Temp

Cold can be good. Rust is a chemical reaction and goes faster at higher temperatures. If you start insulating and plasterboarding best do it to Building Regs standards. Last I looked some of the insulation companies have detail drawings for insulating/converting a single brick garage to a habitable room.

Probably worth haggling at as many local places as possible. When we built Travis Perkins offered delivery for £12 but don't know now.

If the membrane is vapour permeable I don't believe the void below it needs to be ventilated. Ventilated voids are normally 50mm. 25mm voids are just to allow the membrane to drape/sag allowing rain blown under the tiles to run down. So I believe you only need ventilation above the membrane. Tiles or slates? Hand made plain tiles tend to be twisted/irregular so there are lots of ventilation gaps, i don't think extra ventilation is required above the membrane. Slates and interlocking tiles tend to have no gaps so I think counter battens are required to lift the tile battens up and improve ventilation under them. Ventilation would be required at the ridge. This shows conventional/closed eaves but the ventilation would be similar I think. Best get Building Control to approve a sketch.

If you only want to heat it when using it as a workshop I would use either electric fan heaters or a portable gas fire. I have used one of this type in a garage. They blast you with IR heat while warming up the room. However if you are doing wood work they are pretty dangerous. Get a few shavings in there or knock it over and you could have a big fire.

Yes I think so. They appear to be concerned that an electrical fire could spread to the insulation.

I've not used them but Google found... https://plumb.build/product/47-x-225mm-9-x-2-tanalised-carcassing-timber-c24-6m/1422 £1647 Inc Vat for 55 but includes free nationwide delivery

Great site for all things paving and drainage. This is their page on French Drains. Perhaps bookmark their index https://www.pavingexpert.com/drain03#french Index https://www.pavingexpert.com/pavindex Option B would be the one on the left. The middle option is possibly better if it was all clay and you get standing water. Right hand one is for dispersing output of treatment plant.

Yeah you probably couldn't get it removed on the grounds it's not needed but it should be possible if its not enforceable due to the wording or in some cases because its impossible to comply. For example because the EA no longer issues the type of permit envisioned.

Get/do a pressure test. Pump it up to 3 bar. Leave for a few hours then repressure to 3 bar again, wait a few hours and check the pressure again. It shouldn't change during that second spell unless there is a significant change in temperature or a leak. It might change in the first spell if it's not been pumped up for awhile. You can either use the mains to pressure it or the kit is £30-40 on Amazon.

+1 You put it much better than I could.

If I've understood correctly the dormer on the rear extension will/would have windows facing sideways? In that case to be permitted development the glass would have to be obscure glass. The property hasn't been converted to flats has it? Flats don't have permitted development rights.

Conventional central heating heats the air in a room so you feel warm by conduction. IR heaters work by heating you directly. In theory the latter allows you to have lower air temperatures with the same comfort level. I've only used IR heaters in a garage open to the elements. The side of me facing the heater was fine, the rest of me was cold. We have wet UFH and it doesn't allow us to have our stats set any lower. So I question if UFH has this "direct heating" effect.

I would suggest checking the clauses are enforceable. https://www.fladgate.com/insights/restrictive-covenants-do-they-mean-i-cant-redevelop-my-property If your Package Treatment Plant meets certain rules I don't think a permit from the EA is needed. This might mean a permit cannot be obtained because the EA doesn't issue them to plants that comply. That in turn might make the 7th clause unenforceable on the grounds that a permit can't be obtained. I think more investigation required. Google says unenforceable covenants can be removed via the "Upper Tribunal (Lands Chamber)" but this might take time and money.

Might be possible to adjust the hinges of the doors either side to reduce the gap a bit.

My first reaction was.. has the oak been sealed/waxed? It almost looks like water damage from wet feet/shoes.

Can we have an outside photo? And possibly one with it open. It looks like standing water is being blown under.

During construction our council wrote to tell me they expected us to be complete by date. We wrote back to say it wouldn't be complete until new date a few months later and they accepted it. Bear in mind they sometimes use sat images to look for signs of occupation. One option might be to claim only site workers were living on site from date but it only became habitable on later date. Let them have a small win and hopefully the won't backdate it further.

I suppose in theory if you raise any area by more than 30cm they might call it a "raised platform" but I think its unlikely to be a problem unless you create something very ugly or large in area.

+1 Most services are standard rated and not reclaimable. If there is any material supply on the same invoice (eg supply and fit) then the whole lot should be zero rated to you. It's always best to get a quote changed before you accept it. Much harder after the work has been done. Tip: If you don't have planing permission yet, include a landscaping plan in the drawing package and you can reclaim VAT on any trees on it (but not plants?).

We've had our level entrance some 15 years and would build one again even if it wasn't part of the regs. Much easier getting appliances into the house or anything on a sack trolly. Just this week our son broke an ankle playing rugby and is on crutches. So much easier for him going in and out to the car.

Some self builders are partly filling studwork with PIR leaving a void for services. Seems insulation contractors don't think its wise to use PIR around ducts... https://www.constructionenquirer.com/2022/11/02/contractors-call-for-ban-on-indoor-use-of-pir-board/

Nope. Its a 12mm (or 15mm) step. This or similar sketches can be found on the web.

I'd be surprised if any university that had built a house for the purposes of testing energy consumption and insulation etc hadn't done a pressure test on it at some point already.

You might have to change that door sill to meet Approved Document M. Get that sorted first. There is some risk of rain blowing onto the patio area. No problem with it being level with the door but where it meets the wall of the house you could put a 6" wide channel full of decorative stone to provide drainage and reduce splashing above the DPC. Something like this..

In our experience the drain doesn't need to be really big if the whole thing is raised up..