Many people or developers have chopped up their properties, so there isn't much room for a vege gardens these days. Overseas they tend to have community gardens or allotments.
there is always room to grow vegetables, hanging baskets are good for tomato's and strawwberries. ?potato bags can be brought to grow spuds in. ?many vegetables can be grown in containers without the need for a big garden.
Yes but you need quite a lot of land if you actually want to live off it for a family, and not buy many vegetables in. Also have to deal with crop rotation etc.
Vertical gardening is the answer
In one city in the US they have a trial in one city where there is a large glass building with story upon story of hydroponic gardens... could adapt that to the town house court yard.... may end up higher than the house mind you.