PeterW

Don’t do it ..!! ASHP supplier is talking rubbish ..!! A diverter can transfer seconds worth of excess power to a resistance heater (ie an immersion) that reacts instantly. Try that with an ASHP and it will not even power up the fan and compressor before the available power is used.

Pitch and headlap relate to the slates. Depending on the size of the slates, the pitch of the roof determines the headlap or overlap and the sizing of the slates too if they are diminishing size etc.

Noooo... Indirect has a single coil that rhe ASHP is connected to. It hydraulically separates the UFH from the ASHP so you don’t need antifreeze in the UFH etc. Direct is basically a 60-90 litre cylinder with lots of connections - fluid from the ASHP flows through anything connected, including into the UFH loops.

Use them all the time now and so quick to use. Surprised they haven’t brought out a Quinetic ceiling rose yet.

I use MKMs version of Vent3 which is about £60/roll but is just rebadged Cromar.

1m gets used for hips and valleys sometimes to stop having to cut down rolls. Tend to use 1.5m on big roof sections.

Wonder if those heras bases holding the water up will become a permanent installation..?? 🤣

Buffer doesn’t need a low loss header - one or the other. Depending on the buffer you use (Direct/Indirect) then all you do is a feed from the buffer to each manifold blending and pump set which can either be tee’d or each manifold can have its own feed off the buffer. Returns can be combined to the bottom of the buffer. Stat on the buffer in series with the time switch controls the ASHP CfH signal. Some will say you need a zone valve to each manifold but given the mixing valves on a manifold allow very little flow unless they are calling for heat then I don’t bother. What is heating the DHW/UVC..?

Water with a bit of washing up liquid !

Even the pro’s when paid to do a decent job get it wrong ... this is in a very nice hotel, and is one of only two loft suites in the hotel so £300+ per night.. tiling is pretty good, then you see this behind the freestanding bath in the bedroom ..!!

A slightly different way but all mine are done like this now.

Why PIR..?? Just pack the cavity with fibre insulation as that’s better for sound reduction and easier to put around cables and pipes that will be running through the space. Have to say, the routed boards seem (an expensive) solution looking for a problem. If you have standard width rooms at say 3.5m, a 45 pitch will give you a ceiling height of over 5m at the apex, you won’t notice if the outer wall is 2m or 1.95m ..!

2m at the eaves is more than adequate so losing 20mm is nothing. You also need to consider that for an easy joist type system, the boards are glued to the joists to make the whole structure stronger. Pre-routed boards wouldn’t do that as well, and would also fill full of crap and rubbish such as plaster if the pipes were not immediately laid and then you would need a covering - either temporary or permanent - before you could continue. I would be using an overlay system and also getting insulation under the main boards for both sound and heat insulation - you want the heat upward ..! Have you discounted using one of the spreader plate systems under a standard floor..?

So reading that, you have to include Solar PV anyway - is it in the design ..? ASHP isn’t an issue - get the UFH and rads designed right and the insulation levels sorted and it should be fine. Also worth revisiting the windows - those don’t look good values for the overall openings but bank the savings.! Also, has he done the initial DER on the bare minimum values to get a pass ..?

Is the store part of the existing property boundary ..?? i.e. has it been used as ancillary to the current dwelling as a store..? If so, it is deemed to be part of the existing dwelling house and any conversion would be at 20% VAT not 5% VAT. The lower rate only applies for conversion from one building type to another (office to residential etc Also, it’s highly unlikely you will get PP for the second 1 bed dwelling on it’s own as the council won’t see it as such. You won’t get any refund under self build VAT as you won’t qualify, and your mortgage funder is unlikely to fund the second build as it would be commercial. Unless you must keep the store, I would bulldoze the lot and start again.