[vgetr]

They could, but then the costs will just be passed down to the tenants (i.e. increased rent).

[Dylan16807]

Even with the cost of insulation upgrades added to the rent, that's still cheaper total.

[antepodius]

Depends on how much the costs of insulation upgrades are blown out of proportion by being mandated.

[Dylan16807]

For something that has to be done to most houses, I would expect a pretty large and competitive market.