Home › Glossary › Floor Area Ratio (FAR)

Floor Area Ratio (FAR)

Floor area ratio is a building's total floor area divided by the area of the lot it sits on. Zoning codes use it to limit how much building can go on a piece of land.

A FAR of 1.0 allows floor area equal to the lot size. On a 10,000 square foot lot, that could be a one-storey building covering the whole lot or a two-storey building covering half of it. A FAR of 2.0 on the same lot allows 20,000 square feet.

Each jurisdiction defines which spaces count toward FAR. Basements, garages, attics and mechanical rooms are often treated differently, so the same building can have different ratios under different codes.

FAR is based on the floor area definition in the local zoning code, not on appraisal rules, so the figure used for a permit can differ from a home's listed square footage.