If there are more people, there'll be more competition for homes and prices will rise.
I've asked the ONS and the government what statistics Raab was referring to.
Sa estimates that 1% immigration reduces house prices by 1.7%.
But even if it is as much as 20% in 25 years, house prices have grown 350% overall in that time, so it's a pretty minor factor.
That level could never be achieved even if it was desirable, so the 20% figure isn't measuring anything believable even if it is accurate.
Without them, we'd have built far fewer homes in the last 25 years.