In the news

Yes you want air circulation in the loft or mould happens. Just keep the loft and living space cleanly divided.
Sorry but our different terminology confuses me sometimes. Your building practices are so different from Canadian it is amazing. Maybe just because so many of the homes on the forum are very old?

We've got hollow cavities so I'm going to look in to insulating them as well

Judging by the lathe & plaster of the ceiling below, it's a well-ventilated draughty house. vapour barriers anywhere are likely to cause more problems than they solve. Even that sarking had better be breathable.

We've got hollow cavities so I'm going to look in to insulating them as well

No pls don't you'll fuck the house it ends up allowing damp to bridge from the outside to the inside of the building....

See, this is why I need to look in to it

Cold != damp though

Damp is because moisture can't get out. The nice thing about adjusting to a freezing room is that it's no biggie to throw a window open. We do have a dehumidifier from when our place partially flooded so that can get turned on if needed. Depends on how well ventilated your place is normally I guess.

My house stays cool downstairs (although was starting to heat up after a week or so of 30°) but the upstairs gets much warmer. We appear to have 200mm insulation in the loft, would increasing it (or boarding over for storage) help much?

The walls appear to be solid (ish) Victorian with large single glazed sashes which help with heat, hinder with cold. Not sure what other options we have… maybe secondary glazing for windows we don’t use much?

This is a couple of years old but gives an idea of the state of British housing stock compared to European Tado users

https://www.tado.com/gb-en/press/uk-homes-losing-heat-up-to-three-times-faster-than-european-neighbours

Get a reliable firm to do this.

Some parts of the UK have driving rain, that is a risk.

And there is a risk of damp bridging too, the wall pointing has to be in good condition and may need waterproofing barrier transparent paint on the wall.

We had it in the rental and it seemed OK, but, worth investigating properly.

Just blowing insulation in a the wall here without informing building standards it a bit of a no-no, you can just do that in Canada?

Here in Norn Ire even roofspace/loft insulation has to be inspected and signed off.

In the attic it’s ok, the walls should be inspected and signed off unless done by a proper contractor.
There should be a vapour barrier between the drywall and the studs. Most houses also have a wrapper on the outside over the insulation. Tyvek is most common.

Impossible, Victorian houses are build to keep the heat in, don't you know?

Just blowing insulation in a the wall here without informing building standards it a bit of a no-no, you can just do that in Canada?

Houses typically aren't of (mostly) brick construction. Much more like US stuff, timber frames sitting on top of a brick / concrete basement, lots of drywall etc. When you do external wall insulation it's (I'm mostly guessing here mind) like sticking stuff in a partition wall in the UK; if you want to take the insulation out, you can, by pulling the drywall down and taking it out.

Or you just knock the house down and start again.

I'm in a valley next to a few lakes, morning mist is pretty epic here. We don't have dry air.

Cavity walls. Should they be capped in the loft space? I appear to have open cavities but from what I've read they should be closed to prevent air movement?

I'm in a valley next to a few lakes

#golfclub

I'm in a cul de sac next to a few bins :)

Or you just knock the house down and start again.

I wish the current fixation with preserving crumbling Victorian and Edwardian terraced housing would just end. People have to keep piling money into keeping outdated constructions inhabitable, for what, nostalgia’s sake?

It will keep you warm, I’m planning on doing a DIY outdoor one in the back of the flat for the time being until I have the fund to get a decent one.

Shutter might be cheaper than new windows, not as effective but make a difference.

fixation with preserving crumbling Victorian and Edwardian terraced housing

The energy performance might be shit but compared to most modern builds things like the room sizes, ceiling heights and window sizes are so much better. Add in the "it's a terrace so you have to do ~20 houses in one go or problems" and it's only the shitty mass builders that could do anything if they wanted to.

I sometimes wonder about knocking down and rebuilding my current house. It's detached so a much simpler project but still a massive amount of cash and disruption so I'm unlikely to ever do it.

People have to keep piling money into keeping outdated constructions inhabitable, for what, nostalgia’s sake

I guess it would take a fuck-ton of carbon and labour to do anything else. The 150+ year design life of a simple pile of bricks makes up for a lot of energy inefficiency.

Cos they're mostly fine, maybe a bit draughty or heat leaky or whatever but it's relatively small money to fix that. Sizes are often good, usually better than post-war buildings and they're often in nice places becaues they got built before the towns/cities got so big. If you look at a place like Japan they knock down and rebuild frequently but that's based on a very real issue that it may fall over if an earthquake hits. We don't have any threats like that here. Apart from multi million £ houses I'm yet to see anything build in the last 20 years that I'd regard as nice.

Embodied carbon. Liveability. Thermal mass. (New bricks and new concrete are expensive for us and the environment.) We don't have the skills/labour or the materials to demolish and rebuild every home over 100 years old. We barely build any new homes as it is.

External insulation: peel off outer layer of brick/stucco/vinyl siding.
Nail 1” (at least) hard foam insulation to studs
Wrap with tyvek, tape all joints and windows
Cover with vinyl siding

Rockwool is typically made to the depth of a 2x4 inch beam. On the inside of the building you strip the outside facing walls down to bare brick. Build a stud wall structure on the inside. The spacing of the beams being the width of the rock wool and the 4 inch side of the beam providing the depth. Then place rock wool between the studs floor to ceiling.
You cover that stud structure with OSB board and then attach thin sheets of plaster board on top of the OSB board.

Considering how much you've spent on the house this should be a relatively cheap jobby. The most hassle will be re-doing the window sills to go with the slightly thicker wall.
At this point you're no longer talking about tearing down Victorian houses etc. The rock wool does the job.