I live in a 2 storey first floor flat, along with my neighbours in the flat opposite. There are 2 flats and 4 people on this floor. My neighbour a gentleman in his 70s and I are blue badge disabled. We find it increasingly hard to use the stairs. The stairwell is 35 inches wide. Acorn can fit a chair 12 inches wide when folded. We are hitting a brick wall with our housing association because it is the only exit from the flats and the stairlift will be considered an obstruction. you can only get one person at a time down these stairs anyway. I do not understand the problem. 
 

It looks like the housing association is taking the fire safety advice offered by the guidance available see the following example.

http://www.westyorksfire.gov.uk/uploads/assets/sitepoint/pan/fireProtection-FS/FS-PAN043-StairLiftsEvacuation.pdf