Zoning & entitlements
Density bonus
The percentage increase above a site's maximum allowed density that cities must grant for qualifying affordable set-asides under Gov. Code § 65915.
Definition
Under the State Density Bonus Law, Government Code §§ 65915–65918, a housing development of five or more units that reserves a qualifying share of affordable, senior, student or shared housing earns a mandatory density increase above the maximum allowed by zoning and the general plan. The base scale starts at a 20% bonus for a 5% very-low-income or 10% lower-income set-aside and slides up to 50%; a 100%-affordable project earns an 80% bonus — and unlimited density within a half mile of a major transit stop.
The bonus is a state mandate that applies in every city and county, charter cities included, and it arrives bundled with concessions, waivers and statutory parking caps. Rental affordability covenants run 55 years.
Why it matters in an underwrite
The bonus units are market-rate — only the set-aside carries covenants — so on a 20-unit base, a 15% very-low-income set-aside (3 affordable units) can add 10 market-rate units at a 50% bonus. Fractions round up at every step. The gating trap is § 65915(c)(3): sites with rental history in the past five years owe replacement units on top of the set-aside, which can swallow the bonus value on former rent-controlled parcels.
Sources & related guides
See also
See the term in the law itself
Read the controlling text in the Code Library, or ask the AI how it applies to your project.
Last reviewed 2026-07-29. General information, not legal advice.