jack

Not sure I follow. What sort of heat pump do you have in mind? Air source? Air to air (ie, air conditioner)? One inside an MVHR unit? Or one of those ecocent type units that use the internal great from the house to generate hot water?

Yup. I assume it works!

If you mean an ASHP, that isn't how they work. The air in the garage would very quickly turn freezing cold if you did that. You want a constant supply of environmental air, from which you absorb heat (and that will happen even if the air temp is very cold). Not only do you want the exchanger outside, you want it in a clear space to that you get good airflow around the unit.

Screws also often have sharp junctions where the thread meets the core. This is a focal point for shear stresses (especially if the thread goes all the way to the head), which may be another reason why screws aren't appropriate in shear applications.

Lovely looking house - moving in is such a great feeling!

Hi Pieter, and welcome. In general, there'll be a minimum fluid volume that the ASHP needs. In my case (Panasonic), the minimum is something like 70L, which is more than covered by the UFH loops (edited to add: nearly 800m of loops, I believe) and long flow and return pipework. You'd need to check for your model - my guess is that you may need a buffer tank if you only have 4 loops and a high capacity ASHP (mine's only 5kW).

+1 for the HHGTTG reference.

Bully for you making the difficult decision to delay in order to get it right.

I'm far from an expert on trees, but I believe that planning permission overrules tree preservation orders. I assume it's the same in conservation areas. If your entrance is clearly marked on the granted planning application, I believe you're fine to cut down whatever trees must be cut down to achieve that. Do check this before proceeding though - it's just something I vaguely remember from several years ago when we were having tree troubles. Second, tree preservation orders only apply, oddly enough, to "trees". It's a matter of degree as to whether a hedge plant is a tree. @PeterW might know something about this...

Yup. We have two double sockets on each side of our bed: charger and lamp on both sides, plus a clock radio on my side. My wife quite fancies an electric blanket, which will bring us down to one spare each side. They go fast!

I just searched ground source heat pump installation costs. First page of results lists prices as things like £13k, £13-20k, and £12.5k. I said it couldn't be done for less than £10k and that it was more likely to exceed £15k. Not sure how anything you've said since shows that those numbers are unreasonable.

Is there any particular reason for the constant stream of aggressiveness?

The main thing that puts people off GSHP is just cost. It more or less can't be done properly for less than £10k, and for most it'll cost more like £15k+ ASHPs, in contrast, can be done for as little as £2k installed, if you're willing to do some of the work yourself.

The problem I have with all this is that the design flaw is a lack of space, but the solution seems to be reinforcing the casing in various ways. To me, that doesn't address the actual problem, even if it stops the bending.

With your "all off" switch, is it worth leaving one or two lights out of it so you can leave them on to make it look like someone's home when you're out? In our kitchen, we have a pull-out bin to the left of the sink, and the dishwasher to the right. You can dump dirty dishes above the bin if you're in a hurry. Scrape them into the bin when you're ready, rinse anything that needs rinsing (or dump in sink if it needs hand washing), and the rest keeps going in the same direction into the dishwasher. It's a very small thing, but it works surprisingly well. All our plates, cups and cutlery can be put away within a single step of the dishwasher, which also feels efficient. Think about a boiling water tap. We've had one for three years and it's just awesome. It needed a repair under warranty after two years. The three weeks we were without it were incredibly frustrating - imagine having to wait for water to heat on the cooker to quickly cook some broccoli and peas when you've forgotten to put any veg on for the umpteenth time!

It needn't add anything to the costs, depending on your ASHP. The basic controller that came with ours has a basic display of consumption and (I think) COP for both heating modes. According to the MCS guy I used, that's sufficient.

...or the inlet and outlet are too close together on the outside of the building.

With a well-insulated house, sudden drops in external temps don't make any real difference. I have no idea what the temperature is outside unless I look at the weather forecast (or, you know, actually go outside!) Also, if the warm air is let out for some reason (eg, door left open), it very quickly recovers. That's part of the joy of UFH in a well-insulated house.

Welcome to BuildHub. A few thoughts: The UK doesn't have a history of ducted air heated and/or cooling in domestic settings. The concept of using aircon to warm a space just isn't in the consciousness of the general population or domestic electricians/plumbers whose opinions would usually be sought on heating matters. Subjectively, air heating tends to be considered less pleasant than radiant heating. Heating the air The air is very dry, which some people have physical reactions to. Also, while the air in a room can be heated up quickly, in my experience the room itself still won't feel comfortable until the furniture and walls have warmed up. That's a much longer process than heating the air. I'd be wary of solutions that rely on MVHR distributing heat from one room throughout the rest of the house. It does work to an extent (we used a 1.5kW column heater in the kitchen to warm our entire house last winter), but switching on aircon heating for an hour in one room will have little impact on the temperature in the rest of the house. In my opinion, if you're going to have MVHR anyway, you're better off looking for a solution that introduces some heat into the MVHR supply. Low level heat to all rooms will work a lot better than having one room being blasted, imo. There are all sorts of options for this. If I were doing it again, I'd stick with UFH driven by an ASHP, but add a loop to allow some comfort heating of the MVHR supply air (really just enough to take the chill off the air due to the imperfect heat exchange in the MVHR unit).

Right, didn't pick that up until now. What a pain

I don't quite follow everything that's been going on, but why did you get what you wanted last time but not this? Surely that's the crux of the matter...?

We have exactly the same arrangement (except no heating in the bathrooms!) and exactly the same problem. It's always cooler in the bedrooms than it is downstairs. Presently the bedrooms are about 19 degrees, but that's with downstairs pumped up to about 22 degrees. I'd be fine with it if the bathrooms were warmer, and indeed we're in the process of retrofitting IR panels to try and address this. I quite like this bedroom temp. My wife would like it warmer, but then I'd die of heatstroke overnight. I balanced mine. The problem (I speculate) is that if you turn up the fan to get more air (and hence more heat) being distributed, you increase the losses due to lower heat exchanger efficiency, so the incoming air ends up being cooled more. Turn it down to increase heat exchanger efficiency and less air is moved around, so you still end up with cooler bedrooms! We have a very wide open staircase, and another double height area of 6m2. While the upstairs landing does warm up to an extent, the heat doesn't work its way into the bedrooms very well. The air delivered into the bedrooms is naturally cooler than the house average temperature due to the heat lost via heat exchange inefficiency. Unlike downstairs where the heat deficit is quickly made up by the UFH, upstairs, the cooled air is delivered directly into unheated bedrooms, then swept out of the bedrooms into an ensuite or the landing for extraction via the bathroom. This airflow prevents much warm air making its way into the bedrooms from the landing. As for how to solve the problem, if there's already wiring in place, one solution would be to have the electrician install power points at these positions. Assuming you have basic handyperson skills, you can then source and install your own heaters, which will be a lot cheaper than what's presently being proposed.

I'd still be unable to find a tape measure by the end of day one.

Why would they subtract the depth of the wallplate though? By definition, the joist ends have to rest on that! Ask them what they think the joists are supposed to rest on if not the wallplates. The fact that they got it right the first time around shows that they've just cocked it up. Can you kick it above the head of whoever you're talking to and get a manager involved?