Mr Punter

If you have a decent SAP person you will pass. There is no test at the end other than airtightness. Sometimes using different lintels can help the SAP rating for thermal bridging.

Hello @Buzz. You have come to the right place. There is loads of useful information here. Do you have a construction type in mind? Where about are you located? Are you going to be fully hands on?

I go for about 10mm and I rest the sheets flat on a bit of insulation. I have tried the only just through and it doesn't seem to cut as cleanly.

I prefer medium density aggregate blocks. They are inexpensive, easy to fix to, easy to render / plaster. Have you worked out the difference in heating costs with the aero ones? I suspect insignificant.

@Hilldes can you post the BBA cert as I cannot find it? You should have DPM / vapour barrier on the warm side (top) of the insulation.

You are certainly a perfectionist and you are at least aware enough to see that it is not reasonable or great for your mental health to be so particular. Most people - especially men - obsess about things in a slightly irrational way. Lots of things that happen on site are far from perfect and you are certainly not on your own when it gets to you. Maybe drink more so the shoddy work looks more bleary? Works for many on here.

What you had on the drawing looked fine. Quite why you are looking at 190mm concrete I have no idea. Polythene over the insulation. 75mm concrete with mesh 25mm from bottom would normally work. Ties the pipes to the mesh. How much is the floor costing?

Unless the made ground is overlying clay there should not be heave issues. Ask them why they are included and if not required you could deduct the cost.

About 55%. Depends a bit on if you first fix inside before. Also you may have a timber frame with windows and roof fitted but no brickwork / gutters etc. Service connections can be costly.

I had a request from someone to connect drainage onto land owned by us, where the local water authority showed their pipe on our land. We had our own development plans so declined to allow them and after much sulking they did a pumped connection some 75 metres long. Had we agreed it could have really curtailed our plans and we may have been responsible for any damage caused to their pipe. They may also have been able to access in the future for maintenance / repairs which would have been unacceptable for our future purchasers.

I now live in a new house and it would easily overheat with an Aga. No heatwave required. So will yours if it is built properly. My Aga was in a cold Victorian detached with solid walls, so it was nice to come home to.

I have had one of these and I would advise DON'T! Sweltering in the summer, crap to cook on, expensive to run.

Another vote for option 5 rev A. Perhaps replace the door with a pocket door if it will mostly be left open. Replace the table and chairs with a fixed banquette 1800 long back to the wall 500 in from the end wall. You could do the smaller room size like option 2 if you wanted. You may get the sink on the same run as the hob with the larger room option, then you could try @AliG's run of tall units. Keep the peninsula but move it towards the folding doors so there is 1000 between end of worktop an end wall. Keep the worktop all the same height.

The photo shows stuff that looks about 5mm thick. Normally screed is between 30mm and 80mm. Yours looks like a levelling compound laid over an existing floor. Dig a bit out and see.

Is this the only eating area? As others have said, you would need min 1000mm between the island and other run. You will be hurdling the dishwasher door as you have it. Options 2, 3 and 4 you cannot get to the folding doors unless you reverse them. This is worth a lot more fiddling with to make it work. Is the sink waste catered for?

Can you fit a non return valve on the pipe if it is liable to surcharge?

Had you been more specific in the OP than and I would not have commented as I did. Are you interested in house size, planning issues, orientation, access and parking, energy efficiency, profit and end value? If you ask a specific question you are likely to get more targeted answers. You seemed to be inviting general comments, which you got.

That is right @Moonshine. Even some of the self builds here sail close to the wind, but the HSE normally only get involved if there is a serious accident, a death or a report of dangerous practice from the public or other bodies.

I would want the plots to be separated with no shared driveway. I would not want neighbour vehicles turning in front of my house. All of the design and construction work will fall within CDM regulations and it is your legal duty to comply. You must have a Principle Designer and a Principle Contractor. I assume you are VAT registered?

Who supplied your front door @HerbJ?

You normally have compressible material in the movement joint. The render bead sits centrally on the joint with a wing either side fixed to the substrate. There is no big issue with the bit of brick. The gap could be filled with mortar, render or whatever.

Is it possible to dig a trench on the other side of the foundation and fill with shingle like a French drain to divert the water? With the joint, have you tried CT1? Otherwise could you loosen the screws and put rubber strip under the timber?

It don't see why the existing cannot be safely built over. I would want to know that the OSB or ply on the existing was thick enough to hold the proposed screws. The new firrings need to be very well fixed down, then the new OSB or ply would be best fixed through the firrings, so some very long screws needed near the apex. There is nothing wrong with having the additional void, as you always get one with firrings. I think it would just be a waste to scrap what is there.

You may as well incorporate dormers. You will need a scaffold temporary roof. The trusses will be big and heavy.

The tiling and flashing needs to be complete to make it weatherproof.