Leaderboard

At design stage for the trusses. Regardless of whether or not you choose to make it a room, I would be speccing attic trusses so you can make use of the space for storage. I for my double garage it was approx £400 extra.

We completed our build 18 months ago, so this post is more of an academic exercise in light of our experience with the system, for the possible enlightenment of others. Or ridicule perhaps. We have a Zehnder Q350 with extraction connected radially to 3 shower rooms, a WC, a kitchen, a utility room and a plant room. The supply feeds go to three bedrooms, the large living room (2) and the' office' (2). So 7 ins and 7 outs. A couple of matters arise from our usage. We have auto humidity boost turned on, so for showers etc the fan ramps up with no human actions. This is great, except if someone gets up 'early' and has a shower. The still recumbent others are then subjected to the quite loud boost noise that ensues. Not a terminal sufferance but a factor to consider. Perhaps we should just turn off the auto feature when guests are here. It is a bit fiddly delving into the menus on the unit in the plant room, but not impossible. Or just leave it off and manually boost when necessary using the app on the idevices. Or never boost and let the removal of the moisture take a lot longer. The other matter is a bit more delicate and concerns ensuite facilities and their use. Activity in them is not always in quiet mode and sometimes can involve less than pleasant noises. MVHR principles dictate that doors have large gaps at the bottom to enable air flows from the supply bedrooms to the extract en suites. This also enables easy sound transmission to the adjoining bedroom and its occupant. Can the collective knowledge and brains comment on the principle of reverting to air and 'sound proof' doors and instead providing a supply feed inside the en suite, albeit at the opposite diagonal to the extract to maximise air flows. Not a major 3rd world problem but worthy of discussion perhaps.

If on your founds you build a few courses of thermal type blocks this could form your break and reduce the thermal bridge. Will also help you get it perfectly level. You will obviously need to check the blocks are rated to a high enough N to withstand the weight that will be above.

Worth giving Hilliard Tanner a call, too. He's been designing passive slabs for a decade or so now, and probably knows more about them than a lot of SEs. He wrote this report for Kore, which is probably worth a read: Kore Insulated Foundations Report.pdf

If you fit that I will come up there and rip it out with my bare hands. Stop worrying and do it properly

What you are proposing to build there is more akin to the party floor between flats in a conversion project, and it's likely to meet ADE requirements for that (DnT,w + Ctr >=43 dB / LnT,w <= 64 dB). For internal floors of a house it will be pretty much as best as you can do without independent ceilings, and way over Rw 40 dB. A couple of key construction considerations - don't screw the resilient floor boards down to joists. - make sure the floor flanking strips are installed and only cut off once the skirting is installed. - make sure your dry liners use two lengths of screws for the resilient bars, as too long on the upper board can go through and screw in and bridge to the joist. In terms of mineral wool 50mm / 24kg/m3 would likely be fine. If you find that floor or two layers of board is too much in terms of thickness, you could use resilient joist caps (for impact isolation) and one layer of 18mm floor board, thought may have a slight derogation in airborne acoustic performance.

I fail to see what that Neptune tray gives you avoiding any work that the Wedi involves...either way you've got to cut some concrete out. Your dpm looks to me like its under the first 2 layers of eps so its 300 deep...you won't break the dpm. Why is chopping some eps 'not on'....surely cutting the concrete is the PITA. Where is your shower waste cast through your slab, and what size pipe ....is it in the exact spot you now want the tray waste to be?

what would the future use be, garage or accomodation? if accomodation it could be done later if eveything is there and you are only applying for a garage

make provision for both but wait until completed and signed off

Here you go - https://www.changeplan.co.uk/u_value_calculator.php

With 150mm of 0.035 mineral wool instead of PIR in timber frame U=0.147. It is software but not currently available.

Where you are expecting your kitchen cabinets, put horizontal battens across at top of cabinet height so you have something to fix to, otherwise it is unlikely the cabinet fixings will line up with the studs.

That uses the Secoh pump I switched our older BioPure unit to. It's also a bit quieter than the original Secoh pump that was supplied with it: https://webuildit-ltd.co.uk/product/secoh-jdk-s-eco-air-pump-60/ If anyone has one of the older BioPure units, they can swap the pump over for one of the newer Secoh JDK-S Eco pumps and gain a worthwhile reduction in electricity usage. The swap is easy, as they are the same size and have the same pipe fittings.

Looking at the picture, your plot is above the road / pavement so anything falling from the build may land on passers by. If I have that correct ......... I can understand your worry about an ICF blowout with the danger to people below. However, i can’t help but think one accidental mid-handling of a Lego block, that falls, would be far more dangerous. I think your risk assessment for the build must include protecting passers-by. With ICF the danger is only during the pour. With the Lego blocks it is as you lay every single block unless I am looking at the picture incorrectly.

heres another way maybe if your man made long thin versions of these then you don,t even need a crane and just hand fill the holes? another way --wonder if blocks this size are available in uk

There is no need for cavity walls. With attic trusses the room will be within the inside space of the garage anyway and easily insulated.

