Let housing association tenants buy there home after 10 years of living there.

Change the law, so that people in rented housing association can buy there homes after being in them for a number of years, like they do for counsel tenants. Its unfair that i have been living in my home for 15 years paying rent, and they won't allow me to buy the home i am in. I live in Wakefield. I believe they do in some parts of the county, but not here. law should be changed to allow anyone to buy after they have lived there for so long.