Mr Punter

In the in England it is covered by Part K 5.4.

Why not continue the flat single ply roof out? You could accommodate the change of pitch and keep it as a proper warm roof. That is a very shallow pitch for tiles.

I love the look of a cut string staircase.

Door closers are no longer required for 3 storeys. Did you end up with internal drained cavity membrane, or was there a simpler solution? That was a big hole you dug, especially as the site looks fairly flat. A friend had a house with a deep basement, part of which was a swimming pool. The neighbouring house made theirs into a squash court!

It is because they are more likely to be damp, flood prone, dark, poor mains drainage for WCs etc, difficult emergency escape and badly ventilated. I don't understand why the valuers were keener on a basement than a 3rd floor unless the third floor was badly compromised with sloping ceilings and rooflights only. My experience is a basement is valued at no more than 80% maximum of upper floors and only then if it has good natural lighting and access.

We did a basement and used king piles - drill a hole every 1.8m with an auger (maybe 1.5m lower than the excavation bottom), lower in a steel h section, concrete the bottom 1.5m, as you excavate, infill between the steels with rail sleepers (which can be removed later). The more critical bits, where there were adjacent buildings, we did augered holes and filled with concrete to create a sort of secant piled wall. It meant we had a safe working space between the outside of the basement walls and the face of the excavation. Basements are a substantial risk and cost. I have experienced higher per metre build costs, while the space created is worth a fair bit less than above ground.

Not sure where you are with this but for the permanent supply it is preferable just to have a single length of pipe from the meter to the stopcock inside the house, with no connectors. Even if you have a temp supply to the caravan I would run to the house separately and reconnect. Also some people go for 32mm instead of 25mm but please don't ask me why!

It would be really helpful if you could post a picture so we can see what the current windows look like. Crittal did a lot of metal windows between 1930 and 1960, but as you are looking at Accoya I assume the current ones are timber.

This https://www.rightmove.co.uk/property-for-sale/property-76396397.html Is nearer to the size

I had a firm replace an asbestos garage roof with a double skin metal insulated roof. It was en-bloc and staggered up to the one neighbour and down to the other. They measured, removed existing, installed, provided extra bearing where needed £1,600 plus VAT with an asbestos disposal ticket. They had to move some of the crap in the garage. New roof is safe to walk on and no condensation. With the floor I just put down DPC and laid 18mm chipboard flooring over £105 plus VAT diy. New Hormann garage door £435 plus VAT diy fitted. Overall, £2,140 plus VAT for the upgrade, but now I can store everything in the dry and it is secure. Single garage

Depending on soil type, you need up to 30" (750mm) of post in the ground. Posts tend to fail and rot at the ground level junction, so when you concrete in, bring the concrete up past finished ground level and haunch up round the post, so that water runs off.

The chords look a bit thin for the 12mm fixings to get a good bite and some of them will probably hit the metal web. Because the whole of the channel would need to fail, you would notice that the glazing seemed loose before it became critical. In this location you are not likely to get a large number of people squashed up to the glass in the way you might if this was a balcony, but you need to consider the risk if, say, a future owner lets this as an AirBnB to a stag party.

Shame that last joist is not a glulam or LVL. Are you planning on plasterboard to run up to the underside of the glazing channel? I think with channel you will need a continuous sheet of ply as the fixing will probably only just get the bottom edge of the top chord. You could look at the stand-off type fixings instead of the channel. Are you going without handrail? Although it looks sleek it is not comfortable, although it will mean that it does not get approached or leaned against much.

Aluminium is often powder coated and is very difficult to re-coat. I did enquire a few years ago when we were looking at an office to convert to resi. The place had a lot of blue powder coated windows and we were able to get a quote to have the colour changed, so it is possible but quite expensive.

I use the Screwfix fire rated stuff for all my foaming needs. For no expansion, do you need Gripfil type stuff?

Never heard of it. Is there a downside other than cost?

I suggested Celotex as dormer cheeks are often a lighter weight construction than the main walls - maybe 89mm - so sometimes the extra insulation can help prevent a cold spot. If you are planning on the render being continuous from blockwork to render board then you could look at stainless eml over the render board with a big lap onto the blocks or an expansion gap bead between the 2 materials. Another option may be to tile hang or lead clad this bit but it may look a bit crap.

Our local recycling centre charges £4 a bag for soil and hardcore and £4 for plasterboard maximum 1800 x 900. Apparently there has been a huge increase in flytipping since they introduced this.

I really hate it when trades decide to dump some of their own crap in my skips. Or the ones that just launch whatever rubbish they have, filling the skip with empty cardboard etc or every day, carrier bag with empty plastic bottles with lid replaced, sandwich wrapper and newspaper. On my last project I made sure all cardboard was flattened and stored in the dry. We had a firm come to collect it. We also had a local wood recycling firm collect timber, pallets etc. Still had to pay but half the cost and at least it is being put to good use. Plasterboard went to a separate skip.

From outside render, renderboard, 38 x 50 counterbatten fixed with long screws through, membrane, Celotex - thickness to suit, existing timber frame.

Do a test area - like a WC or just a corner. Unless the concrete is dusty or polished there should be no need to scabble. Maybe try a different self level compound and / or primer / PVA.

Looks like a super location. What style of house are you building? Any chance of you doing a blog?

It may be that it is outside of building regs but there is still a requirement that it is structurally sound, particularly if it poses a risk to people or property. That is a very large wall. I think you should ask a structural engineer to take a look and report back to you with the cause of failure and the most economical remedy. Perhaps your buildings insurance will cover repair or rebuild costs. Check the policy wording carefully.

Hilti gun. Maybe a bit of car body filler needed around New Year.

Should you run a course of brickwork around for the bitumen to dress up, or does this upstand get done in timber? Make sure the detail is OKed by SIG. I used adjustable pedestals from Castle Composites but the minimum height is 30mm. They also do fixed height ones down to 10mm.