PeterW

If it was me.... long swept clay bend out of the IC, and then virtually straight into the IC

I take it that you want something cost effective and not capex hungry..? If you're in the middle of nowhere then what about a pellet boiler in the garage..? Insulated pipes into the thermal stores and run it as traditional rads. RHI would be OK as long as you have the insulation sorted in the attic I expect

I'm lost... can you draw a quick picture..?? Flow is left to right..?? And the bit on the left can go..?? In relation to your foot, where does the house pipe come from..?? If that is the final connection then I'd even consider a concrete section manhole as it doesn't look that deep and if its in the driveway then it may be neater.

..?? A traditional raft is a single pour with thickened areas such as the perimeter and any strengthening beams across the slab.

This stuff is external rated and full copper https://www.amazon.co.uk/kenable-External-Outdoor-Ethernet-Network/dp/B007VCVODC

300ft is a long way for a CAT5 cable, I would put a CAT6 external cable all the way and then hard connections at either end (ie patch boxes) and then use a short cable to connect to the supplier router. Other option if you have line of sight is a Unifi DMA or similar directional antenna but I would start with the external CAT6 cable

You run the boiler for longer, it would be fine. Don't understand how an extension can have half a new floor..? What are you replacing..? If there is an old concrete floor then electric UFH is your worst choice as it is unlikely to have any insulation - option to remove it..?

Don't understand the question..? There will be a demarcation chamber somewhere between you and the main sewer - usually 2-3m from the line - and I'm guessing you are connecting the existing house side of that..?

biggest kits I have seen are about 40m but it relates to the wattage and the controller really as they max out at 16A I would be using water heated UFH if it was a new floor - electricity is expensive to run and not ideal unless its a small area

You won't notice 5mm but thats your call - I know what I would be doing.

Just ask for pump grade concrete - smaller aggregate (10mm) and more cement so you should be fine if you run it wet and have rails to tamp or screed to

Arduino is good and if you're using 1 wire sensors then you're not limited really on the inputs. Adding in an ethernet shield is plug and play, and also gives you the option for PoE if you wanted to go that way too. Dead easy to programme tbh

Either is fine but personally would have used a 215 concrete naylor on flat like the blocks and just carried through

How much are you being quoted..?? Think I paid about £6/ex-VAT Quick search found this http://www.discount-trade-supplies.com/shop/product/1925-Multi-Width-Insulated-Cavity-Closer/

OK so if you can't get fireline then go with 2 layers of 9mm board. It comes in smaller panels, easier to use and you just stagger the joints. Should make your life much easier, and you can hide all the first layer cock ups with a decent second layer..!! Skim over the lot and job done..!

So you can add a zero to any price I give you.... ? A basic garden plan will set you back £500-1000, and that's for the structure and generic planting. Want someone with a Chelsea heritage and a detailed planting scheme with nice pastel pictures, and you can seriously add a zero to that lot and double to price too.

Run 32mm to the elbow the reduce to 25 into the house, easier to drill and connect onto 22mm from there And you may find pressure is better with MDPE

Sleeve it with some cheap foam insulation but as long as its min 250mm and heading down it should be fine

Yeh just run a length of 32mm waste pipe down the hole first to stop it scratching the MDPE and put an elbow on the bottom as you won't get a neat curve with less than 350-400mm radius and you will just kink the MPDE

Any chance you can borrow or hire an SDS drill with a BFO 32mm drill bit on it..?? That would be my preference - drill at a shallow angle down the wall and see where it comes out, as you'll have to properly insulate all the pipework and it won't be pretty

Make sure you put concrete mass fill around the changes in direction and especially the last bend into the tank

Search for TeleBeam Have any of your neighbours got rear dormers..? Can do some really nice things if you go full width or peaked down to wall plate

If you are using concrete beams why are you needing a lot of ventilation ..?? It’s mainly there to stop damp getting into timber beams, you don’t have that issue ..??

What are your inner / outer skins ..? The PolyPipe closers have a 250mm plastic liner with removable foam sections to reduce down the cavity.

Standard cavity closers bonded in with low expansion foam