Onoff

No offense but you're sort of missing the point. Having passive (or better) levels of insulation and airtightness are what leads to very low energy bills. Do it to current building regs requirements and you're already on a loser. Every compromise is lost heat. As I always do I'll come back to Jeremy Harris's comment. Even with 300mm of EPS under his floor slab, 8% of his heat losses were through the floor. That's a continuous concrete slab with just a few service penetrations. There are then self builders on here who's houses aren't Passiv certified but have exceeded those specs.

I feel for my new neighbours. Same basic house construction as mine, circa 1930. They've just re-roofed and ewi is yet to be done. In fact their planning application waxed on about the refurb resulting in a "thermal envelope". The external finish and attention to detail looks brilliant and they've had new windows. Not sure if they're 3G but they still appear to be in the outer leaf (it could tbh be solid brick with no cavity). The place was suspended timber floors, I don't know what they've done there. The work was done by their extended family who are builders. The thing is they have an ASHP fitted before things shot up. I'm wondering how they're fairing now. Hoping for a tour sometime. I watched their application proceed and on the basis of it am seeing the same local architect tomorrow hopefully.

Does an MVHR compensate for a too airtight build?

Does this thread not prove the massive attention to detail needed in building a Passiv ezque house? OK'ish airtightness just isn't good enough. Mass house builders doing it, like is being advocated in Scotland, never going to work. Blessed is he who asks for that 200mm of tape to finish off around his window.

Thanks for spelling out the obvious. Talking of semi's...

Not really, I've just had enough of nothing happening or moving forward here. I rang the bloke, sent him the original dormer extension plans then told her afterwards and that he's coming Monday. She did say "Well we've been talking about it for a while". Of course then had to get the last word in saying "But if we don't get permission we'll be scuppered and on their radar if we then do anything". Erm...state the obvious love!

A dog rough, fag packet sketch of what I suggested above. This is one method I've considered with my kitchen. It saves taking the kitchen units down to dig up and you really don't want heat going up into food storage cupboards or the fridge freezer anyway. It does of course mean you still have an insulated room perimeter. Another concern I had was that this might shift/settle over time and there'd be a noticeable "joint" between old an new floor sections. I imagine you would put a mesh or similar down before tiling the whole lot. I wouldn't do this in the lounge I don't think as we have furniture around the perimeter and I'd want heat coming up under that. Might be a moot point for me as really the whole kitchen floor is too high and wants lowering to match the rest of the house. This and the step up will become an issue for us in later life if we become semi immobile when older or wheelchair users. Hopefully we'll have frozen to death / been eaten by rats before then...

Rang a local architect with a view to engaging his services. He's coming to see me next week. I picked him based on 3 recent, local applications by neighbours all involving different architects. Out of the three, he seems to have the best grasp on local planning sensitivities.

Quality with quantity that...except for the tiling...

Amazing, my nephew sent me that exact photo on WhatsApp the other week as an example of good plumbing. He has a sore bum too apparently. Didn't know he'd been to Bristol recently.

The basin size is usually 1 1/4", bath is "1 1/2".

Yeah, I know! (Note the position of the comma btw, that's me being pedantic). 😂

The 1 1/2" usually relates to the inside diameter of the pipe. Can't you bathe in the stream? 😂

Have a look at @Nickfromwales detailed comment here on p13 of my mega thread:

In your house maybe! I'm staying in the lounge where it's 11.6degC any warmer and I might have take the blanket and wooly hat off! SWMBO currently outside trying to thaw the kitchen waste pipes that run around the house perimeter above ground. Frozen solid meaning the washing machine, dishwasher and kitchen sink can't be used. Boiling copious kettles etc. When I said about sorting proper drains...you'll take too long, the mess etc. Usual insanity.

A brilliant concept but what will ensure the mass homebuilders do them properly with the attention to detail that's needed? Going to need to be a sea change too in the attitudes of many trades.

It's corduroy too, very 70s! Someone was chucking it out. Still, it keeps our feet off the lounge floor, currently the thermometer there is showing a balmy 10.9degC...the one mid air in the centre of the room is 17.6degC. Heating has been on since 9am with room stat set at 30degC. 4degC in the bathroom though it did get up to 5...

Here you go @zoothorn, my lounge. Suspended timber floor, clay air bricks open to the elements. I've hung a thermometer from the light fitting with the probe midway between floor and ceiling. Just in front of the second "P" in HAPPY. Temperature is reading 20.5degC. Then there's another on the pouffe with the probe on the floor. That is reading 13.4degC. So one probe directly below the other. No wonder our feet are freezing!

Sarah Millican's boyfriend would love your shed!

I suggested this. Even that my jobless 23 year old could do the digging etc whilst I'm at work. SWMBO thinks we should wait until Spring. ???

Tbh the bathroom did feel nice and warm, even without heating until I punched multiple holes in the ceiling for the body dryer, speakers and down lights. Might be my Christmas mission to make good those areas.

It was alright until the tiling! Tbh, now I've done the one room I'm completely confident to do the rest of the house. Just wish SWMBO would get onboard.

As others have said, multiple times it'd be an idea to do a test dig. Yes btw I've done similar in a single room. First clear the room! -Kango the floor: -Remove the floor to separate pile outside. Think I shifted about 70 or 80 rubble bags then the soil on top: -Dig down. The depth will vary according to your floor build up/design: -Distribute the soil where you can outside. It grows btw. -Grade the removed floor / break up to reuse as a sub base. I used max 40mm. -Level this off. The paint splodges are where I had stakes banged into the dirt to ensure a constant hardcore thickness: -Compact: -Blind with sharp sand: -Lay a layer of 25mm EPS: -Lay a DPM. Note there's a 2" thick upstand of EPS around the perimeter. This is to help take up the expansion of the slab when it heats up. (I did too add extra expansion strip). -Lay PIR min 150mm. Did mine in 2 layers, 50+100, staggered the joints and foil taped: -Lay UFH pipes, cheap even if you don't use them. I used Polypipe panels but you can staple to the PIR if you put another plastic membrane over the foil face: -Lay A142 mesh: -Lay concrete 100mm deep. I had various areas shuttered off for the part sunken bath and wet room corner. I used "wet" mixed concrete. I forgot to add strengthening fibres to the mix for this! The mesh should negate the need.....I hope. The concrete comes to the height of the expansion/perimeter strip. -Tile: Ask multiple stupid questions along the way and take years off forum member's lives in the process! 😂

Have a line of bricks level with the top of the lintel and a uPVC packer underneath?

Have you got a wall plate to go atop the blocks? Add a 55mm bit of timber or 50mm uPVC extension piece?