But most homes in the UK are single family homes (66%) and women changed from having 2.4 kids on average in 1970 to 1.66 in 2021, so you would expect household size to fall.

Yes, and if the number of households stayed the same then they wouldn’t need more housing. But, that’s not what is happening.

So when they say things like this: “the UK’s homes-per-capita ratio actually exceeds the US’s.” they are ignoring the differences in household sizes between the two countries.

> Article suggests there’s a 1:1 relationship between population size and number of housing units needed

From the OP: Over the last 25 years, there has not just been a constant surplus of homes per household, but the ratio has been modestly growing while our living situations have been getting so much worse.

That's the ratio of homes to households, not to individuals. (Also, it's linear, not 1:1, but I assume that's what you meant.)

They use population not number of households in many places such as:

“the UK has roughly the average number of homes per capita: 468 per 1,000 people in 2019.”

“even though its population is roughly the same as it was 70 years ago”

“the UK’s homes-per-capita ratio actually exceeds the US’s.”

The last one is why I brought up the US household size. 2.36 vs 2.67 is a huge difference requiring a great deal of extra housing stock. IMO, using households once at the beginning then swapping to population was intentionally deceptive.

Sometimes even less than 1. For much of my childhood, the middle-class aspiration was a second home… though implicitly for a family rather than for an individual.

I have since known one single (in both senses of the word) person to briefly rent and live in an apartment despite also owning a detached house, due to an injury making commuting hard.

And if you make housing more affordable, household size will drop further, as fewer people choose to live together purely for economic reasons. For example, housing is pretty affordable in Finland, and the average household size was 1.93 in 2022.

Yes, a lot of people with roommates or stuck with family would move out if it were not for the high cost of housing

Yea, though in a good way. Not needing roommates is what happens when a housing shortage goes away.

In fact this drives most of the shortage in the developed world, especially in big cities. In many apartments there are 1 or 2 people (plus maybe a dog) living where there used to live 10 (ok, 5) half a century ago.

My parents used to sub-let back decades ago... So even that increased the number of people per unit. I don't think outside room mates that is popular anymore either. Which means more units are needed.

It can also have 0, if it's not being lent out, if it's a summer home, etc.

Housing might also not exist in locations where it's desired.

Housing might be the _wrong_ type for what a prospective occupant / area needs.

One size does not fit all.