SBMS

I know. Am waiting with bated breath for someone who knows what they're talking about to laugh

It's got that! Swim turbine included. and a harness to attach you (or something..)

It's nice the first response was enthusiastic! I thought I might get a load of "don't do it it's a massive waste of money".. Am still not sure it's worth it! I've got young kids so just thought they'd love it (then they'll grow up, move out, and I'll fill it in 🤣)

Haha thanks - if it's a goer I'll put up some progress pictures and commentary (then everyone can laugh when the water table gets in and floats my pool out of its hole)

I was thinking of concrete retaining wall, lined with maybe 150mm PIR, and then a concrete base - not sure if PIR in the base would make much difference to heat loss? Any engineers out there?

To be fair that included all the groundworks but still crazy

Yeah I looked at these, but I think this is just for the shell? Then there's all the filters, pump equipment, cover, installation, heat pump, swim turbine etc

8m x 4m was £117k... without a cover and 1 light. This is an 8x3 with an electric roller cover, heat pump, a proper swim turbine and 20 odd jets (hot tub style) as well for £41k...

Thanks @Pocster. I got a quote for a pool and fell off my chair. Then found this which is a fraction of the price... Its just the groundworks I'm clueless about. The builder can't believe it's as straightforward as they suggest (he keeps asking what's keeping the water out - whatever that means) and he's asking if it's not more like a 'mini basement' (which is £££)..

We're currently considering a (probably crazy) idea of sinking an 8m long x 3m wide x 1.5m swim spa as part of our self build. We've been looking at ones that are entirely self contained, and just 'pop' into a hole in the ground, with a bit of access either end to change pumps etc. The supplier has sent some construction details which basically outline: - a 215mm block retaining wall - a 100mm reinforced concrete slab - a soakaway and sump pump I asked whether any form of waterproofing would be required, and was told generally no. Likewise no shuttering etc. Am I missing something, or being incredibly naive to think we just dig a hole, build a wall and pour a reinforced slab? This is indoors. I've attached the details sent by the supplier.

Might be worth asking your timber frame manufacturer if they have psi values. why timber frame out of interest? Have you considered masonry or had any quotes yet?

Your build will almost certainly fail minimum sap requirements using the default values. That’s pretty much why they removed ability to use standard details. We went to our cavity insulation provider and their in house team calculated all the requisite psi values for most of the E values. Warmcel Then provided psi values for many of the R values. most sap providers will want custom values and won’t chance ‘making them up’ as they may face audit. what’s your construction makeup? Ours was a 200mm cavity so there were t any readily available.

They do actually fill small to medium holes as well during the blower. Their initial blower tech will indicate where they are so they can help with filling them up. The mist then does the smaller holes and effectively replaces the need for a parge coat on inner blockwork by sealing it. They also provide consultation at the outset of how to do your wallplate junctions, chamber floor junctions etc 👍

Think it was near 5.7m. Wouldn’t do that again.

Also - don’t do B and B floor. Hated it on last build. Flush thresholds are difficult (can’t cover air bricks). Some of the longer spans make the crockery ‘jiggle’ when my kids stamp on the floor. Probably could have been improved with smaller spans but we are going slab this time.

My makeup: walls - brick and block, 200mm cavity eps blown beads a- 0.15 u value floor - 200mm pir (two layers of 100mm) - 0.09 pitched roof - 304mm posi rafter, cellulose blown insulation with 22mm wood fibre sarking and medite smartply as inner airtight and vapour control - 0.11 u value flat roof - warm roof, 200mm PIR over 225 posi joists with medite smartply again - 0.10 u value SAS aluminium windows and doors average 0.75 Uw value SAS sliders and bifolds average 0.9 Uw value MVHR throughout wall hung floor posi joists with passiv purple around hangers (just in case) aerobarrier throughout target 0.6 ACH ASHP with downstairs UFH. Currently deciding between fancoils upstairs or traditional rads with AC units for cooling. Spent a fair amount of time detailing the above and I think it represents a high performing traditional masonry buildup. Would be wary of things like PIR in your roof. Whilst theoretical u value is 0.11, I doubt this would be achieved unless you’re all over fitting. And even then wood shifts and gaps open up. Opting for things like pumped beads and cellulose designs out any potential issues with workmanship - even the most diligent builder might have a crew on a Friday afternoon that rushed something. You’ll live with that Friday afternoon job forever. Have a look at your thermal junctions as well. Make sure where your roof and walls meet is continuous for example (beads and blown cellulose work well for example here). Check or design your thermal junctions at doors (thermally break across your cavity for eg don’t use concrete fill cavity to sit your doors on. It’ll bridge. ) Learned a lot on last build and have tried to design out my mistakes from last time!

Congratulations! Appreciate @Alan Ambrose’s points but from my experience the conversation between planning officers and planning consultants is fairly reliable. I would say if they’ve indicated they will pass it, your parish council were supportive and you didn’t have any pertinent objections it looks like a reason to celebrate. I remember the feeling, so savour it and get ready for the hard work! 😂

Why did you get the a2a? For cooling?

Does your a2a supplement an ASHP or is it your sole heat source?

Agreed. We’ve already decided to use aerobarrier for the interim testing and then the actual sealing. They work for me the client (often the testers are getting whatever the builder needs them to get) so we will have this check and balance to ensure we get the level I’ve designed and want to achieve.

Have you picked a fan coil unit? also - what happens if the units are cooling and then the DHW program starts?

Thanks @joth do you have fan coils yourself?

Does all flow and return pipe work need lagging as well if running cold water through?

Pretty much as title says.. considering fancoil rads for our upstairs again instead of a ducted AC system… would like to use them for cooling as well. Does each fan coil need a condensate drain for cooling?

Agree to a certain extent @TerryE but a 90k price differential? That’s a lot of spare money to spend on airtightness detailing.