Nick Laslett

One thing I don’t miss about the house build is looking at building regs. They are just so badly written and hard to navigate. The fire regs for structural elements table seems to have grown massively since 2019. https://assets.publishing.service.gov.uk/media/67d2bb074702aacd2251cb94/Approved_Document_B_volume_1_Dwellings_2019_edition_incorporating_2020_2022_and_2025_amendments_collated_with_2026_and_2029_amendments.pdf So as others have already said, 2 storey dwelling needs 30 minutes protection for structural elements. British Gypsum white book has a plethora of solutions https://www.british-gypsum.com/specification/white-book-specification-selector/steel-protection Here is one with 12.5mm FireLine board

I came across this website when researching stairs. https://www.knostairs.com/kno-how/draw-stairs/ They seem to have lots stuff to support this process. https://www.knostairs.com/kno-how/draw-stairs/staircase-and-handrail-drawing-courses/ They use RhinoCAD, which has a 90 day free trial.

@Walshie, 3.6kW is loads of energy. Don’t feel bad. Outside the oven, kettle and tumble dryer that is everything else covered for 8 months of the year, assuming you have gas central heating. Just get a solar diverter for your hot water tank. Then 6 months of the year the solar is heating your domestic hot water. The tank is your battery. Obviously an EV car is also a good place to put excess solar energy and is also a massive battery. In 5 years time vehicle to grid will be a more viable system setup. My long term plan has been to use my EV battery when that approach becomes available.

Great suggestion. I did a few areas of my slab where we had EPS in place to be removed later. We used this approach to drop the threshold level for the patio doors. @WannabeBob, you should try to avoid having any finished parts of the house in place until as late as possible.

Hi @HughF, thank you for putting this together. I have been looking into decentralised MVHR options for a single room with en-suite. So to add to the list for other people looking at this topic, Zehnder do two dMVHRs, ComfoAir 70 and ComfoSpot 50. https://www.zehnder.co.uk/en/indoor-ventilation/solutions/mechanical-ventilation-with-heat-recovery/zehnder-comfoair-70 https://youtu.be/2Kk-njZlHGk?si=dUphDlw8HPI5TFnE These would be at the top end of the price range, and possibly overkill for a lot of projects.

@WannabeBob, I use these insulation fixing from Fischer on my build a lot, because I have ICF walls. https://www.fischer.co.uk/en-gb/products/fixation-on-etics-insulation/fixing-in-insulation-material Rawlplug also have a version. They screw into the EPS/XPS the FID II plus 80 can take 0.20kN of force, which equals 20kg weight. https://rawlplug.co.uk/product/r-iso-plug-insulation-fixings/ I prefer the shorter fixing from Fischer and the long one from Rawl. I was skeptical about how secure they were, but did a test with the 80mm fixing in the EPS300 and was surprised with how much force they could take. This was just the fixing, no adhesive. When I finish my build, I plan to make a few YouTube videos testing some of the EPS ICF fixing solutions I tried.

@WannabeBob, great post. I hope you get some good replies. There are so many instances like this, where no matter how much you prep, in the real world there needs to be some workaround compromise. I don’t know if CT1/OB1 would be strong enough to hold the door? My go to solution for many parts of my build. My passive foundation upstand is only 90mm thick, so the door could still be fixed to the concrete, but they had to compromise with how the Sill would be fitted, because the door was set back. The only issue, is if the warranty or workmanship isn’t being owned by someone.

My understanding is that radon barrier is a typical requirement in Ireland, and because Tanner and Kore are both Irish based, it is a standard detail that they include.

I don’t know, made no sense to me. Here is my construction detail from Tanner, the DPS under the ICF is a little different. The MBC crew did my foundation, you can see from my photos what they did. This is Jeremy Harris construction detail, he had an MBC foundation and timber frame. You can see that the DPC is consistent with my photos. I’m not trying to confuse or mislead with my posts about DPC placement. Building controls seem to be very touchy about this requirement. Please seek professional advice, don’t take my posts as advice. @ChrisJ, sorry if I have made things more confusing.

I agree, I don’t think it is critical. Here is the generic Kore construction detail, see the small green line for DPC under ICF block.

Same spot on foundation pour day. You can see the DPM is still overhanging in this photo. According to my drawings you would put a second DPM strip under the ICF blocks before you start the wall. Not sure how necessary that is with ICF walls. Here is a close up. Before the concrete.

Also on my build the vertical rebar connects the ground floor walls to the slab, then the first floor walls to the ground floor walls.

According to this research paper, thermally modified Ash is more acidic and corrosive than regular Ash. Thermowood Ash had a pH value of 3.75. https://www.semanticscholar.org/reader/50b811003eb14f0d700560e08f45fe22cb8370c1

We used Ash thermowood cladding from QTD with Lindab coated Steel guttering. Been up 2 years, no issues yet. https://www.qtdgroup.com/thermowood-ash-cladding https://upbuildingproducts.co.uk/products/steel-guttering/ Thermowood is more expensive, but it has a lot of long term benefits. *Edit: Advice from American Galvanisers Association Acidic woods or resinous/sappy woods such as cedar, pine, fur, and larch are aggressive to hot-dip galvanized steel and known to stain the HDG surface. Instead, dry, non-resinous wood species like poplar, ash, and spruce are recommended woods in contact with galvanized surfaces. Additional reference information regarding the corrosive effects of additional wood types are provided in Table 1. https://galvanizeit.org/knowledgebase/article/corrosive-chemicals-and-galvanizing

@Temp, please could you give more details on the resistance tester for the windows. I had a disagreement with my window fitter which way round the panes should go. I clarified with the suppliers, but am still a bit paranoid, any more details would be appreciated.