Leaderboard

We’ve just done our final concrete pour, in fact two pours in one week. From ground floor to gables in two weeks with Easter in the middle is quick, a little too quick to enjoy. We can now get a real sense of how the house will look. Next week we are ready to start work on the roof. Before building the first floor, a temporary floor was laid around the room perimeters using 12mm OSB. This was done to provide a working area to build the blocks from and allow bracing to be put in place without damaging the final floor. 12mm board seemed awfully thin to walk on! . With our builders now familiar with the wall plans the blocks went up very quickly indeed. In practice it takes longer to do the bracing and shuttering than to do the building. Not having to cut blocks on site is a major advantage, not just from an accuracy point of view but it also makes the site much cleaner. Some ICF sites look as though it’s been snowing with polystyrene. As mentioned in out last blog entry we had the option to do a single pour combining the first floor and gables. We’re really glad it was done in two stages, attempting it in one pour would almost certainly caused major bracing issues and risked the block work due to the higher pressures resulting from the depth of concrete. Never thought I would be happy to shell out £1000 on a pump. Having no experience of other build methods it’s not easy to evaluate the pro’s and con’s of each system. For us, the need to use concrete pumps has to be the worst aspect of ICF. It just seems like you’re never quite ready and there’s another dozen details to attend to before it starts. With multiple companies involved for boom pumps and concrete delivery, it’s both expensive and difficult to get people to turn up when you asked for them. Our last pour was scheduled for 11am and the concrete lory finally arrived a 3:30pm...To add to the entertainment the pump has to be vented after use. This involves a set of guys you probably won’t see again and want to be elsewhere dumping large volumes of concrete on your site. After three pours we have somewhere in the region of three tons of set concrete to break up and pay to dispose of. Some of the last lot got dumped on next doors newly block paved drive. Lots and lots of cleaning up. It’s not too much of a surprise that the builders don’t include this in there list of responsibilities. Definitely the Achilles heel of the ICF build method. Enough moaning, it’s been a long couple of weeks with many disturbed nights worrying irrationally about being a lego brick short at the end of the build. We now have a house, no roof, but hey we have to do something next week.

old pair of tights stretched over the F7 as a prefilter?

Personally I would lie down on the ufh. ?

Given the cost of running pipework and controls for the towel rails, compared to the cost of just sticking a low power element in a towel rail, I'd say it's probably not worth the hassle. Our towel rails are both fitted with 70 W heating elements, and are on a time switched circuit, so they come on for a total of two hours per day. With both on they cost less than 5p a day to run. We usually only have one of them on, so the cost is less than half that.

Another option is warmed air through the MVHR - only possible if your energy requirements are very low, else you have to heat the air a lot and this is unpleasant for the occupants. I use UFH at ground and basement, and heated air through MVHR in bedrooms.

It starts!! Not much to look at, this steel stuff... Rusted to within an inch of its life! Despite this, all about as sharp as you could possibly imagine - nearly sliced my finger off picking the first one up! Still, some judicious use of gauze and tape and ready to carry on. My part-time builder came round to help me chop the steel, weld it all up, etc. After a day, we aren't as far through as I expected... That's one cranked beam, made from 180x75 PFC, and installed adjacent the wall. It's standing on a leg near-side which runs down to an I-beam in the floor, and some 120mm Thunderbolts bolted through a welded plate into the reinforced concrete wall at the far end. The timber is covering the second cranked beam, which has since been fixed in place in the same ways. Those 2 cranked beams will form the bottom flight of stairs, once the 50x50x3 box section is welded and/or tek-bolted to the PFCs for each tread. Here's the side view: On top of the landing part, we will be putting another pair of cranked beams (the same as these two but upside down) set at 90° (going up to the right) that will be welded onto a steel plate we have affixed to a double posi joist at the top of the stairwell. So far so good, but between the weather and the uneven ICF internal walls, it took 7 hours to get to this point... Let's hope tomorrow is more productive!

I bought my stairs from Stairbox with solid oak tread, engineered oak strings and veneered oak risers. cost was £1160 compared to £2260 for everything in solid oak from a different manufacturer. I can't tell the difference between the solid/engineered and veneered oak.

