ChrisInKent

It also matters if you’ve got the cash to build it in full, need a mortgage on it now or in future or need it to be an asset you could sell if you had to. If none of that matters ignore the rest below. If you need to sell it would it be mortgageable or require a cash only buyer? Our timber frame with 100% metal cladding reduced mortgage providers to 2. Look at the challenges Colt houses have selling just 60 years later - cash only. Will a mortgage company believe the 100-200 years or be totally risk averse. You can build anything but it’s whether you need it still to be an asset in your lifetime or not and can persuade lenders of that.

+1 Used this on a softwood cladding 6 years ago and it still looks good.

We’ve just got the house structure up so not ‘post build’ in any way but I would: - work out services costs and soil conditions pre purchase. Yes an expense but it could have given us leverage to get the land price down a bit (clay required piling, no easy route for services) - look every company up on Companies House. Nearly got burned twice by companies in liquidation - trust my instincts more, not use anyone who I don’t like when meeting them - make sure everyone understands what we are aiming for, is invested in it with us - go local whenever possible, didn’t do this with TF company and are happy with that choice but we are using as many local trades as we can now. They have reputations to protect where out of area trades don’t - apply for the services sooner, it’s a year in and we’re just about to get power (hopefully!), another month for water…

Pleased to say they have refunded the £s.

We went with Rationel Aluclad windows and doors. We like the chunky frames but I know others might prefer as thin a frame as possible. Only thing we were dissatisfied with was the packing protection - no film on either the aluminium or the wood so very challenging to handle when fitting. But I’m not sure if any other companies protect them either, maybe they’re all like that?

I’m sure ASHP size will come down further once we have done the air tightness test and taken the plumber on the PH journey… he’s open to adapting the design once he understands the impact of MVHR AC/h, the other company wouldn’t.

A bit of an update. We couldn’t get the original company to change their design or explain their rationale. We went locally to an MCS accredited recommended plumber. They have designed a 2-Zone UFH solution which we are happy with. Our house has a couple of living areas upstairs (not just bedrooms) so we’re having UFH on both floors. The redone heat calcs show we’ll need a 7kW ASHP no buffer required rather than the 10 or 12kW ASHP with buffer the original company was pushing. We are feeling more confident that the system is suited the house and we’ve got a local plumber, who is working with us not against us.

Thanks for sharing the stats. Just wondered how many sqm is your house and what size ASHP you ended up with?

JCB Insurance were recommended to us but we never used them in the end - our ground worker hired the Telehandler so it went under their insurance. There’s lots you can’t control on a build but having the right insurance seems a no brainer to me. I wouldn’t risk not having it.

Our building control/plans specify 160mm for the floor at 0.022 which most of them are, but it can be in any combination. Only one company does 160mm but quite a few do 150mm so it might be worth checking why you need to have 2 layers. I’ve found it’s worth doing calls for different combinations to work out the cheapest combination. So you might want to do 60/90 or 80/70 if you are allowed to get the cost as low as possible. Has anyone used Pinks Insulation or Trade Insulations as a PIR supplier? Or got a recommendation for good insulation suppliers ( need deliver to South East England)?

I had a look at the Part L info but can’t see this prevents 2 zones being used. The clause (5.20) says one thermostatic control per room but goes on to say heating may be controlled for each heating zone rather than individual rooms ‘where justified’. In 5.21 it says justification includes where ‘2 adjacent rooms have a similar function and heat requirement’ which I read as allowing me to treat the ground floor living areas (kitchen dining living utility) as one zone as we want them all at 20 degrees.

Non refundable

Sorry @Chanmenie I should have written it as 4.5 watts. We are going to be 200m2, super insulated, taped to less than 1.0 air changes but aiming even lower, triple glazed, MHVR system which aims for 85% heat recovery, 160mm insulation on top of the beam and block/membrane under the UFH and then a 100mm polished concrete floor over the UFH.

Yes their design is a thermostat for every single room. we are using an ASHP for heating and DHW. Same company refuse to use less than 1.0 air change in their calculations as we haven’t proven it yet (house isn’t built yet so they are using 2.5 to calculate) and won’t factor in the MHVR either so that’s been causing alarm bells. We are planning close to passive. I calculated heat loss 4.5 and they are quoting for a 10 or 12W pump. They said they might include MHVR at 50% heat recovery (we’re expecting 80%). Wondering if we should cut our losses and start again…

I’m after some advice please on UFH. After reading this forum we asked the UFH company we’ve been working with to revise their design (which we have paid £100s for). We asked for a simple 20 degree zone for living downstairs. Their design had each room with a different temp from 18-21. We also wanted an 18 degree zone for upstairs (bedrooms). We’re not bothered with warm bathroom floors which their design had at 23 degrees. So the ask was for 2 zones instead of 10-12. They have come back with a no, they’re happy to install as designed and then we can change it later if we want. Their rationale is that the design follows certain principles which allow them to provide the ongoing warranty and support, a 2 zone system wouldn’t be possible to do this. Does that make sense? When others on this forum talk about 2 zones do you in fact have multiple zones running at one temp and multiple others running at a different temp? is a 2 zone system possible?