jack

Yep, that's pretty much it. As said above, airtightness is important, and becomes increasingly so as the volume of the building increases. Using standard building regs insulation but working towards, say, 1 ACH will make a noticeable difference. If you can afford more insulation, do that too. Unlike insulation, which can only be improved by spending more money (twice the insulation is twice the cost), airtightness can be improved by careful planning and detailing. This needn't be expensive. I'm sure you could improve on building regs airtightness by a factor of 5 with relatively little extra cost. It might also be worth searching "decrement delay" on the forum. Choosing an insulation material with relatively high decrement delay, such as cellulose or wood fibre, may improve the perceived thermal performance of the building for a given U-value. The main improvement is reduced peaks and troughs of temperature.

Lovely looking house. Ours is about the same level of modernity but I really like the general aesthetic you've achieved outside. We have 400mm overhang on some south facing windows, and this is ideal. However, these windows are only about 500mm high (they're wide and not very tall - needed to be high up on the wall due to overlooking). What about making some of the vertical cladding (or whatever it is) into a sliding brise soleil? You can lock them in the positions illustrated above during the cooler months, and then slide them into place during the day when you want to reduce solar gain. Not sure how complicated it would be, but it would give you the general aesthetic you're after most of the year while provide excellent solar gain control when needed.

Interesting info, thanks for sharing. How much would it cost to have 120 evacuated tubes supplied and installed?

We have a new built-in Siemens bar fridge in our pantry and I'm genuinely surprised at how much noise it makes.

That's the plan. More time, more money, and no forwarding address for the kids.

Actually, I lived in a bungalow from age 6 to 18. So yes, I've ruled that out!

All those tips you gave me haven't worked. I think you're a better glider than a teacher.

The next house I do will either have a liquid screen upstairs, or use structural concrete for the upstairs floor. The impact noise in my house drives me mental.

Even some of our floors that were screwed down squeak (although far less than the ones that didn't get screws). The glue is the key, imo. I believe Egger board suggest only fixing one end of their boards with screws and using adhesive-only everywhere else.

One thing that jumps out at me is the distance between the walk-in wardrobe and the ensuite in the master bedroom. Get out of bed, walk to the wardrobe to get out some clothes, walk all the way back around the bed to the ensuite. In an ordinary bedroom this would be bad enough, but at this scale, I know it would drive me mad in short order. We have a walk-through wardrobe, which we find very effective. Along the lines of what @Ferdinand said, do some thought experiments about living in the house. Think about an entire week's worth of activities - what you do and where you go when you get up, head to breakfast, get the kids ready, have friends around and need somewhere to put the kids while the adults talk, etc, etc, etc. And then take into account whether your current layout makes all of these activities efficient. As an example, we wanted a mudroom/laundry at a side entrance where we could come in with wet dog and muddy boots. We got one, but we never really thought specifically about how we'd use the space. The result is that there's no proper space for shoe/boot storage, and it's really narrower than it needs to be to properly perform its function.

Welcome to BuildHub!

Suspect that's right, although presumably it wouldn't be difficult to crosscheck council tax records with CIL info.

Agreed. We never boost due to showers and have the system set well below BR rates, but the steam and condensation clear very quickly. I might boost for an hour if I'm cooking something smelly, but that's about it.

I seem to recall that skirting heating is relatively expensive compared to regular rads. If price is the main driver of choosing radiators over UFH, isn't that advantage eroded by using skirting rads?

I think the person-in-the-street increasingly expects to see UFH in a new build. Everyone I know who's done a significant extension, refurb, or new build has included UFH. Re: costings, I'll be interested to see how you get on. I'd happily pay more (a lot more, actually) for UFH. The heat it gives is far more even and pleasant than any radiator-heated house I've been in. We did actually heat our house for a period last year with a single 2kW electric column heater in the kitchen. Amazingly, it was fine even when it was very cold, but the temperature wasn't evenly spread through the house by any means. With a low energy house, how do you distribute heat if your heating requirements mean you can only have a very small number of radiators? If you have a lot of solar gain in any particular area, don't underestimate the advantage of UFH pipework moving heat around the slab. We have a huge south-facing slider that gets quite a bit of solar gain in the shoulder months. Without running the UFH pump, I suspect that the floor beside the slider - several square metres of our dining area - would become uncomfortably hot. There's nothing stopping you from getting someone else in to do the UFH heating pipework, or doing it yourself.

