· Guidance
HCD publishes its updated ADU Handbook (March 2026)
The Department of Housing and Community Development updated its ADU Handbook to reflect the laws that took effect January 1, 2026. Its proportional-fee example: a 1,000 sq ft ADU next to a 2,000 sq ft home pays 50% of the fee a new home would pay. Our models use 2,000 sq ft as the example primary-home size unless you enter your own.
This updated ADU Handbook references the law as amended by recent legislation that went
Added Oct 18, 2026.