Mr Punter

I think it is often better to hire a decent sized (4-8 tonne) tracked excavator if it you are doing a one-off house. About £500 a week for a machine worth about £50k. You could do foundations and drains for most self builds in 2-3 weeks. If anything goes wrong the hire firm will sort it.

Part E will mostly not be relevant as this is an existing house. It has most impact for new build flats and houses where there are party walls and floors .

In my view the plan B scheme does not require freeholder consent. Without intrusive works it will be difficult for the surveyor to conclusively establish if the wall is load bearing, but is is very unlikely. I would just go ahead and get the work done.

Use Celotex instead of Rockwool. Even better if you top it off with insulated plasterboard.

Planners are often not keen to allow windows in habitable rooms at the side of a property for just the reason that it may prevent future development of the neighbouring land. I suspect that is why the room is labeled as "gym" rather than "study".

It looks like you have about 1m to the boundary. The new building will probably also be set 1m, so you have a 2m separation distance. You can install a 2m high fence on the boundary and that will prevent overlooking, providing the proposed bungalow floor level is similar to your ground floor.

I am not quite with you. Surely it will reduce the heat losses through the wall by improving the U value and therefore the room will stay warm for longer?

Yes it will help keep the heat in.

I am building 3 flats and thinking to fit gas boilers and leave it to future owners to fit heat pumps as I would not qualify for the grant but they will.

If you do the floating floor it is best to use 22mm t&g chipboard and bond the engineered floor to it. The adhesive is pricey but it feels a lot more solid.

I have not seen anything as small as those. S3i do a large range and may be able to point you in the right direction.

I have left them exposed in a conversion, but they were large beams. They need to be meaty for the char rates to count. https://www.designingbuildings.co.uk/wiki/Sacrificial_timber BC did not seem bothered but this was 8 years ago pre Grenfell.

Could you fit some noggins between them on the line of the supporting wall?

One for a Structural Engineer to answer I think.

They can be exposed and left unprotected subject to the section size and loading. It is possible to calculate the char rate on a timber beam. You can also apply clear coatings to increase fire resistance if required.

Make sure the exterior brick / render is in good nick as if water gets in it can travel through the insulation across the cavity and cause damp internally. Consider applying a coat of StormDry to the masonry on more exposed walls.

Remove the bead and if there is still any damp, replace with stainless steel, otherwise just new galv one.

Perhaps look at using the same heating system as in the rest of the house, unless you want to separate it off. Get the whole basement dry and insulated. For ventilation you could just have trickle vents in the windows or a background fan.

The window head looks damp. Is there a trickle vent at the top of the window? If not, install one as you need proper ventilation. Line the window reveal (top and sides) with insulated plasterboard. Look outside and make sure that no water can get into the wall.

It is good to have the glazing near to the centre of the insulation but not fatal if you don't. It is becoming more common to have airtight tape internally, adhered to the window frame and back to the structure. You may also have some insulation on the internal reveals to stop cold bridging through the timber. Foam around the frame. Compriband is good but silicone will also work. The metal flashings and dpc at the heads is good.

That is so handy if you have pipe runs behind appliances.

Shevek over on Green Building Forum did an EnerPHit on a Victorian Terrace. Might be worth looking up if you can make the search thing work.

Most of the systems are very good if they are properly specified and installed. SIG roofing have a lot of information but are a supplier so have a vested interest.

If you keep the lime tree, don't park anywhere near them as the sap is hard to remove.

If the planners don't like your proposal they will often contact you and suggest an amendment to the plans so you could move the garage if it was an issue. It may be worth showing what you could build under PD, as this could include additional outbuildings and an extra storey. In reality you are doing the right thing by demolishing as you get a much better product. Don't make the Council Tax a major factor in your decision making. Seems odd that it can't be removed from the register for 8 months if you don't demolish before February. I would question that.