Temp

This. The spur can be wired into the back of the socket giving both sockets free.

It can be worth connecting your MVHR into an energy monitor plug. As the filter blocks up the current consumption increases, or at least it does on mine. Our filters are quite a coarse foam similar to that used to filter aquariums. I can wash them out with a garden hose or in a bucket of hot water.

If I've understood what you want I would replace the boundary wall at the courtyard with a new wall inline with their parapet wall. Yes I know it means sacrificing 2" or so but sometimes going for the neat and tidy option is best. Especially where waterproofing is involved. This approach would mean all the rafters would be same length an angle. No joggle/step in the gutter. Then I would copy their roof but mirrored over and longer to fill in the courtyard area. Their lead work looks a bit untidy at the ends (?) but the joints on the parapet wall looks neatly done to my eye. Lead flashing and secret gutters are tricky to get right and some builders just can't seem to do it. I would suggest getting a detail drawing done for this area, possibly by a dedicated lead worker? Make sure the builder follows his drawing and has him come back to do the lead work.

The wiring centre controls the manifold pump. The wiring centre also controls the ashp unless you also have a thermal store.

For a single zone set up you have one stat connected to all of the actuators on the UFH manifold. If some rooms overheat you can potentially adjust the flow to those rooms (balancing). You could also consider running the wires to allow extra room stats to be added later. 1mm^2 or 1.5mm^2 wire is normally fine for the stats. There should be instructions with the wiring centre but note some are designed for 12V stats and others 230V. Some fancy systems can also transmit data to/from the stat and might need an extra core in the wire or use CAT 7 cable instead. If in a rush I would install 3 core and earth mains cable as that can cope with most basic stats/programmable.

May have to get the court to amend any order.

Might be necessary for Building Regs Part E sound transmission?

Unless your deeds say it must be a wall I believe you could replace it with a fence.

Needs a proper survey.

I dont see why they wouldn't install a supply to your plot. You're going to need a temporary supply anyway.

Welcome to the forum and good luck with the planning application.

I think you would have to write to the company, give them opportunity to rectify within say 14 days or else you will consider them in breach of contract. After those 14 days write again to tell them they are in breach of contract and you will use the retainer to fund the repairs. Send letters recorded delivery to the registered office and the reciever. Keep copies. You probably should get several quotes for the repairs to show they are "reasonable" and don't include anything not a repair in case they are ever questioned. I'm not a lawyer.

We have burst watermains about once a year in our area. Think they are asbestos cement and it cracks when the clay moves.

I wonder if you could find a private BCO who would give an opinion on the suitability of the slab (for a hours fee probably).

Think I'm hot on the trail of the problem. Found installation instructions for both mixers and they BOTH have non-return valves built in. So mighty relief as unlikely I will have to bash holes in walls after all. The flows are balanced, all mains pressure and near identical pipe runs. However the hot goes through a heat exchanger on a thermal store. Water from the store is circulated through through the other side of the heat exchanger by a pump triggered by a flow sensor on the cold pipe. Eg open a hot tap and the cold flow starts the heat exchanger pump. Annoyingly the issue seems to have gone very intermittent. I was able to trigger the fault once and check the flow sensor was calling for heat (it was) but it started working again before I could check if the heat exchanger pump was running. I'm leaning towards the pump or the supply to it being the cause but need it to fail more repeatedly to fault find it.

I've just discovered one of my shower mixers is supplied with non-return valves built in so perhaps I'm barking up wrong tree. I'm going to have to do some more fault finding.

Just a heads up... Recently finished a second bathroom in our house and turned on the isolation valves for the shower. At first it appeared to work well but after a few mins the water ran cold. Its done that several times and it's not an issue with the boiler and tank running out of capacity. I need to confirm this as the cause but I have a horrible feeling our plumber didn't install any one way valves. So at an unused shower it looks like water is flowing from the cold feed through the shower mixer and back to down the hot pipe, then to the shower in use. If that turns out to be the problem it's going to be "interesting" getting access to the pipes to install four one way valves as both rooms have stone tiles. I also think all four pipes are 22mm copper and run super close together in a stud wall so getting 22mm compression fittings in might prove a nightmare. Oh joy of joys.

If measuring the flow out of a pipe without the funnel take several velocity readings over the area of the pipe outlet and average them to give an average velocity. Then use the cross sectional area of the pipe in the calculation instead of the area of the anemometer. This is a little inaccurate because of the way you calculate the average velicity should be area weighted. There is more slow speed air around the edge than high speed air in the middle of the duct.

m/s is a linear velocity. L/s is a volume flow rate. To convert between the two you first need to know the cross sectional area in m^2 (aka sqm) where you are measuring the velocity. In your case you are funnelling all of the air through the anemometer so that's the area you need. The radius is 3.25 cm = 3.25 * 10^-2m. So the area = Pi * (3.25 * 10^-2)^2 = 3.32 * 10^-3 m^2 The flow rate in cubic meters per second is then the velocity (in m/s) * the area (in m^2) So let's say the velocity was 1 m/s... The flow rate in cubic meters per second would be.. 1 * 3.32 * 10^-3 = 3.32 * 10^-3 m^3/s To convert that to L/s multiply by 1000 because 1m^3 = 1000L So in your case with the funnel .. 1m/s = 3.32 L/s

I just had a look at the lot20 stuff because I might also need to replace some in a flat. Talk about confusing. They appear to consider electric heaters about 33% efficient (perhaps because ASHP have a COP of 3?) and then allow you extra % credits for having fancy controls like open window detectors. I wonder what jobs worth thought this scheme up.

Yeah Openreach told me something similar, I would have to have an overhead line etc etc. We ran the right wire to the bottom of the pole underground when we did the electric and the engineers that (eventually) came to install our line were happy to use it. Local companies that sell duct usually know what the DNO want. Eg must be smooth bore solid duct not twin wall. 3/8" polypropylene draw rope.

Not when we built. Most were ok with being paid in stages in arrears with 5% retained for snagging. Our builder did ask if I could help with cash flow once and I agreed to buy the windows myself.

Just make sure the sand can't be washed out at the edges?

It is when on load but I was thinking more about the losses running the inverter in a standby mode waiting for a load.

Yes If its not moved in 10 years should be fine.