[michaelt]

> Speaking about the UK [...] we have very poor quality housing stock with effectively zero insulation.

To expand upon this, consider an urban street like this: https://maps.app.goo.gl/A4HSZ2TFiJ2PyiAZ8

Beautiful houses with period features, in a great location. Big, traditional sash windows that let in loads of light. An L-shaped layout giving lots of natural light in all rooms. High ceilings. Market price about £2 million https://www.rightmove.co.uk/properties/139018139#/?channel=R... (admittedly being in London pushes prices up a lot - but the point is, these are desirable properties)

The walls are all solid brick, no cavity and no insulation. The L shaped layout means a lot of external wall area, and the big windows don't help either. High ceilings make it even harder to heat. Many of these properties are prone to damp problems if they don't get enough fresh air circulating. You can't add external insulation without covering up the period features. Obviously you can insulate the loft and install double glazing - most of them will already have done so.

It turns out nobody wants a £2000/year heating bill - but also, nobody wants to knock down and rebuild a £2M house over a £2000/year heating bill.

[a_humean]

Exactly, that housing is super desirable by UK standards - probably amoung the most desirable housing in the UK. Pretty much all of those houses will have loft conversions (you can see the loft windows in the roof) made possible in part by removing their hot water tanks.

The reality is that it is actually a bit shit. and would cost tens of thousands to retrofit. The compromises that the owners would have to make in terms of either apperance or internal area make heat pumps very unattractive.

[soco]

When you're sitting on a property valued at a couple millions, I would have thought investing tens of thousands in it would be fair game. Not pleasant, but acceptable...

[a_humean]

Well one thing is there is often a pretty big disconnect between the asset prices of these homes and the incomes of the current owners (these houses have exploded in value over the past 40 years), but setting that aside because you are basically right at least in terms of potential equity:

The main issue is to add insultation you either do exterior insulation which covers up all of the period features that make the property valuable in the first place (and could lead to complaints from neighbours) and for many terrace houses the space between the front of property and the public street is 0, or you give up interior floor space which even at this price point is actually pretty small already. Both lower the value of the home which for most British people is the primary and often only investment (UK financialisation of housing).

[michaelt]

Well, sort of.

The thing is, heat pumps aren't a particularly good deal right now.

Heat pumps generally have less heat output than a gas boiler, so it won't make your house any warmer.

Even taking government subsidies into account, the installation costs are several times higher than a gas boiler, both for the unit and often requiring new radiators and suchlike.

And typical energy prices in the UK might be 6.5p/kWh for gas, 26.0p/kWh for electricity - so even if your heat pump achieves a 3.0 CoP your running costs are still higher. In the UK, the months when you'll want the most heating are the months when domestic solar output will be at its lowest. To make savings you've got to switch to a plan where electricity costs change several times a day, such as https://octopus.energy/smart/cosy-octopus/ and not run your heating between 16:00 - 19:00. This makes a well-insulated home even more important.

And you might think you're going to save money by not paying the gas supply 'standing charge' - but gas suppliers can charge whatever they like to remove your meter. If they say it's £1500 to remove your gas meter and save you 30p/day - you're probably not going to be saving 30p/day

So it's less a case of "investing" in the house, and more a case of "investing" in good karma by helping the environment.

[nerdbert]

How much heat do you need? We've renovated a row house in the Netherlands - very similar climate - with solid foam insulation and triple glazing. Haven't gotten to installing a heating system yet. Even in the current cold period it's perfectly fine indoors with a cheap hoodie on. If I didn't know it would make the place unsaleable, I'd be tempted to move forward without any room heating system at all, only a small on-demand water heater.

[michaelt]

The estimates in that terraced house's energy performance certificate [1] are 15,992 kWh per year for heating, 2,324 kWh per year for hot water.

Of course these figures depend on how much of the day the house is occupied, how high the thermostat is set, and how cold the weather is.

[1] https://find-energy-certificate.service.gov.uk/energy-certif...

[time4tea]

(I have a heat pump)

You can get electricity at 7.5pkWh. With a battery, I get 12h of cheap electricity per day, and the rest at higher prices.

At the coldest time of the year, I'm getting an average of 20pkWh.

This is just a fraction above break even gas/electric.

The rest of the year its no contest, heat pump wins.

My energy usage for heating is down by 60% year on year

My bills are the same as they were 3 years ago.

[michaelt]

Nice. Who's your supplier and what do you have to do to get those rates? The 6.5p/kWh for gas, 26.0p/kWh for electricity figures are from my Ovo bill for this month.

[time4tea]

It's Intelligent Octopus Go.

You need a smart meter. It's electricity only.

You (and I) get £50 credit with this link: https://share.octopus.energy/happy-frog-559

[Symbiote]

> The walls are all solid brick, no cavity and no insulation.

