Mike

You still need an expansion strip around the walls + movement joints in doorways. I'd probably do the same, using clip rails to fix to pipes.

Another possibility is a quiet PC fan, though you'd need to provide it with a housing and a low voltage power supply. For example https://quietpc.co.uk/casefans

Air has a low specific heat capacity, so to warm the lounge to any great extent you'll need a fan that can move plenty of air - either a large one, or one that runs quickly - so my guess is that you'll have trouble finding one that's very quiet. As an alternative, and since the rooms area adjacent, maybe you could install a doorway between them and leave it open? Shouldn't be too difficult as it's a stud wall.

Ofwat has something to say about that : Anybody who resells water or sewerage services must charge no more than the amount they are charged by the water company. They are also allowed to charge a reasonable administration charge. The administration charge is set to cover administration costs and the maintenance of meters. It can only be charged if it is not recovered by any other arrangement, such as through the rent or mobile home pitch fee. Resellers can recover around £5 each year for those without a meter and £10 for those with a meter. The administration charge applies to each purchaser and not to each occupant... ...If your reseller charges you more than the maximum resale price, you can refuse to pay the extra amount. You can take legal action against them in the civil courts to recover any overpayment. You can also recover interest on that amount. https://www.ofwat.gov.uk/households/your-water-bill/waterresale/

Because it's cheaper to centralize the attenuators, rather than installing them per-room. And noise generated within the duct would normally be due to excess air velocity, which shouldn't happen - but you seem to have found an exception :)

No, but I've looked it up. Generic 'own brand' green anti-static / anti-bacterial duct + Wolf sealing rings + Zehnder plenums (and everything else).

Yes, that seems to be mostly the case, though it seems that there is a few mm difference in internal diameter between some. The only warning I've seen against mixing them is that the external corrugations are also a little different on some brands, so it's worth buying the sealing rings to match the duct. I didn't come across that until after I'd installed mine, which mixes them (fortunately without a apparent problem).

It's a huge problem of staggering proportions. But it doesn't mean stripping the insulation off 98% of the affected houses, as some of the headlines implied.

It could be It's probably the cheapest intervention with the biggest payback that you could make. It's not difficult either, though it does require time and lots of attention to detail. There are various threads on here that give pointers.

An ideal time to install regular MVHR instead...

It is a shocking figure, but from the extremely limited examples given in the actual report, there may(?) only be a 1% problem with the actual insulation - everything else(?) being due to a failure to consider what else needs doing, including some items that were pre-existing. But it should have been be obvious to any competent contractor that these items needed fixing! Extract from Figure 6 below; full report at https://www.nao.org.uk/reports/energy-efficiency-installations-under-the-energy-company-obligation/

Your measurements are certainly far from ideal. You mention the existing air extraction methods, but I'm wondering how air is currently drawn into the building and, in particular, whether those triple glazed windows include trickle vents that are actively used. If not, that would be cheaper than installing MVHR and may bring down CO2 levels enough, though they do have drawbacks. There have been a couple of discussions about retrofitting MVHR here - it's mentioned in some posts with @Garald as a future project, but not sure if anyone has done it. It's possible but disruptive, so easier to do during a renovation, as I have. It would certainly be an effective way of bringing the CO2 levels down. Air has a low heat capacity so isn't great for moving heat around, so it's not going to help that much at normal MVHR speeds. It can help to bring in cooler summer night air if the MVHR unit has a decent bypass fitted but, if you live somewhere when you can open the windows, that's a cheaper option. There are remedial measures that can be taken to tackle Radon and I'd recommend looking into those: https://www.ukhsa-protectionservices.org.uk/radon/information/reducelevels

For me that makes a big difference. From your first images it was believable that this may have been a single storey building that had had a second floor added. From an angle that illusion is blown - it now looks like a house with two types of decorative cladding on the front. To regain some visual cohesion I'd probably forget the wood and render the upper portion to match the side, though it's not an ideal solution.

No problem - if the intake and exhaust are on the same elevation then both will experience similar wind pressure and remain balanced.

The wood, especially after it has toned down to a light grey.

Yes, something similar, but here in France it applies* to everyone undertaking 'noisy work', not just construction and not just on a particular site. And, being France, of course everything stops for lunch *subject to local implementation & variation. The national guidelines are 09:00 to 12:00 & 13:30 to 19:30 weekdays, 09:00 to 12:00 & 15:00 to 19:00 Saturdays, 10:00 to 12:00 Sundays & public holidays.

Top advice when there's a cavity - but the brickwork under the window (and the original post) indicate that there isn't one to worry about in this case.

In addition to the above comments: The kitchen is out of proportion to the dining / living room (unless you're running an online cooking channel) Ditch the chimney, unless it's purely decorative.

It could be done, but it would need care & extra cash to preserve the existing visual appearance - don't do anything that will harm that as it would undoubtedly cut the property value. So, use brick slips to retain the look of the bricks, and mimic the timbers on the gable. The small upstairs window will the the most difficult. I'd move it forward together with the dental courses above (to maintain the visual appearance and due to the angle at which it meets the wall) and would want the insulation below it sculpting into curves to look similar to the existing. The other windows would be OK as they are. I'd temporarily remove the porch, which would then need some adaption to reinstate it - or bring the whole thing forwards by the thickness of the insulation. If all that's too much, then just leave the front and insulate the other walls, where the energy savings will be greater as they presumably have more actual wall to insulate. I rather suspect that would be my solution. BTW, worth having a chat to your neighbour to see if they're interested in doing theirs at the same time, to keep it as a matching pair.

Not a direct answer, but I'd avoid pocket doors. They tend to be harder to clean & maintain, make more noise than regular doors, don't seal as closely to the frame, and it's quasi-impossible to fix things to the partition that conceals them as there's no space for fixings / cables / pipes (unless the partition is thick). I'd only use them for a door that rarely had to be closed, using premium kit.

I agree that insulating the party wall isn't required. However, when insulating an external wall it is good practice to run the insulation for around 1m along any interesting walls if it's practical to so so, as that significantly cuts the heat loss at the junction, for minimal extra cost. For example, on a party wall, that often means running the insulation back to a chimney breast.

Similar products are common here in France. Point.P, one of the French builders merchants, stocks a dozen or so with polystyrene or expanded clay - however they mainly seem to be used for their light weight than for insulation. For insulation, it's much more likely that they'd use sprayed PU foam, as I did. It's much quicker and easier than cutting sheets, especially when nothing is flat or rectangular. Example:

One option might be to replace it with the Zehnder Comfowell CW-S 520, which has inbuilt acoustic attenuators (and can also take 10 x 75mm ducts).

Yes, if you're not mixing too much at a time.

I would add an airtight barrier across the full ceiling on the the warm side of the insulation in the position of that red line, probably using Intello (which is suitable for the task according to Pro Clima; 'traditionally' it would have been polythene sheet). The main reasons are the second and third ones that I gave for requiring a parge coat: it prevents wind blowing through any cracks in the ceiling, and stops air escaping out due to the 'stack effect' (warm moist internal air is more buoyant than the outside air, so will rise and escape through any gaps, drawing outside air in as it does so). Ideally you'd have a service cavity below the Intello and above the plasterboard. I'd also want eves ventilation trays above the insulation at the eaves, to deflect wind that would otherwise blow into the insulation - the eaves insulation is very exposed without that.