Immigration seems to be the answer, but not so easy to pull off. Are there countries that have done this well? I would argue that for a long time, the US has done this quite well until maybe the last decade.

Australia and New Zealand have 30% of population born in other countries. Housing growth seems to be keeping up in my city (Christchurch).

I'm unsure if immigration is a sustainable solution - immigrants also get old and retire. But perhaps it works out because immigrants have more kids than people that were born here?

I'd recommend Australia, for anyone considering moving, because it has better economics and a wider choice of locales and jobs.

Unless you want to Balkanize yourself immigration is probably not the answer.

The US is also probably not the best example because it’s a very different situation. Even in the 19th and 18th centuries natural birth rates accounted for about half of the population growth in the US.

The current projection for the UK is that between 2021 and 2036 immigration will account for 92% of the population growth, and based on the previous 2-3 years this might actually be an underestimate.