Fair rents is it that complicated

Last night I went on one of my question sprees asking people what they thought affordable housing really meant. Most people thought it was being able to buy housing at affordable prices but because of today's housing prices rises it wasn't viable. So why does the government keep on about it and why don't they make it easier for people to buy instead of these developers making huge profits from the working class. Some thought it was the governments way of dealing with unsocial housing, whatever that meant but I was outside the opera when I asked the question. Mostly people wanted to ask if there was any government ideas about fair rents. To me this comes under the heading of affordable housing. Here in London getting a flat at a fair rent is virtually impossible and with house prices rising by about 2.5 every quarter buying one is getting much harder for everyone. So the only option for most is to rent but with landlords seeing the opportunity to make money do so. So my question is can the government make good on their promise of affordable housing by putting a ceiling on rents. Just an idea because this would not only make it easier for people that have jobs but may make it easier for homeless people to get much needed accommodation. Anyway these are just my thoughts