Conor

From the collective experience and wisdom here, the consensus is stick to standard, proven methods of construction. You have to take account of the what most builders and trades are used to working with. Start doing something unusual, and somebody down the line will cock something up.

What are you retaining and how high?

Evolution is great,.I've the 255mm one. For second fit stuff, get a 80tooth TCT blade instead. The multi purpose one does not cut smooth at all. But it does cuts like this....

Ground mounted?

You set yourself as both client, principle designer and possibly contractor as well. However, if you are getting a builder in to organise more than a single piece of work, they should be the principle contractor at the time they are working. We did it that way, the off guy was principle contractor until he left, then I assumed the responsibility as I was directly contracting people in. (CDM 2015, Northern Ireland)

Good luck. Definitely highly unusual to fit a door like this. It's not a terribly difficult fix either.

Mild soap, plenty of scrubbing, and water is all you need to clean a patio. Soap will breakdown well before it gets near your plants. Acid based cleaners should be avoided, but these will breakdown quickly as well. Bleach and commercial cleaning solutions are your worst enemy here.

Normal door is fine. We've a timber and perspex door which would last about 10seconds in a fire. If you intend on never closing the door... Is there an option to is tall ot as pocket slider? You'll never know it's there but you'll still be compliant. Basically what we have. Only close it when I'm cooking something funky.

Ask the SE if a ~100mm thick padstone would suffice. Put it in as a full block width. Save a lot of faff.

I just Invite a few friends round for dinner. Few adults and a load of kids running around the house easily adds a kilowatt or so.

A few basic things in reality Vs model. Your heat load is worst case, constant over 24hrs. If it's 5kW, and you've a 5kW heatpump, it won't be enough. Purely because the sCOP (and other inefficiencies, needing to heat water etc) will be less than the label, and you won't be putting enough energy in to the building. You'll need more like 6 or 7. You'll likely run the building as a single zone (or one per floor, like we do) adjusting individual room temps be tweaking flow temps. You might add a buffer. Your mvhr will modulate down when really cold, to protect against low humidity. You probably won't want to run your heating 24x7 (which these models assume). We run ours for 7 hours on economy 7. These things are hard to model. And the reality is you have to just go with close enough, and stop worrying about decimal places. Our peak heat load is something like 5.6kW. but we've no curtains on the big glazed areas, so its probably higher. I went for a 9kW heat pump that modulates down to 2.5kW. it's perfect. When it's really cold, I just adjust the timer so it's on 20 hrs a day, rather than 7. Room stat and weather comp takes care of the rest. If you end up with too big a heatpump, you can easily compensate with behavioural changes. E.g, fewer zones, running for shorter periods of time, buffer tank, and still hit good performance efficiencies. If you end up with an undersized heatpump, there is literally nothing you can do to compensate in those challenging periods. Only option is supplemental heating. Defeating the purpose of an efficient heating system. You need a 7kW heatpump.

Yes same here, glass is overrated. Esp in July when it's 30c outside, or January when it's -10c.

How on earth did they remove the old posts? Just pull them out of the ground?! We're they not concreted in?

Nope, no requirement under BC regs for this. Old school thinking from your plumber. Save yourself a bit of money, hassle, and a compromised building fabric and go with the AAV. Read up the building control regs relevant section (a Google search should get you this) and you'll see that it specifies adequate means of air admittance. I'm in NI but our regs are basically a copy and paste of the English ones. Scotland is different tho

The mvhr doesn't make that much of an impact. And it's only the overall rate they matters. Airtightness is a bigger factor. We designed for 3ACH, and achieved 1.5. don't be confusing building airtightness with mvhr flow rates. You'll be wanting a 7kW ashp.

Install an internal air admittance valve instead. We've three stacks in our house, each one with an AAV. No need for an externally vented stack.

If it's a full gut job, plumbing, wiring, insulation, windows etc, start with £1000/m², then add on kitchens, furnishings etc.

Do you mean you want to remove the door from the kitchen - living area and the hall? If this is the case, all of the other habitable rooms need their own compliant access to the outside (not the hallway) as you effectively turn the hall into a kitchen.

It'll be fine. Especially if it's just aluminium gates, probably only going to weigh about 80+120kg for the big one. I'm about to build a 4m, 200kg wooden gate to hang off the same size pier! My hinge hooks are 300mm deep threaded rods. I was worried about a standard plate pulling a brick out, so going OTT.

Nope. Will be fake. Some have both things like this, and they aren't terrible.

What sort of I underfloor heating and how will it be heated? Don't listen to the builders re insulation, they are used to doing things to the minimum standard. Saying that... 300mm EPS is probably the best option here. You won't need SLC if the floor is done right.

Build a smaller house. 315m2 gross (250m2 habitable space) is too big for a family of 4. I'm currently working from home in one of our basement rooms.... 50m2 with a desk and some shelves 🙄

I'm guessing your walls are solid 9" brick, no cavity? Or is there one? In a cavity wall situation: You'd normally install a door or window so it sits to the inside of the outer leaf (like the original here). Some issues with what has been done, water will get in past the frame as it's sitting on the render, rather than behind it. Hope there is plenty of foam/sealant etc in there. Second, you are guaranteed to get condensation all round the inner reveal, as it's a direct path to the outside. Finally, as it's sitting out further, it'll be more exposed to wind driven weather.

How were the doors installed? Do you have a pic from the outside? trying to figure out why, what was once on the outside, is now on the inside?

Take out all the timber and replace with the same block that's at the bottom.