efficiency. Q3. I don't know much about them but they're AGA style electric cookers AFAIK. The smallest one in the range does 1.5kW which on its own is lightly to exceed your house heating load for most of the year. Assuming it will take an age to heat up like cast iron cookers of yore you'll lightly not be able to get inside the kitchen with the heat by the time it's ready for use. I could be wrong and it might be ok in a large open plan room, but caution is required. Q4. If you share some sketches there's plenty of knowledge here, most of us have learned through getting it wrong! Q5. Pass. Other thoughts. Build a compact, airtight shape with due regard for overheating. ( Appropriate glazing, shading , blinds, ventilation, high decrement delay roof and wall buildups) Use an ASHP for UFH on the ground floor. Get one that can cool the slab too. Put a multi split A2A unit ( air-conditioning) upstairs on the 2nd and 3rd floor for cooling and maybe winter heating (you really won't need it) Best of look and looking forward to following your progress.

Kim There are no easy answers to your question. But there is basic school physics. ASHPs and jumpers would be normal in any house. Why would you want, in a UK winter, to be dressed in Cornish National Dress (even in Devon). If people want a very hot house, then fit a larger heating system. The way you design, and orientate your house can have a large effect in the energy usage, it is all about surface area to volume ratio. PV on a roof will absorb about 20% of the energy hitting it, helps to keep the rise in temperature down. Cooling can be combined with MVHR. MVHR is usually designed for minimum requirements, but there is nothing to stop you oversizing so that a usable amount of heating and cooling can be delivered/dispersed. An ASHP can cheaply and reliably deliver DHW to 50⁰C. Plenty hot enough for a bath. Just a case of sizing the storage cylinder correctly. Really just a case of sitting down and working with the numbers. Dull and boring, but pays dividends.

Why would it not be allowed - it is and welcome to the forum. PV is all about area, angle and shading. If you can max out a South ish facing slope at about 35 degrees with no shading for the vast majority of the days then you can generate well. You then have the challenge of using it. A battery helps and with associated controls you can then run appliances and if the battery is full perhaps some can go into the immersion heater or, worst case, be exported to the grid. There is loads on here about how much you can expect to generate and that's may be your starting point.

Thanks Joe, yeah I was concerned about one of the doorways getting very congested where the pipes would go to the open plan kitchen living dinning area I won’t need to go through loadbearing walls as there aren’t any internally. yeah that was my plan also.

Hungary I’m eating a bacon and egg toastie, on brown, with brown sauce. That’s what hungry is doing

Good man Nod your making great progress, my sub floor block work going in on Monday, hope to be pouring sub floor next week

If it's just a bare plot with no construction started, I believe 'non-residential' SDLT rates apply.

Indeed - one of the mitigations I mentioned earlier but, unfortunately for willbish, not available in COB form. Interestingly there's a relatively new integrated pixel IC in the WS28XX series - the WS2815. The first iteration being the WS2811 which is an SO8 IC that can tolerate 12V and sink current for up to three seriesed 5050 RGB LEDs. Then came along the WS2812 which was the first to integrate the RGB LED and driver within the same 5050 package. These have the highest pixel density but can only operate with a 5V power rail. This is a nightmare as the current is three times higher than the 12V tape and things really do go south at the end of a 5m run. But now there's the WS2815 which can tolerate up to 12V per LED. This extra headroom allows for long tape lengths without colour shift/brightness uniformity problems but at the expense of actual brightness. In order to dissipate the higher volt-drops in the IC's the LED current is significantly restricted. Not much of a step forward really but it demonstrates there is a problem in the world of LED tape.

Your PIR will not conform to that, you deffo need to get either some SLC or some sharp sand and ‘blind’ those shallows.

So basically, based on the expected lifespan of the equipment, this is a goose which will continue to lay golden eggs for between 10 and 20 years. “Less typing, more fitting people!!!”

The plans are agreed and going to pre-planning before submission to council . There should be some hurdles in this conservation area , but architect seems positive.

