What other kind is there?

The design for the rebuilding of the fire-damaged area in Edinburgh's Old Town has been unveiled. We are told that:

The scheme envisages a range of uses, including offices, nightclubs, residential space and possibly affordable housing.

Hang on a moment; what is "affordable housing"?

If someone is going to live in these homes it follows that they are affordable. I have a horrible feeling that these houses will be subsidised by the taxpayer so as to make them "affordable" to the lucky residents, thus making other things not affordable to those who pay for their own homes.