Mr Punter

Nice neat benching.

All the drainage looks really deep. Was the system designed? Shallow can be a lot easier to install and maintain.

I would just use a couple of 30 or 45 degrees and pipe between.

I was looking at this a while ago and had Passivent on my shortlist as well. They did a system where the vents in the rooms reacted to the local humidity. It looked quite clever but I just went with standard extracts in the end.

The Egger Protect you are using is fine for bathrooms - better than green chipboard.

The silane based wood floor adhesives work on most substrates. You do not require underlay, the blocks need to be fully stuck down. Ask the adhesive supplier for advice. It is expensive stuff. Wood blocks are easy to mess up, so do your research and prep.

My favourite would be D4 glue on joists and all board edges and a few Paslode nails to hold the boards in place. Leave a perimeter expansion gap. Fit screws after you are watertight.

Just off the M4 heading in to Wootton Bassett.

It looks like the single switch (above) is to isolate the transformer (below) so you could switch off the consumer unit power, remove the wire from the switch that leads to the transformer, then switch power back on.

Check the sizes as if they are tall they may not go under the garage door, especially on pallets. My preference would be to prepare a flat area with type 1 and drop the pallets there with a forklift, cover with tarpaulin until you are ready to fit. Once you take them off the pallets they will be more difficult to protect.

I have used a couple of TF firms just doing standard 140mm kit. It comes down to what spec you are looking for and how much they do. If you want it to be fairly risk free, perhaps look at MBC Timber Frame, who several on here have used. They give you a guaranteed airtightness on completion and a variety of frame types to give varying u values.

You don't need ventilation with a ground bearing concrete floor. You do need at least 100mm of insulation if it is Celotex type, 150mm min if expanded polystyrene. Lovely and warm and dry.

Squaredeal do the Hardie cement board stuff https://www.squaredealupvcshop.co.uk/product/smooth/

Hi @Field_of_Dreams and welcome. It looks a very good candidate for timber frame. You could get a firm to supply and erect the superstructure so you have watertight fully insulated buildings that you can work on at a pace to suit you. Simple erection with a telehandler. Perhaps get a few quotes for comparison?

Not needed, but nothing to stop you. You will obs need some more timber where the wall on the left is flush with the truss.

If this is still about soakaway sizing, just use the calc I gave - 1m3 for each 60m2 of plan area. Does not matter what sort of roof goes on, just length x width. The stuff about the roof slope is just for gutters and downpipes, not soakaways.

What centres are the trusses on? They look more than 600mm, but maybe that is a trick of your 'special' camera. If 600ctrs you can just use 15mm plasterboard.

These are really heavy and awkward. I could not lift one on my own. We did have a tacker use some but he was young and well built. 2.4m is doable though.

I have used similar for a conversion when NHBC were prohibitive. I did not have any issues with the resales x 6. No real chance that anyone could successfully claim against it, but most lenders accept a professional consultants certificate.

And the dog in Downton but I still would not name a bath after it!

As a rule of thumb, a 1m3 soakaway does about 60m2 area, so take you area, divide by 60 and that should give a suitable soakaway size in m3.

Maybe just get a couple of packs to keep you going. I think more places will open in the next few weeks. Might be worth a call and haggle?

Look at compatible sold values. Ask a couple of estate agents. Look at values per square metre in the area. 2 easiest ways to mess up are overestimate the GDV and underestimate full costs.

Is it part of their Taliban range? Who thinks up these names?

Hi @Spainy86 and welcome I do this sort of thing for a living. The most important factors are (1) the achievable sale price (GDV) and (2) the costs (land, stamp, build, fees, finance). It is also important that there is a ready market for the finished units at your GDV, otherwise you will be sitting on them while all the time unable to move to the next project (as many on here have experienced). Work out the profit you need and hey presto you are a developer.