How do you know that? Perhaps just from "Victorian", but I think it would help if estate agents were required to list some basic facts about the house — the year it was built, the basic materials for the walls and roof, the type of heating installed.

Statistics on insulation for British dwellings:

- double glazing in 87.5%

- wall insulation of some sort 49%

- loft insulation 39%

https://www.statista.com/statistics/292265/insulation-in-dwe...

[a_humean]

He knows that in the same way that all British people know that - we have lived in or know people that have lived in houses that look exactly like that house. The amount of uniformity to British housing stock can be surprising as much as their general shoddiness. Try playing UK geoguesser - every UK residential street looks the same.

There are actually very few enforced rules about house listings. The market is pretty unregulated. However that house has an epc of C which would suggest its not insulated beyond maybe roof insulation or else isn't well insulated. To get a B or above you need to have a reasonable amount of insulation that you mostly only see in new build properties.

[michaelt]

> How do you know that?

Glad you asked! For a start, as you say, it's Victorian.

For further confirmation, zoom in on the buildings with exposed red bricks and you'll see they're in a Flemish bond pattern, which only appears on solid walls. It's not new enough to have a fake Flemish bond pattern for decorative purposes.

You can also see at roof level, the party wall extends above the slates. Where it's unpainted, it's visibly two bricks thick.

If you can get into the house, you can usually tell from how thick the walls are. On houses with cavity walls, sometimes you can remove the skirting board going through an external door and look into the cavity.

You can also check externally for weep holes, the telltale signs of cavity insulation having been installed, and whether there's a damp proof course.

If you have friends in the area, they'll probably be able to tell you. If you get a survey done (which might be reasonable on a house of this age) they'll probably also be able to tell you. Often the homeowner will know too.

If you get cavity wall insulation installed, they'll drill a hole in the wall to check the cavity with a borescope and take a photo. It's a condition for getting the government grant that they confirm you don't already have cavity wall insulation.

> I think it would help if estate agents were required to list some basic facts about the house — the year it was built, the basic materials for the walls and roof, the type of heating installed.

If you check the 'energy performance certificate' (EPC) it should tell you about the insulation and heating. Of course, the qualifications to do EPCs are minimal so they don't really tell you any more than you can figure out from a house viewing. And estate agents often don't deign to produce the EPC until the house is already sold.

For this house, the EPC is https://find-energy-certificate.service.gov.uk/energy-certif... and states the walls are "Solid brick, as built, no insulation (assumed)"

The land registry's title plan will tell you when it was built for about three quid.

[Symbiote]

Thanks for the detailed explanation!

The EPC has the overview I was expecting. I had expected this to be linked from the estate agent's site, and didn't realise there was a place to search for them. (I no longer live in Britain.)

[PaulDavisThe1st]

Two small things there - not trying to take away from your main point.

(1) This is what Americans would call a "row house", and IIRC in the UK is called "terraced housing", which has the huge benefits for all but the ends of the rows that your side walls (the longest walls of the house) are insulated by ... your neighbor's house. So, although the architectural features you mention are indeed drawbacks, their impact is significantly reduced by being in a row of connected houses. It's the single-family/full-detached houses that suffer from these problems more fully.

(2) I don't see the L-shape at all.

[pm215]

For this specific case it's a bit less clear because the house has been extended significantly and so the ground floor floor plan is no longer L-shaped, but if you check the floor plan for the first floor (UK terminology) you can see that the rear-facing square-shaped bedroom has a window facing into the garden, making the overall floor plan an L. The shared walls with the neighbours match up about with the second floor floor plan's extreme left and right edges.

The original design on these Victorian terraces is typically an L shape, where the upright of the L had the kitchen in it, and the base of the L is the main block of the house. This allows the room at the back of the main block to have a window facing back into the garden for light. Many have subsequently been extended for extra space and to add bathrooms, which were not originally present. Partially or completely filling in the corner of the L is popular.

[PaulDavisThe1st]

OK, I see what you mean now. It's a very subtle L :)

I am extremely familiar with this shape - my sister lives in one just like this in Walthamstow (prolly not worth 2M yet though).

[michaelt]

It's subtle - but it's an extra 7m of exposed wall on a house that would otherwise only have 10m of exposed wall (the plots being about 5m wide)

[andrewaylett]

The L comes at the back of the property -- most visible on the first floor of the floor plan linked. Someone's roofed over the side passage on the ground floor to make a bigger kitchen and knocked the two main rooms together to make a larger living room.

That design of terrace is exceptionally common in the UK, where each pair of houses is mirrored, with a kitchen out the back and a side passage letting light into the middle room on each level.

[switch007]

(Brits, don't look at the sale history of that house. You'll get depressed)

[badpun]

In Poland, some of the houses where historical exterior by law needs to be preserved are insulated from the inside. Of course this eats into the square footage of the building.