Upgrading non fire compliant material to compliant fire-resistant materials which meet regulations and legislation's.

BS 8579 requires balconies above 11 meters to limit its combustibility (i.e. A1 or A2-S1-d0 as classified by BS EN 13501-1 in accordance with Regulation 7). 

Importantly this is applicable to stacked balconies with any height. Emphasis on the balconies to limit and prevent the spread of fire to the surround and structure.