Owning your own home

Trying to airtight seal the envelope of an older house is proving interesting.

Can imagine. Doesn't strike me as worth it for any building, let alone Victorian tbh, but then I guess you are using the MVHR to put some ventilation back?

Yep, continuous background ventilation with 98% heat retained. No need to punch holes in the external walls (100mm PIR).

We'll be well beyond the performance of an average new build at around £1k materials and many days of faffing! Should pay for itself in ~2 years.

a very noble goal, i both do and don't envy you..! photos always welcome too :)

I’m wondering if we will end up with something like this in our flat once gas is made prohibitively expensive/banned. there is a central flue running up the middle of the building and a vent from the cupboard around it into each room from the original warm air gas boiler (removed) so there is space/ducting and a source of air. obviously you need everyone in the building to stop pumping boiler exhaust into the flue...

what additional heat source are you planning?

Will you be able to get your windows to meet the requirements?

No need to punch holes in the external walls (100mm PIR)

External insulation is something I'm interested in (Edwardian place, single skin). Is that the route you've gone down?

Here's the lounge process, but we've had to do 4 external walls so far.

Bought a Zehnder ComfoAir 350 for £500 (deal). We have a radial ducting plan which involves lowering a (tall) corridor ceiling by 20cm to move against the joist direction... fingers crossed.

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Unfortunately not as we're in a conservation area, external would've been higher performing and easier.

We've got an old draughty victorian terrace but everywhere seems to be around 45% with the exception of the dining room at the back which is in the low 50's. I thought it would be higher than that so I'm pleasantly surprised. We have a heat pump dryer so never dry clothes in the house and with the exception of when we have guests staying only shower/bath in the bathroom in the loft conversion which has much better insulation/ventilation than the rest of the house so maybe that's why the humidity isn't higher?

Yeah. Surface area on that is small enough as it is, and you are still left with the cold bridge from the external through in to the dividing wall on the left. External FTW I think.

I'm still waiting on a decent government backed scheme before we remove the gas line.

We could use an air source heat pump as the background heating demands will be much lower, but I'm also not against using PV for hot water and/or heating with overnight electricity top-up (if that ever comes back).

We'll have a sealed 'eco' wood burner in the lounge (drawing air from under the suspended floor) for some interim heat and a 'single warmer room' option if we decide to keep the background heating low.

good point, secondary glazing (6mm low-E, 100mm gap) and 60mm of Kingspan K118 insulated dry lining over brick/block non insulated cavity with a small bit of solid wall.

basically doing what we can until all the technology/laws/permissions/costs become clearer.

Excellent work. We've done almost the same in a 1880's tenement flat, top floor so put 100mm pir + moisture barrier across each ceiling as we go (bedroom, hallway and bathroom so far, kitchen + front room will be next years project), front room and bedroom and back of bathroom walls done in 50 or 65mm PIR depending on usage and barrier. Yes makes your rooms a bit smaller but the bedroom + bathroom the difference is insane. Can heat the bedroom on a <1kw wall heater to a furnace easily and will maintain temp over night nicely. Bathroom is in middle of building, but has a cold wall into the common stairwell and another wall thats into the next building, but roof line is only a few metre above and does a pretty good job of conducting heat away. Bathroom is now heated by around 400w of heated floor + waste heat from a current generation unvented cylinder. Previously it was like walking into a smelly wet cave.

External insulation is likely easier/costs less as you don't have to almost entirely strip interior of building out and has bigger gains, gets around a lot of cold bridge issues.

Making an older stone building entirely air tight is difficult and then you get a whole host of other issues, moisture instead of getting driven out of the stone starts making its way into the building etc.

I was called by Beko last night, cheerily telling me that they'd ordered the part and had an arrival date of 5th December - would I like to book an engineer timeslot? I obviously lost it at them, and am now in possession of an 'uplift' code that AO will use to replace the machine.

AO have now informed me that that model is now discontinued, but at least the end is in sight! thanks all for the help on here!

Non-party dividing walls are typically timber in older buildings which helps with the cold bridging between rooms a little. I did model some return insulation into the room too, but decided against it.

Assuming your neighbours heat their homes to the same temperature, the main benefit of improving an old terraced property is the proportion of volume to exterior surface area... we're around 350 cubic meters to 60 square meters of exterior wall.

By contrast, a 9m x 9m detached bungalow (200 cubic meters) with 80 square meters of exterior wall is going to lead to reduced gains for increased cost.

External insulation is something I'm interested in (Edwardian place, single skin). Is that the route you've gone down?

Unfortunately not as we're in a conservation area, external would've been higher performing and easier.

That'd be rendering the outside, or is there some alternative?
Have seen a few options with brick slip faced external insulation, but not sure if it'd just look a bit shit on a Victorian terrace/semi.

First step is to check your roof overhang as some older properties aren't generous enough.

In theory you can have ANY exterior finish, I'd avoid trying to match what exists already.

We're getting quotes in for external insulation at the moment (Victorian end of terrace, currently acrylic render, couldn't look much worse), and are being told that the roof will need extending. Which will mean a new roof entirely, as it's on it's last legs as it is.

Couple of options here for not extending the roof and going with a hidden gutter. Although there's always a bit of a maintenance risk with that (not so obvious or easy to fix if gutter is blocked). https://retrofit.support/category/EWI-E/

also victorian end of terrace here

Would the plan be to remove the existing render? Is the new external insulation breathable?

Is the new external insulation breathable?

Depends which material you pick as insulation. There's synthetic and natural stuff that both claim to be breathable. Picking an installer with half a brain so that they don't fuck it up somehow will be 80% of the battle on that I reckon.

This.

Would the plan be to remove the existing render?

Yes - the acrylic render is just about the worst possible thing for a solid wall building. It fails (without fail), prevents drying out, and allows damp to penetrate.

Is the new external insulation breathable?

It isn't. However, in theory at least, it moves the dew point further out of the building, and removes any cold bridging problems.

If the render on top of it fails, it is also easier to repair & less damaging to the substrate.

Again - in theory.

Ideally, I'd like to lime render properly, but that is just as expensive, harder to find trades with the actual experience. And we'd still have an insulation / cold bridging / condensation problem.

yeah lol, basically the only reason we haven't done much on the house yet is that I dont trust anyone to do anything competently and having to pay even more to reverse what's been done.

I do wonder what’s going to happen with conservation areas and listed buildings over the next 10-20 years.
There is an awful lot or rubbish housing stock in the UK that is either going to be impossible to bring up to spec or too many hoops to go through due to planning restraints.
These properties are going to be ridiculously expensive to heat and likely see a drop in demand/prices due to running costs unless restrictions are relaxed regarding windows and visible insulation.
Are people really going to remove all the period details in georgian properties and internally insulate and try to reinstate them? partners flat (being sold) is in conservation area and anything on the outside is prohibited so no heat pumps/satelite dishes etc, sash windows and no fake glazing bars allowed and most of the properties in the street are listed.
Once gas is gone the electricity bills will be stratospheric.

New flat doesn’t even have cavity wall insulation as you need to get everyone to agree to it and do the whole building, supposedly the cavity sits outside the edge of the concrete slab and runs the whole height of the building so needs to be filled top to bottom.
Architecturally of note so not allowed to alter the exterior so no heat pumps on external walls and how do you service one on the 8th floor without paying a fortune to access?

I’m all for energy efficiency but i see a lot of ups and downs before we are all sitting in toasty period homes and not paying insane fuel bills.