jack

The main reason people have built the way they have in the past is responsiveness. If you don't have much insulation, you lose a lot of heat, so you can treat a thin screed almost like radiators, in that it will heat up fast, but also cool down fast. Once you have a lot of insulation, like those of us with passive slabs, the slab becomes more like a storage heater. For that reason, having it thicker works better, plus why pay to lay two loads of concrete when one will do? We did actually effectively end up with a screed on our slab, but that's because we went for polished concrete (late decision). There's no insulation between the slab and the screed though. There'd be nothing stopping you from topping a slab with a separate screed, but why would you if you plan to cover with flooring anyway? If you have any bits of concrete spills left sticking up, you can just grind them flat with a scrabbler or a floor grinder. Lot cheaper than a complete screed!

Utterly terrifying. I swore out loud when I saw that picture (having thought "bloody hell, I wouldn't want to be working in that gap" when I saw the previous pics). "The groundworkers had decided that they wouldn't get in that part of the excavation (between the concrete walls and the bank) in case of further cave-ins, so myself and a couple of mates sorted out the drainage channel." Sounds like you had sensible groundworkers. Please, for the sake of the people who love you, when a tradesperson tells you something looks dangerous, listen!

If you want to talk to an engineer who knows about raft foundations, MBC used (and may still use) Hilliard Tanner. Website is http://www.tsd.ie/ Hilliard REALLY knows this stuff inside and out, and I found him very approachable when we had a few questions during our build.

Thought it might have been!

Just for clarity, MOT type 1 includes fines, and isn't free-draining. I think the stuff specified by MBC's engineer is something like "18-35mm, no fines". We used recycled railway ballast. If you choose to do this, make sure you're getting stuff that's been steam-cleaned. Ours was filthy with god knows what, but it was delivered and laid while I was at work so there was nothing I could do about it.

I have a spare one that I didn't get around to returning in time. It swivels (a lot!) but only has a small amount of tilt (which I think is typical): You're welcome to it - PM me if of interest.

I don't know about that. There are various open source solutions that continue to be developed, as well as proprietary solutions like Loxone which (for the moment) don't charge for their app. The app is updated reasonably frequently (I should say that I only very rarely use the app - a couple of times a month at most). I think the bigger danger is a company going out of business and leaving you with unsupported hardware. That said, as long as you stick to non-proprietary input and output hardware (eg, retractive switches for inputs, relays and/or DMX for outputs), you're reasonably future-proof. I could replace my Loxone system with another solution with little change to any of the wiring, although it would be a pig of a job just based on complexity.

I suspect that to see a real benefit will take at least several months and probably a year or more of proper training. Learning how to lift things would be faster, and certainly worth doing imo. That said, I firmly believe that everyone should be lifting heavy things and doing high intensity interval training, no matter what their age or current fitness level.

Welcome aboard. I remember being at this point in the journey, many long, sleepless nights ago!

Welcome!

That's very neatly done cladding - looking good!

Not for me, no, but I hear about it a fair bit from everyone else in the house! I think it's just dark and miserable, and people are looking for excuses not to get out of bed. I suggested turning the MVHR rate down in hot weather, and the same applies when it's very cold. A slower fan speed will reduce the rate at which the energy is transferred, which naturally becomes more critical as the temperature outside diverges further from the desired temperature inside.

I knocked up a spreadsheet in summer when I was trying to understand how cooling downstairs affected the upstairs temps. You basically fill in the orange boxes with starting state, and see what the impact is on other temperatures. Assuming 80% efficiency, 6 degrees outside, 18 degrees upstairs and 22 degrees downstairs, you can see that the temp of the supply air is actually only 17.2 degrees, so : Bumping efficiency helps - at 90%, the supply temp is 18.6 degrees. Lots of assumptions in this, but as a coarse model I've found it interesting to play with. The other thing is that towel rails and other forms of bathroom heating only heat air that's already passed through the bedrooms. While they'll have an impact on the temperature of the supply air due to the MVHR heat exchanger, half of the heat they supply will end up in the supply air to downstairs. Our bedrooms are at about 20 degrees at the moment. Great for sleeping, very slightly cooler than would be ideal for getting out of bed in the mornings.

If they aren't, then invite then over! ?

Right, I get you now. As Pete says, you'd need massive venting in the garage to allow this to happen (ie, to balance the airflow), and in any event, unless your garage has a lot of solar gain, you'd see little if any benefit.

We have a Wilo on our UFH manifold. Impressive bit of kit - utterly silent when running.

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...