Piers

@BigBuilder I'm interested in this too and have also been looking at windows24.com if only as a useful tool for comparing prices of window quotes in the UK. Also talking to other suppliers in EU for quotes at the moment. Have you made any progress since your last post?

We're in the process of getting quotes for aluminium windows and doors but I'm finding the sheer number of window profiles quite overwhelming. I'm struggling to understand how to attach a value to the different elements of the window. It probably doesn't help that window suppliers seem to give conflicting advice along with their reputation for impaired honesty. The suppliers that we've gone to have quoted for Cortizo and only seem to supply one or two profiles in any case. I'm aware of other brands/profiles such as Schueco, Aluprof, Reynaers and can see that they make a range of profiles of differing quality/performance. I gather that Schueco have the bext reputation and also are the most expensive. But beyond that I have no idea how to assess what constitutes a good value unit. I'm looking for an idiot's guide on how to assess whether I'm getting bang for my buck. Also, if anyone is willing to share the little things that they regret about windows they've bought. It'd be very helpful to understand the small nuances of windows such as opening mechanisms, life-span of gas fillers, issues installing etc - basically the stuff that doesn't show up on a data sheet.

Hello! I'm looking for some ideas on how to fix a potential thermal bridge in a garage/workshop building in which one zone will be heated (when in use) and the other zones will be unheated. We're planning to build on an insulated raft in (insulated) ISOTEX ICF. The thinking behind this is that if we ever want to convert the building into habitable space, we might as well have the walls and floors installed with insulation as it'll be a lot more expensive to retrofit. Architect.pdf We've identified a couple of elements where there's likely to be a thermal bridge (see PDF) Can anyone help with a solution? If you can sketch it out that'd be an added bonus.

@WestPinch2 Did you have any luck with the Psi values?

I realise this is an old post but having just received a quote for a new supply from SSE thought I'd share. From the quote, SSE are saying that we can't take a supply off an existing pole near our property as "LV POC off this PMT exceeds volt drop limits with new load". So they're proposing to run 430-475m from a pole a lot further away. It's all a bit unclear whether they're using HV or LV. The written quote says 430m of LV and the drawings say 475m of 300mm XLPE HV. Breakdown of Charges Description of connection charges Connections: 1 Domestic Lay approximately 430m of LV cable.£169,891.38 Total connection charges £169,891.38 Description of non-contestable charges HV pole termination at WHIW E4L5 200 for new s/s tee'd from White House PMT. POC and Network Assessment, Design Approval (where relevant) £185.00 Final connection £7,831.11 Inspection & Monitoring £2.00 Total non-contestable charges £8,018.11 Total charge to applicant £177,909.49 Seeing how cheap it is, I might just get two! Back to the drawing board....

Need them for SAP calculations. @SteamyTea thanks for your response. My SAP consultant tells me that the manufacturer/supplier would usually have a list of different non-repeating thermal bridging values - the measure of heat loss through the junctions between different construction elements expressed in w/mk. I've found online a table for Durisol: I have, of course, written to Isotex in Italy and asked them to provide but am hoping someone who's previously built in Isotex (or their SAP consultant) might already have such a table to hand.

Does anyone have a table of Psi values for Isotex they can share please?

Has anyone taken the plunge and ordered Isotex blocks directly from Isotex in Italy? We're still keen on the product but a little nervous about getting the supply (for obvious reasons) Also, if importing for a self-build, I'm guessing you can claim back the VAT? How about customs duty (if any)?

We're having a debate with our architect about the merits of installing cold vs hybrid roof and would like some input please. The house will have vaulted ceilings throughout and so we're not too concerned about ceiling heights being impacted by insulation below the rafter. The architect is proposing a cold roof with 150mm Celotex XR4000 between timber rafters, 75mm Celotex GA4000 below, 25mm battens, plasterboard/timber. Steel purlins will be within rafter zone. We're proposing a hybrid with 75mm above rafters, 175mm between (full fill), VCL, battens, plasterboard/timber. Rafters 175mm @400c Architect makes the valid point that the roof will be thicker externally and look bulkier with deeper fascias. Also we'll have to insulate an external balcony to keep a level finish. She also says "The airtightness variation between warm and cold roof is negligible, it mostly comes down to construction standards on site as both can be taped at the joints etc. The detailing of the VCL for a warm roof will be trickier on site for the eaves and balcony overhang vs keeping it internal for the cold roof." I've always thought of cold roofs as "the old way" to build a roof. Warm/hybrid roofs make more sense to me. I don't want to be dogmatic about this - just trying to evaluate if there is an "optimal" way to build it.

Just as an FYI for anyone building with Isotex or Durisol who is short of a few blocks. John Pye auctions are selling off the remaining stock fom Insulhub. They have ~300 Isotex and ~200 Durisol blocks for sale. Contact Chris Eckersley at John Pye.

I've just spoken to a John Pye auctions who are selling the remaining stock from Insulhub. They have about 300 Isotex blocks in stock and 200 Durisol. If you're interested let me know and I'll PM you the email address. Or just call John Pye and ask for Chris Eckersley

@Kelvin please can you send to me. I did a trawl through @Jeremy Harrisposts but there are ~600 pages of them!

If that's a question for me: I have no idea and wouldn't even know where to start.