Open cell insulation won't be ideal as water vapour can get through it and condense on the ducts. I have some 180 or 160 closed cell ducting left over from my own MVHR installation if you want it. Let me know and I'll go measure it.

Bear in mind that if MBC does it and something goes wrong, they're responsible for putting it right. If someone else does the UFH in MBC's slab and something goes wrong, you potentially have a fight over who caused the problem. I'd personally consider that worth at least some sort of a premium.

My house is 289m2, 0.11 raft floor, 0.12 cellulose walls and 0.10 cellulose roof. Airtightness just below 0.6 ACH. We're in the South East. We have a 5kW ASHP and it spends most of its time in winter ticking over very slowly. It has no difficulty at all keeping the house warm and heating our hot water as required. That said, you seem to have an extraordinary amount of glazing for the size of the house. I did a rough calculation and I think we're around 50-55 M2. That's with floor to ceiling windows in several rooms (including a 5 x 2m slider and three 1 x 2m floor to ceiling windows in the kitchen alone) and large windows even on northern elevations for bathrooms. Given this amount of glazing, I'd be more concerned about overheating than how much heat you'll need to stay warm. Also, the larger the house, the greater the importance of airtightness to energy consumption. ICF generally does a good job of this, but it's worth having a clear plan to ensure you maximize airtightness during the build. Oh, and I personally can't stand air heating. It provides a very dry and unpleasant form of heat that I'd personally avoid at any cost.

You can get the active bit that generates cool mist for a few quid. You just drop it into a bowl of water, maybe in front of a fan They're much easier to clean than a proper humidifier. You can just drop the whole unit into a cup of mild disinfectant every couple of days while you clean the bowl. At that price they're disposable.

Even turning the MVHR off completely for an hour shouldn't leave the air feeling noticeably different in my opinion (and experience - I've tried it). Are you sure you haven't mentally mapped still air to stale air? Perhaps you perceive moving air as being fresh? Re: humidity, have you tried an ultrasonic humidifier? They can pump out quite a lot of moisture for relatively little energy input.

We run our MVHR at under half the building regs rate, and we never boost unless we're cooking something smelly. Condensation in the bathrooms clears really quickly. Humidity generally sits at around 50% during winter.

Wow, it's really coming along! We went white throughout, except for the TV room, which is a dark matt navy/grey, and the hall and downstairs toilet, which are a very dark matt grey-green. After a couple of years, we bit the bullet and painted the living room dark too (using a Johnsons version of Farrow and Ball's "Railings"). It looked so good that I had to physically stop my wife from continuing painting into the kitchen when she finished! I'd encourage anyone to consider at least one properly dark (not just tinted) room in their house. Do the whole room, not just a wall. It gives an amazing feel. Paint is pretty cheap compared to most other forms of decorating, and if you don't like it, you can always undo it with a bit of effort. Some ideas here.

She has voice reproduction circuitry but I'm not sure she has sound receiving capacity. Maybe with her next upgrade?

Welcome to BuildHub. It sounds like a long and frustrating experience - you have my sympathy. Perhaps the best advice is to look at the appeal decision and analyse the specific reasons for rejection. Can you modify your scheme to address each and every one of those reasons? If so, you could consider submitting a new application, and make it clear in your covering letter that the new scheme addresses the reasons in the appeal decision. Either way, at this stage your main aim would be to get the council to approve something without the need for a further appeal, so I wonder whether opening a dialogue with them might be productive. What's your relationship like with the planning department and councillors?

I've heard the 100mm rule too. Also, unless you actually have dimensions on your planning drawings shown relative to a specific datum, the only way of telling how tall a structure should be is by measuring off the drawing (even a thickish line is probably 10s of mm thick) and visually estimating relative to surrounding properties on whatever street scene was in the planning app.