So we have a provisional move in date which is in early May. Let's see if it happens... already today I've spotted a glaringly obvious and stupid mistake. The tiler, who was clearly instructed by the architect in my presence (and in the presence of the foreman) as to how to tile a small area of tiles, spelling out the setting point for him, has somehow ignored those instructions and tiled, grouted (including with the necessary tile trim) incorrectly. So now I have to toss up whether to insist it is redone, which will waste half a day or so, or live with it. It's just so prominently wrong. So annoying.

Sorry if you’re having some trouble? I’ve designed houses everywhere. Honestly the thing that makes a poor design most of the time is the clients. If you can find a good designer, you can work within any planning restriction to get the right design.

Welcome. Especially so to someone from my clan's own county. As @SteamyTea hints, 'eco' is a tricky adjective. But do not be put off from your determination by the dismissive comments about planners above. Being seen to make an effort in ecological terms is no bad thing: even if there's a range of opinion about what that actually means. It forms part of the mood in which planners make decisions. Our architect knew that our planners were very keen on ecologically sensitive design. And while the arguments presented above are technically correct, the micropolitics of an application matters. While discussing our application in a In a public forum, one local councillor openly said that; "The reason this application will be accepted is because of its eco-credentials" I ignored the comment at the time. There's no way of weighing the accuracy of the remark. Except that it was made. As to digging a test pit..... Get the test pit specification. Hire a digger. Enjoy making your own. Great fun. Good luck Ian

Good idea. Put the whole thing in its place. Someone with your experience understands sleep deprivation. You will lose sleep. But we're all here - not much we haven't faced. Keep the questions focused, and evidenced: that helps us help you.

Thanks . Our budget needs to be trimmed as we can’t spend more than the house can be worth and markets are tetchy . I’m going to talk to 3 estate agents who could advise on realised value on completion. im off for the sun now ..

Thanks . I will ask for a schedule of works in detail . I’ve just got to talking budget . Definitely need to open more talks as we have only talked planning so far . been reading a 8 page saga of self build and the issues faced and need to get out in the sun or I won’t sleep with all that could go wrong . Back tomorrow.

Well we had 47 piles, concrete caps then steel posts, steel ring beams and then timber frame up from that. House sits at 300mm of the ground one side to 2.5m the other, thats over a distance of about 6m max so its on a pretty steep slope with trees all round.

On a more serious note... Built a small, soda can water heater of my own design out of scrap. Achieved 50degC above ambient. Sort of a poor man's solar thermal. Then, given my attention span issues I got bored... Keep meaning to make a bfo 8'x4' one.

I have to agree that having neighbours, relatives and passers-by pissing in your ear while you are spending a shedload on a complex building project is enough to push most people to their limit. Put them on ignore. Hopefully this is the dark hour before the dawn.

Loving this thread! I'm just waiting for the passive house police to come along (and to be frank I've seen a few posts from current and past forum members along these lines). So don't forget some of the important rules: 1. Kill the cat, cat flaps will not be tolerated. 2. Remove or reduce all windows. I know you've bought a plot with a view but seriously saving on your energy bills is way more important than a view. 3. Make sure you go paperless for ALL bills etc. There is no way you are having a postbox. 4. Bury your partner under the patio. Far too risky that they may open a window. 5. Kill the dog. Can't think of a reason why other than enjoying yourself cannot be tolerated. OK, I'm having a bit of fun BUT you are going to drive yourself to the edge of insanity doing this self build lark, nothing is more stressful. SO BUILD YOURSELF A HOME NOT A HAUSE!

