PeterW

... or you need both a flow and return......

Underpants on the outside.... Head north to the land of Iron Bru and McEwans Export ....

What is the thermostatic valve set to..?? Top left above the pump.

First question should always be - do I need to use B&B or can I use a ground bearing slab. The issue you may face is not having the DPC high enough above ground level to satisfy the BCO. Do you have a largely sloping site..?

Got a photo of the blending valve..?? And the manifold..? Blending valve could be on back to front

That is a GSHP.... so it sounds like they replace the GSHP coils with their fancy bits of steel in the water. Could do the same with a series of coils in the canal bottom if you could get them to agree for about £500...!

130 or 150 degrees from memory.

And then what on top..?? How are they detailing around the rooflights..??

So that’s a wall U-Value of 0.24. What’s the DER/TER from the SAP calcs..?? I would be looking to add a minimum of 25mm if not 50mm of insulation to all the internal walls after a parge coat or at least pointing up all the gaps.

Where in the UK are you @DaveH as I can’t see how 50mm hits BRegs unless it’s a conversion or extension ..??

Push the switch all the way to the right ...

Spiral staircase ..?? Wooden treads..? Would look very nice ..!

Not at all..! You can buy with PP, then apply for Non Material Amendments to make minor changes, or go with a brand new PP to get what you want. As long as you commence the original PP before its expiry you can lock it in and then apply for something else so you always have a fall back. Also worth bearing in mind that within reason you can make any internal changes you want to a set of PP designs without having to get permission. The only difference is when something like a roof light that has no visibility from it (for example a double height room) becomes part of a room where it could potentially overlook a neighbouring property.

Welcome ! Sounds like a challenge - have you considered using steel with oak treads..? Would be more stable and if the oak weathers over time it would be easily replaced.

Cat5/6 and Sat can go in the same duct or bundle and won’t interfere with each other.

8x8 will be too small for anything more than 2 children - how are you planning on supervising this area ..?? If you put an adult into the area too, then you’ll need a lot more floor space ..!

Just run ASHP and top up the DHW using immersion’s on E7. It’s a 300 litre UVC an 165sqm 3 bed 2 bath property with a 9kw ASHP

The question becomes whether using a Sunamp direct on E7 (as per @TerryE) is as efficient as the cost of the additional components needed to use the ASHP to provide the heat to it. ASHP at 35c is pretty much perfect to provide the heat required for a slab - isolating the two also means you’re not having to run it through the summer to heat the DHW and can leave in cooling mode if needed for the floor.

I use the CPC ProElec ones and they work really well and work out about £1 each. You can chose the warmness off the light too - 2700k being warm white, 6000k being nearly a blue white.

I can get 4+ from ASHP - don’t believe the hype of the other competing suppliers..! Also look at the TCV - GSHP need a 5-7 yearly antifreeze change that can be pretty eye watering in cost.

CoP of 4 is aspirational and usually based on perfect temperatures such as 7/35 for ASHP. Dropping the source temp and increasing the output temp seriously damages the CoP and you can end up at a CoP of 1 when the immersion’s are providing heat.

So surprise surprise, the RHI equals the costs ..!! Walk away ...

Right .... so brand new, I would bin the Oil Boiler and go all electric. Sunamps off E7 electric for the DHW and ASHP into the floor as the heating.

Quote is based on worst case Building Regs - so basically RHI pays you to not invest in anything more than the bare minimum for insulation standards

Can't tell, and if it is then the top immersion is on permanently from the switch, and the bottom immersion isn't on at all as its time switch isolator is off....