If they are finding homeowners which are not renting them, is that not a good thing?

The purpose of this regulation is to provide cheap rent for the poor. Not to enable "the rich" to acquire new real estate which they then proceed to not rent out at all ... Increasing the number of homeless.

Now of course this legislation "prevented that", by refusing owners do this while tenants are in the apartments. Except the net result seems to be when tenants do leave, the apartments are taken out of the housing market altogether, exacerbating the already pretty critical problems.

And in the German press you will find accounts of pressure tactics (such as schemes to force tenants into default, "using" things like a divorce to kick people out (man signed contract, woman stays in apartment, gets kicked out when man refuses to pay but woman is not allowed to sign contract in her own name), creating critical maintenance problems ...) to create that situation.

So no, that is a very, very bad thing.

Apartments aren't kept out of the housing market, actually. If they are, then the Vancouver solution is very effective - a 1% tax on the value of the property if not occupied.

The key thing here is supply and demand. If there is no profit to be made in renting out the property, then there is little reason to buy them up, in actuality. The exception is large companies that buy up a large amount of properties to manipulate the markets, but this has already been thinked of.

The main result of this if the unoccupied tax is used when necessary is a fall in the value of properties. This is a good thing for everyone that doesn't own a property that is unoccupied. This is what is wanted.

> If they are, then the Vancouver solution is very effective

Whatever is going on in Vancouver, it isn't effective (at controlling rent prices)

Whatever was done in Vancouver wasn't done to control rent prices. It was done to control vacant buildings. It was successful at that.

Hint - those two are related. If rental prices go down, you know supply has increase (or demand has decreased).

> If they are, then the Vancouver solution is very effective

Because rent could be considered affordable in Vancouver ? In which Canada do you live ?

The point of occupation was vacancy. Rent control is used to lower rent, and vacancy taxes are used to enforce vacancy. These are two separate effects and goals.

> the apartments are taken out of the housing market altogether

are the apartments just kept locked up?

Not that I know Berlin's situation, but hypothetically they could be converted into Airbnbs which end up competing with local hotels instead of rentals.

I know rental stock immediately opened up in Dublin when the pandemic started, for example, before such a large increase would have arisen from renters leaving the city for suburbs.

But, people are not buying it, companies are. Most known offenders are Akelius and Deutsche Wohnen, who just buy those apartments for cheap, wait until the renters leave (or make them leave), then renovate the apartment and rent for 4 times the price. The rich is getting richer, while people are being screwed.

Which is why the ruling alliance is trying to expropriante all entities with more than 3000 units. That's a nuclear options but it certainly fixes the issue.