A place to live

I am trying to raise money to convert the loft in our housing association property. We live in a one bed flat with two young children and the housing have no properties to move us to also even if they did it would no longer be an assured tenancy like we currently have. This is so frustrating as we have the ideal space right above our heads in the form of a loft that is big enough for the whole family. We recently had a quote done which came in at £39,975 and the company said that this would add £300,000 to the property so for the housing association that own this property NHHG it should be a nobariner but apparently they have no schemes in place at present which seems a shame as other housing associations have recently tried and tested this and found it to be a great success. Please please please anyone out there if you can help or know anyone that can please do.