Another +1 to Wilo.My cheap manifolds from ebay came with IBO pumps that were dire. Both now changed for Wilo which are incredably quiet. Grundfos are also good, but it might be worth asking if there is a Wilo option?

We have both, a Grundfos on the UFH manifold and a Wilo on the DHW preheat heat exchanger. Both are reasonably quiet, but the Wilo is a fair bit quieter than the Grundfos.

I have a double winder staircase from TK stairs Basic MDF & pine. I am going to clad it in birch ply with 25mm birch ply treads.

I use high quality dust mask when working near fine sawdust or anything dusty, I have a big box of pre filters and have two of these inserted before the main filter, when the front one is dirty I chuck it and put the one behind to the front and a new one at the back. The main filters last for years this way. When I one day get my mvhr built I will use the same principle of at least one good cheap pre filter before the main filter and maybe a set of tights to !

I think just having screed rather than chipboard will probably be where the main improvement comes. There's a lot more mass, which should reduce the noise somewhat. Is there already caberdeck there? If not, I'd be trying to decouple that from the joists with something resilient. Another important thing for sound reduction is airtightness. I'm convinced we get a lot of sound transmission through the service cavities on external walls, but I admit not being sure of exactly what path it would be taking between floors.

We built our house with ICF. I was very fortunate that there were two contractors well practised in using ICF so was confident in moving away from timber frame (both open and closed panel) which I had previously built with. I certainly don't regret switching to ICF, and wouldn't hesitate to build with it again in preference to timber frame. Our vaulted ceiling is insulated with a combination of earthwool between and Kingspan across the rafters. Had I known that a local contractor was obtaining the relevant equipment, I think I would have been very tempted to use on site spray foam insulation. Unfortunately for us, we were too far along when it became available locally and any benefit would have been far outweighed by the cost and hassle of unpicking work that had already been done. Anecdotal I know, but our neighbours house is built used a closed panel TF system. Similar sized houses, insulation levels the same (or actually higher for the TF), similar amounts of orientated glazing for solar gain but out heating costs our lower, and we seem to have a more stable internal temperature (appreciate there are many more variables which could effect this). We've always built using a main contractor, and I wouldn't change that route as for us, it has represented the best balance between cost / time/ quality. In terms of the house itself, I will in due course be posting a full blog entry on the topic of what went well, changes we would make etc. In summary, and in the absence of a whack more cash, there is very little we would change - some minor tweaks to the layout of the bedroom section, perhaps not improvements, better described as alternatives. One thing I do regret is keeping glazing to the north side of the house to a minimum - the decision being based on both heat loss concerns and more importantly, that we anticipated the view wasn't going to that good. As it turns out our landscaping really opened up the view such that I think we probably should have had double rather than single windows to bedrooms two and three, and indeed probably put windows in our bedroom on the north side (albeit this would have increased glazing costs overall). Lots of positives I could point to, but the stand out for me is the preplumb ASHP heating / DHW system we went for (Mitsubushi Ecodan) - auto adapts to what is required and works flawlessly with zero input from me. I am however less impressed with our MVHR unit (Vent Axia) and would probably go for something else if doing it again.

I wonder if it got clogged by all that Saharan sand that came up with the warm weather at easter. Either way, all that stuff is better off in the filter than your lungs, Lizzie.

I have a TF PH and I use electric towel rails in the bathrooms, supplemented with warm air heating from an EASHP through the ventilation system, to heat the house. If my house was at the higher end of PH heating requirement I would rather use skirting radiators than UFH.

Indeed you can run UFH at lower temperatures than radiators but I'm not entirely convinced that it makes that much difference in a well-insulated house if you run the radiators for long periods of time. E.g., in the leaky Edwardian house I'm renting at the moment the average temperature of the flow to the radiator in the study over December 2018 and January and February 2019 was 30.46 °C to kept the room around 22 °C most of the time it was occupied. (Maximum was 54.75 °C). Here's a particularly cold period from January 17th to 24th when I left the heating on overnight for the first few days (Thur, Fri, Sat, Sun). There are only a few short periods, when the house is heating from cold, where the radiator runs continuously; the rest of the time the heating is cycling on and off. For the days when the heating was on continuously (Fri 18th to Sun 20th inclusive) the average radiator temperature was only 29.17 °C. Radiator output is not quite linear with temperature so the output if it's just held at the average value will be a bit lower than if it's cycling up and down but I don't think this makes a huge difference, certainly not a much at the T⁴ effect that some people obsess on.

