Conor

Aye, local ground level. You can of course, alter the hight of the ground if required...

Is a nighttime tarrif an option for you? Consider that and do most of your car charging and hot water heating overnight. That should cut your bills. Then your PV will cover your daily appliances and dump excess to your hotwater. It's what we're doing. We're down to about £1.50 a day now.

Go with what the planners will dislike the most. E.g. if the issue with precious application was render, include render in your plan. This means if you change your mind and want more stone, wil be less of an issue getting it passed as a non material change. Our architech included porches, overhangs, railings, balconies, garage etc that we are not likely to build... But as he says it gives us the option.

You'll easily get down to 1.5-2 with your current approach plus a few basic extra steps: 1. Air tight tape around windows and doors (from frame to inner block). Don't forget the door thresholds. NB compriband is an external weather sealing system to close the gap between the window frame and outer brick leaf, and won't do much for your airtightness. 2. Block up any conduits and penetrations through the walls / roof. E.g. conduits to external wall lights, get the spark to fill the ends with acrylic sealant when doing second fixes. 3. Foam / tape around all penetrations, e.g. waste pipes through the subfloor. Use foam for big gaps, then trim back and paint / tape. 4. Roof structure... You've not mentioned this yet and is the most crucial one. you'll need a membrane or other taped solution. We just had our airtightness test done and it appears almost all of our leakage is through the roof structure. Unfortunately it's now impossible to rectify as we're baorded and painted. 5.. Most effective one... Let all your trades know you are aiming for an airtight house and not to go leaving holes everywhere! It's basic build quality. 6. Have rolls of airtight tape and a tub of paint on hand so you can quickly deal with anything you spot. E.g. we had to paint along the entire wall plate and under the windows. Paint is handy for things like bolts, hangers and around timbers than penetrate the wall. To be honest, your architech should be the one guiding you on all of these. They should come out as the build progresses and advise. One last tip, get an airtightness test done before second fixes so you've a chance rectify any issues. I look forward to you posting here in a few months boasting about your airtightness test result 🤣

No. Stick to rads. Would be a criminal waste of energy. Only other thing I can think of is to remove the existing floor structure, clean up the slab, put down a DPM, 100mm PIR, UFH and 50mm liquid screed (assuming you've got about 150mm depth to work with). That would just about do.

Forget the PIR and use TLA. We had loads of variation and had steel beams to deal with as well. Didn't work out that much more and saved a load of labour.

It's just short of double, depending of its white or grey EPS, and density. It's about 1/4 to 1/3 price of PIR so wil always work out cheaper, and you'll save on hardcore and labour. You'll want 300-400mm of EPS.

We've 50mm cement based liquid screed. Solid and flat. Can't ask for much more than that. I think a lot of the thermal conductivity stuff is marketing hype from the sellers. Get the thinnest coverage product and maximise your insualtion. The more insualtion you have, the cheaper it will be to heat the house.

Have some good news for you. We had exactly the same scenario and I grabbed an open reach engineer that was installing a new fibre line to our neighbours house (there a pole serving about 6 houses right at the edge of our entrance). I asked him about how we'd move an existing copper cable to our other neighbour (too close to our roof) and getting a new ducted line to our house instead of the original overhead copper cable. Basically he said, prepare the duct to the base of the pole with a draw rope, go and apply for a new fibre broadband contract with any provider, open reach would then be sent out to install the new cable and would likely be able to use the duct provided. Same for moving the neighbours overhead cable. Says it's the cheapest and fastest way of doing it.

Wastage is dependent on the complexity. Wastage from our first floor (vaulted ceilings, multiple angles and opening) was huge - basically a full skip. For the basement it was barely a small trailer load. Simplest way is to measure the gross Wall area - including windows and doors and you should be pretty close. If you are buying it now, make sure you have somewhere indoors to store it. We had 20 odd sheets outside on a pallet, covered in breather membrane, DPM etc for a couple months... Lost a few sheets to damp, negating any savings.

Not quite the same, but our joiner is a big fan of using strips of dpc for shimming out timber in door frames, joists etc. Can be cut easily to whatever size and don't compress. If you don't want to pre drill the battens, use partially threaded screws.

Our bco required either pink boarding, fire paint or double standard boards. This only applies to structural steels that support a means of escape from the building (so roof ridge beam excluded)

We had to do a ground beam over an old well. But was done using rebar. As far as a I can remember it was 450mm deep, 600mm wide and a good 4m long (under the planned 200mm slab) with a rather large rebar cage and then poured with the same C35 concrete as the foundation slab. Think it was an extra £450 in labour and materials. Ask your engineer if this is an option... Not sure it'll be any cheaper though as rebar is way up in price.

We ply-lined walls to be tiled.

Fill the loops and pressurise and most of that will drop down. Is it on top of insualtion or concrete? If insulation, hammer down some staples at the bends won't take long.

Get 3g pcv windows. When we were looking for Windows we saw some pvc windows with nice minimal profiles and in a massive range of colours and looked great. About 50% less than aluclad and the same performance. Cheap wooden windows would be the last thing I'd buy.

What's the cover from the pipe to surface? Normally you'd backfill with lean mix concrete if cover is 400mm or less. Is this a perforated or solid pipe? Twinwall is pretty damn near indestructible. I stuck the digger bucket in to a section the other day and it survived. Nice and bendy, PVC shatters.

We're planning on 900mm wide, 100mm deep poured concrete paths around the house. This will include our front door ramp and covered porch. This will eventually be paved with 40mm granite pavers. Probably not bother paving around the sides of the house so will set levels accordingly. All of this sits on the loose, clean stone backfill (50mm stones) that surrounds our basement. I'll put down a layer of geo-membrane on top so we can have a 100-200mm or so of compacted type 2 or 3 before the concrete. I'm worried about movement and cracking.... So thinking a393 mesh and movement strips. Is this sensible or overkill? Is there a cheaper way? Edit- A252 mesh is £40 cheaper per sheet (£80 Vs £120). Is this good enough for crack control in this case?

Consider getting an induction downdraft hob. I don't know if you've used one or not, but so much better than gas. If you're committing to gas, I don't think you've many options for downdraft. Your ceiling mounted flush extractor is what I'd go for. Your MVHR will catch anything the extractor doesn't.

Your electric supplier will (via the DNO) install a new digital meter for you when you apply for a contract to get export payments. Mine was swapped the other day.

Is the insulation EPS? We went for a renderer that used Sto. It's fantastic.

Telehandler is the obvious one. Either that or precut the rolls in to roughly the lengths they need to be. What's your existing scaffolding / access setup? Photos?

Thanks everybody. I've found long radius 22.5 and 45 bends and my local builders yard. Because of the distance I need a chamber regardless (need one every 20m) so I think I'll put in the bend just downstream of a standard chamber. I'll skip the chamber for the second bend as it's right before the last MH anyway. Seems to be the best value and fastest option... Only got the digger for the weekend so don't want to spend half a day benching and building chambers!

I've a long single run from a secondary soil stack to our main chamber at the public sewer connection. It's about 40m in total. First inspection point is fine, 90° bend where the pipe comes out of the building. From there, I need two more, one will be. A 45° bend, and the other a 22.5° bend. I can't seem to find any dedicated 45° single run inspection chambers. Would I need to fork out for a standard 3 or 5 way entry chamber? Or can I use a straight through chamber and just have the bend immediately downstream?

We built all our internal walls off a course of aerated blocks. Stud and block walls.