As part of a type 3 FRA I have came across a 1970s block of flats 3 stories in height the upper story has 2 bedrooms accessed from the lounge with the kitchen and bathroom at the front near the entrance. There is no alternative MOE.

 

The detection is LD2 grade D1 Is there a requirement to retrofit any further protection?   

Nor under the Fire Safety Order as it's inside the dwelling, nor under Building Regulations as they aren't retrospective. Are they rented or owner occupied? Assuming you are in England LD2 exceeds the statutory minimum of LD3 for rental properties.