A couple of other factors (for me) in my decisions for UFH: with an ASHP I can put the HP into reverse and add cooling into the house. Cool-floor. I doubt you can do this with radiators, if the water is below about 15C you risk condensation. Have used this in the very hot summer (2018) and it does help, though not as good as direct air-cooling would be. Passive heat distribution - by running water through the UFH I thought I could re-distribute heat e.g. sun shining through the windows heat the floor and the energy is shifted to the north side of the house or to my basement. Not sure if this actually works in practice. In theory @jonM 's architect is right. With a PH your heat requirement is between 1 and 3kW for a small to medium size house, so the complexity and expense of UFH is not needed. In theory you can get away with a single fan heater. But you are comparing point to distributed heat sources and this is where comfort (human perception) comes into play. I once came across some research about how humans perceive warmth and hence comfort. Unfortunately I did not clip it and have been unable to find it again. The research was in the context of flooring materials. It concluded that, when people walk on a floor that feels cold (e.g. hard tile) they feel cold even if the air temperature is fine. But if the floor feels warm (e.g. carpet) then they feel warm even if the room is a bit cooler. I believe UFH goes some way to providing the "all-round" warmth / comfort perception. One thing to note in UFH vs rads is that rads are great when you come in after a walking the dog in the cold and need to warm your body up - you can lean against the warm surface and this is a lovely feeling. You don't get this with UFH.

My corners were fabricated to fit, we also had end pieces made to finish off ends of runs.

UFH every tine. Very little difference in running costs When you have a lot of glass and low windows Combined with open-plan Its difficult to find somewhere to site all the radiators Also should you sell on at a later date It’s a massive selling point

The "no upstairs heating" thing does seem a bit variable. Like others I have no specific heating in the bedrooms. I have UFH in the bathrooms mainly so the tiles are comfortable to walk on. Most of the time the bedrooms are warm enough, but in a really cold spell they occasionally get a bit cool, so then I light the stove and heat the downstairs to "indulgance" level (about 25 degrees) and let the heat from that work it's way upstairs. I do have electric points for panel heaters but I don't expect to ever be using them.

My experience is different. On our PH-standard build, and despite no insulation between ground floor and first floor we do not get sufficient heat from below to keep bedrooms warm enough. I was getting conflicting feedback from other people in this situation so decided to fit direct electrical heater in upstairs MVHR ducts as a precaution. Plus low-energy towel rails in bathrooms. I'm glad I did this as we do need it. In winter I keep towel rails on 24x7 (perhaps about 50W on average - guesstimate). I also have a thermostat and timer for upstairs MVHR heating, it is usually enough to switch on for 1 to 2 hrs each morning and early evening to take the chill off in the rooms, without over-heating for sleep.

Worth taking into account what temperature you like your bedrooms at, whether you have any living areas upstairs, whether you have cathedral ceilings etc.

I wouldn't bother with first floor heating at all, as I doubt you'll need it; enough heat will rise from below. We don't have any heating on the first floor, bar low power heated towel rails in the bathrooms, that only come on for an hour or so morning and evening. The bedrooms are plenty warm enough, although I did fit fused connection units in both so we could add small electric panel heaters if needed (they won't ever be needed, as it happens). The only thing I'd do differently would be to fit low power electric mats under the tiles in the bathrooms, to just take the chill off when standing on them in bare feet. The bathroom floors aren't cold (typically ~21°C) but a few degrees warmer would feel nicer when in bare feet. If doing this, then the only thing to watch would be to keep the power right down, as our bathrooms get quite warm as it is, so any floor heating would have to be limited to only times that the bathrooms are in use.

I was given a very strong recommendation by an experienced Passivhaus M&E designer and architect to use radiators on the basis it is cost effective, quicker to respond than burying pipes in a slab and easier to maintain. You can still circulate water at lower temperatures for efficiency purposes but will need to oversize your radiators. The thought of underfloor heating is tempting and more aesthetically pleasing but I don't think it is an open and shut decision particularly in a passivhaus. You can also put the radiators anywhere in the room in a passivhaus. They don't need to go under a window as in a conventional house.

