efkor

Note that the Screwfix blurb says it can only be used with copper pipe BUT check out the single review .... a self builder has commented that he has bought this item and that it can be used with push-fit plastic

The eaves of the extension (any roof type) cannot go higher than the eaves of the original house. Prior approval is for rear extensions, but note that the 8m you quote is for detached houses only. If you need more info, I have done a whole series of Permitted Development videos that some Buildhub members have found useful (youtube/efkor)

@phykell thanks for recommending my Permitted Development videos. In a previous life I did some planning consultancy, submitting appeals on dubious planning decisions. Nowadays I lurk on BuildHub when not progressing my own selfbuild

Correction ... I can't get 5 x 60m runs out of 3 x 100m pipes

Some great points have been made. JohnMo, I agree with everything you say ... a wireless thermostat gives flexibility on final location ... dump the floor probe and the isolation valve (no idea why they were included in the quotation) ... and include a good mixer (probably a wise add-on). BotusBuild, you are so right, I can't get 5 x 60m runs out of a 300m pipe!! Good spot and JohnMo picked that up and suggested 3 x 100m loops and a 3-port loop. You know what, I can rejig the design and so that works for me! John Carroll suggested 2 thermometers to monitor the flow and return temperatures and I think they will be useful, giving some confirmation on the system efficiency. The only idea I'm not going for is putting the manifold in a cabinet because I'm more than happy seeing rows of gleaming pipes and manifolds in the plant room!

There are some truly sophisticated UFH setups described here in this community. However, I have taken on board the wisdom of those who say that a passiv style house does not need such wizardry. My thermal blanket is a minimum 250mm on floor, walls and roof and I am tying the UFH pipes to the nominal 6mm mesh in the non-structural 175mm concrete slab. UFH is only on the ground floor and towel rails/shower mats will be electric-heated. (I've gratefully borrowed lots of your implementations!). As Wunda have got multiple thumbs up from you, I asked them to quote for the simplest solution (no actuators) of 1 zone and 5 loops of around 60m each. This is their quote: 1x 6 port manifold - £134.95+vat 1x Wilo pump station - £179.00 1x Isolation valves - £10.00+vat 3x 100m 16mm pert al pert pipe - £177.00+vat 1x Standard hardwire thermostat - £25.00+vat 1x Floor probe - £5.00+vat 1x Pallet Delivery - £30.00+vat Total including vat = £673.14 I'm very pleased with both the price and the speed of their response. I'll fit the kit myself and ask my electrician to wire it in. I'm just wondering if you can see if any bits are missing off the list.

Thanks Norbert. The MD of Eden Insulation (Steve)) did ring me later and was apologetic about the absence of a response due to holidays, working on site etc. He did offer a tour of the workshop which I may take up

I totally agree, Steamy Tea. Finding repeat items in a self-build seems a rarity and they should be enjoyed to the full!

Thanks very much everyone for your comments. If I hadn't already spent 4 months on getting my SE to produce drawings, I might be looking seriously at switching to the portal frame solution of Gone West. And looking at the impressive i-beam structure from IanR, I can see what is possible. As you say Ian, the connections are just different to the solid wood connections. A good question raised is why I am making cassettes onsite instead of doing a stick build. The reason is connected to the fact that I am a solo builder and I have a 2-storey brick house that I am extending upwards, back and sideways into a 3-storey house. To enjoy the build process, I will fabricate the cassettes precisely in the ground floor "workshop" away from the vagaries of the Cumbrian weather. After creating and storing all the cassettes for the ground floor, I will then enlist a couple of helpers for one day to erect them. Repeat for the other two storeys. And how do I get the cassettes up to those floors? I've bought a used half-ton hoist (£600) and installed it above the (removable) stairway. And moving the cassettes around is achieved with used heavy-duty skates (all my kit is purchased from BPI the online auction site). Consequently, the cassettes will have maybe 4 or 5 times the number of connections that occur in a Gone West or an IanR type structure. On reflection, with all of the extra work required on connections and packing the voids (there lots of 2 and 3-ply also) I think I will go with solid timber and take the hit on thermal efficiency. My wall insulation is 175mm stud plus 40mm EWI and I think the cheaper solid beams will subsidise the cost of the EWI. By the way, Norbert, I left phone messages with Eden Insulation last week and received no reply. I drove to their premises in Appleby this afternoon and the office/workshop was closed up. Maybe they've gone out of business? They have a great product ... I hope that they stick around.

Sounds like good pragmatic advice... when my TF designer said there's no problem in designing cassettes using i-beams, he was probably referring to work he's done for building firms. Maybe he wasn't considering the buildabiliity of it for a novice self builder like myself. I've seen the connection details in the JJI manuals and they are scaring me off a little. I might give myself a break, just do a "normal" cassette with solid studs, enjoy some straightforward nailgunning me-time and save the brainwork for other technical stuff, such as ASHP, MVHR etc

That's very useful, thanks Adrian. I see how they have minimised the number of troublesome i-beam to i-beam connections that are so prevalent in a cassette. They use a portal frame structure and hang the floor cassettes from the internal face of the 2-storey wall. Unfortunately, I can't use a portal frame solution on my site.

Yes, stick build is an option but the problem of the filler plates and the awkward i-beam to i-beam connections still remains

A buckling analysis is another reason to avoid the i-beam solution Adhesive bonding is way less fun than nailgunning!

@mikesharp01 Your comment confirms my fears!

Hi, I'm on a first-time self-build in Cumbria and I have am about to instruct a timber frame designer. I intend fabricating the wall and roof cassettes myself and I'm unsure whether to replace the dimensioned timber studs with i-beams. Reasons to use i-beams are (1)reduced cold bridging and (2)avoids wrangling with bent/twisted timber. Initially, I was just going to replace the inner studs with i-beams but my TF designer says that I can replace top and bottom plates and the side plates too. He mentioned that I would have to add packer plates and that the window area would need to be boarded in ply. He didn't elaborate on fixings but I'm having trouble imagining how I'm going to nail up a cassette made entirely from i-joists. I've seen angled nail-plates in JJI brochures but this leaves me none the wiser. I've seen that a few of you have used i-joists. Can you give me some pointers on connections please? Or should I just stick to replacing the inner studs. Thanks for your help