So I know in London any new housing development has to allocate part of the properties for shared ownership or social housing, To be able to get planning approval.

Seems very reasonable because property developers make a lot of money selling luxury homes. And also in a lot of places the development is made after demolishing "unsightly" high density social housing.

Often with far fewer homes than there were there originally.

The social housing may be in a separate apartment block in a large development or the less prestigious lower floors.

If you pass by a development it's often obvious what the poor door is.

I've seen one where the social housing residents can't come in through the main entrance but instead goes through the utilities entrance, past the bin storage.

The justification I normally hear about it is that the private home owners will pay high service charges for things like concierge, swimming pools, gyms landscaped gardens, etc etc.

But honestly this seems like an excuse. Like people aren't asking for services for free.

The architecture of their home is telling them that they are inferior every time they enter their homes.

I find it hard to imagine the scenario where a developer is presenting their plan to the council and saying: "this is the door for the poor people"

But then again, I can imagine the arguments of "this is how it is always done"