Probably UFH, but bear in mind that UFH will always be less efficient than radiators, although for a house with a low heating requirement these losses won't cost a lot. As an example, we have 300mm of EPS under our passive slab, and the UFH heat loss to the ground beneath is ~8% at the maximum heating level.

From a comfort perspective, UFH every time as it removes localised hot-spots and cold-spots. Are you using a ASHP? These are more efficient at low temperatures, and rads will need warmer water.

I don’t even think radiators are worth a second thought. Just from the point of view that they take up wall space, I wouldn’t ever consider them.

Although I like woodwork and have many woodworking tools we wanted a “cottage” in brick (although most houses round here are rendered and the planners like “sameness” so had a fight on our hands) I liked the quick erection of TF and having visited @JSHarris was mightily impressed with his build. I also like heavy houses (phew, nearly said thermal m##ss?). We are very lucky that a local builder with a very good reputation gave me a fixed price on brick and block to my specification (passive principle) with me doing all the timber work, roofs, floors, windows etc. ( my second cancer put paid to me doing the roof tho ). What I like about brick is its lack of maintenance and “cottagey” look. I have nothing against timber frame and I suppose I could have had one with a brick skin but the sums did not add . I am extremely pleased with our build and we have very little in the way of cracks, just windows cills shrinking a little. I did pay a decorator to paint and he commented that our build had fewer cracks than any other new build he has been on ? Just had some bad news, the bricklayer who did such a good job and has become a good friend has just had a stroke, he is 6 years younger than me, fit as a fiddle, ex military, does not drink (much). So today’s motto is live life to the full, life is not a rehearsal, we are only here once so enjoy it.

Just to be absolutely clear, this forum HAS NO CONNECTION WHATSOEVER WITH ANY COMMERCIAL ENTITY. BuildHub is not connected with any supplier, builder, manufacturing company or whatever, and is run completely independently, by an association of volunteer members. Anyone can help run this forum, and the minutes of meetings, etc are available for inspection on request.

Nationwide free detailed advertising on TV, over 11,000 hits on the website and just ONE confirmed sale. That sums it up, that the plots are over priced. I don't know what the answer to making plots available for self build is, but this is certainly not it. Unfortunately. What price do large developers pay for a plot? Certainly not £250K each. If schemes like this cannot deliver affordable plots then perhaps it is time that planning law changed and demands that say for every 100 houses granted permission to the mass developers, one must be sold at the same plot price for self build? Sadly this seems to be turning into a prime example of "never underestimate how badly something can be run if left to local government"

Cheapest 3 bed detached in Bicester according to Right Move is currently £295,000 About the price of a BARE PLOT at Graven Hill now. That makes £100K about right for a plot, and if you are careful, your self build house may cost no more than just going and buying one. A £300K plot needs to be a large plot in a stunning location with stunning views and no neighbours (and no fear of new neighbours) not a small plot on what is going to end up a very big housing estate. I am sorry but I think the project has "gone wrong"

We used slates: The ground level is being raised about halfway up them later on.

We left a 100mm gap between bottom of the render system and what was then expected to be ground level. I dressed this with an additional strip of 20mm thick x 200mm deep EPS over the EPS cladding the basement wall, digging out a bit to get the depth. We then ran our paving flush with the top of the render (to allow no step entry to house on all sides) but set 100mm back to from a 100x200mm channel round the house. Next job is to line the EPS with Ubiflex flashing and backfill the channel with decorative white stone chips to act as a french drain, leaving a 100mm gap between the render and air gap and the top of the stone. When rendering the garage with the same system, I managed to get the Ubiflex onto the base of the garage wall first so it runs under the bottom batten - thought of it too late for the house. However if the render is getting fixed then I may hold off and apply it then. Will send a pic later.

For me hindsight is a wonderful thing unfortunately. I could never have envisaged that my hubby wouldn’t be around to finish the build and then when he got sick he said he would go through everything with me ‘when the time came’. But admitting when that time was didn’t happen as to him I think it was a sign of defeat, and then later he was on so many drugs he couldn’t even log onto his bank account let alone document the build. It’s not too terrible TBH now that the heating is fixed. It’s just really the ST, the electrics in the garage, the MHVR and numerous bits of wiring that I’m not sure about.