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exact same level of insulation and floor build up/finish as the rest of the house. It's all getting done at the same time.

yes. thought it best in case that ever changed at some point to a habitable room. Plus I often work in there, so saves me firing up a heater.

Thanks all for the comments. Looks like some of the base units in the kitchen area will contain food, but as I don't know which ones yet think I'll play it safe and just leave that area unheated. Got the final plans through from Wunda and aside from a phantom door (circled in green) which isn't in our house, they've put the pipe everywhere in the small room at the front. Here there's just a washing machine and small unit for a wash basin. Worth veering round those 2 or just go under?

We have a polished concrete floor being installed in July so next month have to install the UFH. Had a design completed with Wunda and they have omitted any pipes under the kitchen units/fridge freezer etc. As it's a polished concrete floor, and expecting to be running low flow temps would having it under the units, fridge freezer have as much of an adverse effect on those appliances? My thoughts were that the heat would end up underneath them anyway as it's all being poured as one slab. So just wanted to gain and advice from here as to whether I'm on the right track and have the UFH everywhere? For what it's worth the fridge freezer will be a free standing unit.

An update to this thread. Bit of a u-turn but we've ended up booking in a firm to provide a polished concrete floor finish. They're also going to pour the concrete. Architect noted my area had a 2-3% chance of radon so suggested to keep BC happy install a radon barrier after sand bind. so build up now is: 150mm type 1 50mm sand radon 175mm PIR dpm ufh pipes stapled to PIR 125mm concrete Concrete firm install a193 mesh and use fibres as part of their work. SE is satisfied the compressive strength of the PIR will support the concrete. Is FI5000 PIR worth using over GA4000?

Thanks for all the replies. I've fired off the floorpans to a few companies and will see what they come back with. If the supply vents could come out of the wall I could run a duct beneath the ceiling (above the wall units), from the blue x on the ground floor and in the direction of the joists. Attached an image to make it clearer. Green x would be the supply vents. As for an extract vent by the sink (reply by @Marko), I possibly could get a vent beneath ceiling and above the wall units/extractor, then come up into the ceiling and over to the sink, but would depend on the height needed within the ceiling void for the extract vent. Don't think I'll be able to get a extract vent to the WC on the GF so maybe just go for a standalone unit in there.

Joists are solid. i will have access from the ground floor as existing plasterboard all coming down. so currently due to the floor build up for the first floor UFH I have approx 75mm space left, however I could increase this to 100mm with some baton.

house is 1970’s semi detached. Has 55-60mm cavities which have recently been filled with eps beads. Loft has 250–300mm insulation. New aluminium windows and doors, all installed with me508 membrane, air seal foam, compriband. ufh is at 135mm centres and sits on 100mm PIR and covered with 25-30mm dry screed. On top of this is t&g boards and aside from the bathroom this is topped with thermal stream underlay and a low tog carpet (total tog 1.8). In the bathroom 6mm hardie is on top of the t&g boards, then ditra mat, then tiles.

Apologies I should have been clearer. in ground floor, floor plan; blue ‘x’ is a small opening from ground floor through to the loft. It’s open at present as it’s where my flow and return for first floor UFH go up, along with h/w. blue arrows are direction of joists. green ‘x’ is location where a grille could definitely go. green ‘x?’ is a possibility. on first floor plan; blue ‘x’ is the location of the gap from loft to ground floor. red ‘x’ is where the bathroom grille would have to go. This is due to bathroom ceiling is solid surface and grooves for extractor already routered in. green ‘x’ is where definite grilles could go, with no restrictions on duct size as that would be in loft.

Can anyone help with a design for MVHR in my home? I've attached a floor plan of both floors with 'x' where ducting could be fed to. Size of ducting for the first floor, can be what's suited as not restriction to size in the loft space, however on the ground floor I'm restricted to a max height of 75-100mm due to UFH already being installed between the first floor joists. Location of the main unit could go in the loft against an external wall for venting in/out through there instead of the roof. Thanks

Does anyone know what the w/m2 output is of UFH at 135mm centres in a pug screed? And for what it's worth this is under ply T&G boards, and underlay and carpet (total tog 1.9). Had a check on the Wunda site and they don't specifically list the output when using carpet, just a generic figure.

My builder has come to the point of making the connection between a new waste run into the existing sewer run. He plans on using a plastic 3 socket 90° tee with flexi couplers. However after a conversation with Anglian water's drainage department today he's been told that he needs to use a clay y branch, then a 45° piece before connecting up to the new pipe run. Has anyone ever heard of this? In particular using a clay y branch and 45°? He's a bit puzzled as to why this is the case and is going back and forth with their technical department to get clarification. This is slowing down the build so thought I seek opinions and experience from here. Thanks

Can convert easily enough to 22mm so will get that done. After the softener, and manifold, I'll go into the inlet control group then into the cylinder. I could put a PRV before or straight after the softener so that the cold going to the bathroom, as well as what's feeding the cylinder is all the same pressure?

@JohnMo perfect. thank you for confirming. One thing I have noticed, but haven't paid much attention to till now, is that once the water mains comes into the house there's an adapter and its reduced to 15mm for the stopcock and so forth. I'm guessing that as I currently have a combi this isn't so much an issue, but going forward with an ASHP will this be. Would it be wise to run from where it comes into the house in 22mm? Connection on most of the cylinders I've looked at appears to be 22mm for the cold water inlet and also the DHW. I can always reduce down to 15mm, but I'm assuming sizing up isn't really a done thing?

With regards to the connection onto the CU I've got blank spaces so no issues with having a dedicated circuit. In fact the current oil combi is on its own circuit so I assume sparkie will just replace that. @JohnMo My initial plan is from the cold feed into the house to tee off to the a manifold (for the fridge/hot water tap and heating circuit via the filling loop) and to the water softener. Then out of the softener it goes to another manifold which will go to the cylinder and to the bathroom. Already got these manifolds in the bathroom as a means to have isolation as all the pipework is behind tiles. Done it all in plastic to not have any joins. Sound ok?