This is the first energy report I've ever read and I reckon that 90%+ is generic filler content like "What is a heat pump". Does anyone have a copy of a good energy report that I can look at for comparison? I've attached my EC's report if anyone wants to have a look Grey Cottage Renewable Energy Feasibility Study v1 .pdf

They go as low as 0.12. Think their standard block is 0.15 and they also have a 0.19 option. In our EC's report he's assumed walls are 0.18 (I know not why) We're getting quotes for both 0.12 and 0.15 versions

We're trying to get architects to finish building regs drawings and SE to complete structural package. The airtightness goal from the EC is 5m3/h.m2@50Pa. Should we be aiming lower? What are the things to consider to achieve this with an ICF build? Thank you this is v helpful. Can you run the FCUs from the ASHP and get it to do HW in the summer? No need for a separate unit? No, we've only just got the report from the EC who's recommending 2 systems. I think we'll want to speak to a MVHR designer to get another opinion. My EC is more academic than pragmatic.. Exactly. We'll put the insulation under the slab and then UFH on top in screed. I wish my EC had any sort of passion TBH. He's taken 4 months to write his report and I don't feel much better informed having read it. It's heavy on theory and light on practical recommendations.

Yes, the layout of the house, position of steels and vaulted ceilings makes the ducting runs quite tricky. The advice we've been given is to split the MVHR into 2 zones. It's a 5 bed house, ~420m2 with some larger volume areas (double height). The EC hasn't really gone into any detail on airtightness and that's something I need to follow up on. We're certainly aiming for an airtight house, though not entirely sure what that entails on a design level. Kind of. The foundations are stepped. The basement area will be an insulated slab with retaining walls. There's also a section of rasied GF which will be built using steel and comflor. This PDF shows the design(2)010a - Long Section Proposed.pdf

Our energy consultant (EC) has finally written his report and is recommending we install a 16kW ASHP. Peak heat loss has been calculated at 10.41kW and the EC writes He's also recommending we pair it with 7.4kW of solar PV and 2 x Zehnder Q350 MVHR systems (Two due to issues running ducting). We're planning to install fan coil units for active cooling because we're terrified of building a house that overheats in the uncreasingly hot summers. 400 litre HW tank Planning to build in Isotex ICF if that makes any difference. Heating with UFH and intermediate floors will be built using Comfloor (i.e. concrete and screed) Armed with this information I'm unsure of what the next steps are in actually selecting a heat pump and how the various elements tie in with one another (or not). Before I start engaging with potential installers/contractors I feel I need to know more so I can make informed decisions. I'm open to general guidance and a bit of technical advice (preferably couched in layman's terms!). TIA

Hi All. Hope you're all well and getting through lockdown. We're looking for an architectural technologist/techician (difference?) to take over from the architect who got us to planning. The architect was a nice guy and we like his design but his attention to detail was appalling and we feel that we'd be better served going with someone who is genuinely interested in how the house is built. We don't feel that the architect ever really cared that we wanted to build in ICF or had that much interest in the details that we specified. Just like our faithful dog he only listened when it suited him! So now we're looking to find someone to take the planning drawings and turn them into construction drawings (with a few small tweaks) as well as helping deal with discharging planning conditions. I know from other posts that some people are very against changing architects/ATs mid-project whilst others see no issue. Can any of you offer guidance on what to watch out for, what to ask for, etc - basically how to reduce the chance of regretting the change of horses! Also, can anyone recommend an AT who has experience of ICF (Durisol/Isotex) builds? I have asked Durisol and Insulhub for some introductions but I trust the experience on this forum for a (generally) objective recommendation. Thanks All and Stay Safe

I want to examine all my options. Re: foundations - I know it's possible to use ICF underground but want to understand whether we should use it. There's lots to consider with quite a few variables. One major concern is how to keep the basements dry and the choices we have in keeping water out and diverting it around the building (tanking, waterproof concrete, etc)

Undecided. Between Isotex and Durisol. To include foundations, retaining walls (sloping site), and the usual openings, lintels, etc

Hi everyone. I'm looking for recommendations for a SE for our ICF build in Hampshire. Looking for a SE who is cost-conscious and not addicted to sticking unnecessary amounts of steel and concrete into the ground.

Now this is not the end. It is not even the beginning of the end. but it is, perhaps, the end of the beginning. Coming up on 2 years since we first instructed our architect and over 8 months from submitting our planning application, we have finally been granted permission. It's been a tale of missed bat season, incompetent planning officer, excruciatingly slow conservation officer, numerous complaints and all capped off with some pretty ridiculous pre-construction conditions. But we're there! In the time it's taken us, I've done back to brick renovations on 5 projects plus a couple of loft and rear extensions plus we've had a child and a global pandemic (which I blame on our resident brown long-eared bats) Oh and we've also completed our permitted development outbuilding/yoga studio/stealth shed All I'm hoping for now is to get the foundations in before winter.

Now that's an excellent idea - I like it. Any idea how one calculates length of ground array?

@Jeremy Harris do you get cold feet in the summer?! We could put a standalone aircon/refridgeration unit into the pantry with an extractor vent. Should solve the condensation risk. I was trying to be clever by using the cooled down fluid returning into the ground array to cool the pantry Maybe it's not possible/practical