Say you had a double garage with single skin block walls with pillars...like I have Could you ADD an inner skin, straight off the floor slab, maybe even in timber, in order to give support if adding an "upstairs"?

I've been downloading random planning applications from the planning portal to see what I can learn from them. One of them included a nailing schedule. I suspect it was more to mandate the contractor, rather than for regulatory purposes. Bottom left of this sheet: AGREEMENT_OF_RECOMM-3238667.pdf

nothing in NHBC, https://nhbc-standards.co.uk/6-superstructure-excluding-roofs/6-2-external-timber-framed-walls/6-2-4-load-bearing-walls/ 95mm galv nail gun nails would be fine

Yes, it was attached to my post in the Topic started by @ProDave above that I referenced on Tuesday. To help you, I have attached again. 38167 HRV Volumetric Design 2015-4.pdf

Recently got this from house of canopies as there isn't much room above the door for a substantial structure. We just wanted something to keep the elements out when entering/leaving the house. Seems ok

Probably for a few reasons. The building industry in general is pretty conservative, and would rather stick to doing things the way they've always been done - probably one reason why we stick with labour intensive stuff like laying thousands of brisk and blocks to build houses. Another reason may well be the cost of transporting and erecting large blocks like this, that are too big and heavy to be lifted by hand.

How would you deal with the big thermal bridge at the base of the blocks. though? You could probably design a passive slab, with a reinforced ring beam around the edge, that would take the loading from the blocks. That would then give you insulation under the floor slab, under the blocks and up around the edge ready to be continued with EWI up the walls, so no thermal bridging at all. If you fitted UFH inside the concrete slab then you would effectively be warming/cooling the slab and the walls, like a giant storage heater/cooler.

we are all waiting to see the final range of blocks and if they can work from a plan and supply a jigsaw .drawing for assembly 200mm blocks would be best if possible. still not sure pricing will work out --but hopeful just the thing for Australia with a concrete roof as well

TBH that house in Holland looks very good, if you can achieve that then I’m happy to eat some humble pie, as I was probably the first to say it was a silly idea. Keep the pics coming.

Clearing a site by hand is bloody hard work, get a man and machine in and get your levels right from the start. Working from a cleared site is soooo much easier. If you want to control weeds etc around the outside old carpet is great (and free).

Looks passive slab too ..?? Are they custom lintels I wonder or cast in situ with rebar ..? I would check with them how the floors go in - this looks like a 200mm block arrangement (do they do a flat top block..?) and the joints seem to be sealed up with spray foam. And as @Jeremy Harris says, the decrement delay will be impressive ..!!

That will make it much much more of a viable option.

@Crofter wake up....

I asked same question of blauberg agent in uk when talking about a centralized mvhr system for new build his suggestion was to accept small loss when in use and have it separate direct extraction to outside with a flap type exit . better than blocking up the mvhr filters and coating ducts internally over time with gunk just what I have been told you make your own mind up I know what I will do when i get that far

I'm re-creating a few threads from e-build where I shared experience of building my 'passive' basement, useful starting points for follow on discussions --------- The original poster was enquiring about waterproofing basements and dealing with the conflicting advice from architect and contractors. My reply: Unless you're 'in the water', which your ground investigation will reveal, warrantied waterproof concrete on its own should be sufficient.We're on undulating layers of clay, lynch hill gravel and seaford chalk so relatively free draining and don't hit water until 6m. Basement excavation was 3.5m so we went for 300mm waterproofed concrete with a land drain around the slab base to a 5m deep soakaway and a 1m wide clean stone backfill.We used an approved Sika contractor and had regular inspections from Sika during the pour, checking water bar placement, penetrations etc. We now have their 15 year insurance backed warranty against water ingress.The overall 10 year build warranty (from Ark) was satisfied by this as were BC.We have friends nearby who built close by the Thames and their basement is half submerged in ground water - they used Glatthar and were very satisfied but it wasn't cheap.We did our entire 122m2 basement for £120k with a single contractor which included demo & cart-away of existing building, excavation & muckaway and the construction of the basement itself - plus all services (fouls, rainwater, water, gas & BT duct & electric). I sourced the under slab & wall insulation separately as they weren't familiar with it at the time.Glatthar wanted about £100k for just the basement construction and we would have had to fund the groundworks separately - which would have been at least half as much again.We also designed our basement as an 'open box' with no structural internal walls so we are free to change the layout if we wish, currently having it framed out which is only costing a few £100 in labour and timber.Good luck, lots FUD surrounding basements and many of the contractors push their preferred systems (typically with additional cost) in a take it or leave it fashion but get what works best for your site and gives you the necessary peace of mind and suits your pocket.

I’ll come and help you ...