GFA / NLA Efficiency Calculator
Gross-floor-area to net-lettable-area efficiency ratio and effective rent.
Calculator
GFA / NLA efficiency
How much of the gross floor area is actually lettable, and what the headline NLA rent works out to across the whole building.
How this is calculated
Efficiency is net lettable area divided by gross floor area. Effective rent on GFA spreads the NLA rent across the whole gross area (NLA rent multiplied by the efficiency ratio), which is useful when comparing a quoted NLA rate against a price or cost expressed on GFA. Typical office efficiency sits roughly between 75 and 85 percent; common areas, cores, plant and structure account for the balance. Confirm the area definitions with the landlord, since "NLA" and "GFA" are measured differently across buildings.