Mould-Whose Responsibility?

[pastafreak]

I own a 2-storey maisonette in a 4-storey building that contains 16 flats. I am on the upper 2 floors. The building is around 40 years old,and of concrete ( I think) construction. I can have the heat on for hours,and the upstairs will never get comfortably warm.
I-and others in the block-have been plagued by black mould for years. I have had it for the past 3-4,but I know others had the problem 6 years ago when I first moved in. There have been complaints,and the management had cavity wall insulation installed over 2 years ago. It has not made a bit of difference. We all tackle our flats with various treatments-yet the problem persists. As far as I know-management is unwilling to do anything to help individual properties.
Assuming the mould is due to the building itself-what recourse do we have?

I am posting this both here,and in Law.

[Bambiagain]

Don't know about the legal bit, but I believe cavity wall insulation can make the problem worse, not better. Your need to ventilate regularly (windows open every day, regardless of weather, for a reasonable time). But the concrete outside can stop the building "breathing", thus keeping the mould inside.