Question 1

What is floor area ratio (FAR)?

Accepted Answer

Floor area ratio is the ratio of a building's total gross floor area to the area of its lot. A FAR of 1.0 means you may build floor area equal to the lot size — as a single story covering the whole lot, two stories over half of it, and so on. It is the primary control zoning uses to cap building bulk, working alongside height limits, setbacks and lot coverage.

Question 2

How do you calculate maximum buildable area from FAR?

Accepted Answer

Multiply the lot area by the allowed FAR. A 10,000-square-foot lot with a FAR of 1.5 permits 15,000 square feet of gross floor area. What counts as gross floor area varies by jurisdiction — basements, parking, mechanical space and balconies are sometimes excluded — so always check the local definition before you rely on the number.

Question 3

What is lot coverage and how is it different from FAR?

Accepted Answer

Lot coverage is the percentage of the lot covered by the building footprint — a two-dimensional limit on how much ground the building occupies. FAR limits total floor area across all stories. A tall, small-footprint tower can have high FAR and low coverage; a single-story big-box building the reverse. Most sites are constrained by both at once.

Question 4

How do you calculate required parking?

Accepted Answer

Zoning sets a parking ratio by use — commonly one space per 250 to 300 square feet for retail and office, one per 100 for restaurants, and one to two spaces per dwelling unit for housing. Multiply the floor area or unit count by the ratio and round up. Many cities have reduced or eliminated minimums near transit, so confirm the current local code, which changes often.

Question 5

What is density in dwelling units per acre?

Accepted Answer

Density is the number of dwelling units divided by the lot area in acres (lot square feet ÷ 43,560). A 20,000-square-foot lot with 8 units is about 17.4 units per acre. Residential zones cap density this way in addition to, or instead of, FAR — so a project can be limited by unit count even when floor area is available.

Use	Common minimum	Notes
Office	1 space / 300 sf	General business; medical is higher
Retail / commercial	1 space / 250 sf	Shopping centers sometimes 1/200
Restaurant	1 space / 100 sf	Driven by seats and assembly load
Medical / dental	1 space / 200 sf	High visitor turnover
Warehouse / industrial	1 space / 1,000 sf	Low occupancy per area
Multifamily residential	1–2 spaces / unit	Often reduced near transit
Single-family	2 spaces / unit	Usually a garage plus driveway

FAR, Lot Coverage & Parking Calculator

The Three Limits, and How They Interact

Typical Parking Ratios

Frequently Asked Questions