This post appeared on ebuild, and since it is the work of many people, I reproduce it here. It's a shadow of its former self because I can no longer make the links to the comments to which the bullet points refer. Some you win , others you lose. So, because the text without the link is useless, I have deleted some references to the authors. I have not deleted the names of the original authors who registered with us in the hope that they can provide us with a link to relevant material The checklist is not definitive. Over time I will link this checklist to comments on (buildhub and elsewhere) which substantiate the point made. Your comment on this list is particularly valuable because any work done here improves the validity of the list. And so is likely to save you time and, hopefully, money. Heating Checklist Background reading and considerations Fundamentals Get a feel for what you already use Consider applying PHPP to the design to derive a heating requirement Use J S Harris spreadsheet{J, got a link to that for us?, Ian} Play with PeterW's FingerInTheAir MVHR Checker (PeterW#5) { Peter, got a link to that for us?} Heat Calculations Passiv? Do you need heating at all? Look for Thermal Bridges in your design How are you going to manage cooling? Consider Phase Change Material Storage. Stitching ASHP and UFH together On mains gas? No brainer - it's cheapest Cost benefit analysis. KISS Separate out DHW. Use instant water heaters Selling your house on? Higher temperatures needed? We are all getting older Higher lower occupancy rates in the future? Which thermostats to fit? Smart? Analogue? Radiator? It's not easy. But KISS - off the shelf. (jsharris Blog whole entry and discussion ) Underfloor Heating (UFH) DIY or not? End of lay (Nickfromwales#7) Plot the loops out on graph paper (TerryE#12) Best layout (NickfromWales#15) Useful summary (Alphonsox#17, and Nickfromwales commentary on that #27) ) How to deal with the pipes to the manifold before second fix Testing for leaks (declan52 #25) Avoid piping under toilet and sink traps (nickfromwales#29) MVHR By definition, MVHR = air tightness Forget a traditional fireplace, therefore. MVHR wishlist Where to put the vents? (jsharris#10 et seq) Keep pipe runs to a minimum (PeterStark #10) Minimise 90degree bends (PeterStark #1) Insulate all SUPPLY ducting (PeterStark #10) External Vents at least 2m apart (PeterStark #10) External vents slope downward (PeterStark #10) Fitting metal joists? Fit rigid ducting first (PeterStark #10) Supply to living and bedrooms (PeterStark #10) Extract from wet(ish) rooms (PeterStark #10) Mind yer bonfires ( jsharris#3) Location of MVHR unit Noise concerns: fit attenuation boxes (jsharris#11, jsharris#2) Type of ducting Radial design explained (jsharris#6, whole thread worth a read) While you are at it, try this (jsharris#6) Think through the cooling issue (jsharrisblog 38, 03:48, 1andR whole thread, jsharriswhole thread, TerryE, whole thread, hazymat, whole thread ) Bio Mass / Wood burners A cautionary tale (Steamy#1) The British Medical Journal on the subject (Steamy #1) Heat Pumps (ASHP GSHP) What's your heat load going to be? (Steamy#2, DeeJunFan#3) Are they worth it? (jsharris #4) Caution (jsharris as above) ASHP and DWH (jsharris #7) No need for DHW feeds to all rooms (jsharris#13) jsharris blog post(s) (jsharris) but see recent entries (part 41 and elsewhere) in relation to DWH Controls, how? (jsharris blog 38) Run slab from room stat? (jsharrisblog 38, 03:48) How to cool the house? (jsharrisblog 38, 03:48) Solar: Thermal or PV? FIT considerations RHI considerations Which Solar or PV? (Declan52 #1) PV for Hot water (recommended by jsharris, Ed Davies Blog, accessed Jan 2016) *But* consider separating out DHW. Use instant water heaters (jsharris#5) It's (PV) a no-brainer (Nickfromwales#6, jsharris#8)

Times that by 22 and you’ll realise what a real problem you have……..

Its going to be a long night lol. More Cornish liver oil is required.

I’m always up for a challenge.

I blame this forum . Spend all my time posting crap and commenting on crap . If it wasn’t for this forum would of finished my build years ago . Tempted to sue for compensation but haven’t got time as I need to reply to this post .

I guess this highlights the huge difference in construction build costs and pm2 costs between different regions. Your cost to just buy a block is just over my cost to buy and lay a block.