Can I Build an ADU in Poway?

Yes — by right

ADUs and JADUs are allowed by right in all residential and mixed-use zones; ministerial approval, no hearing.

1 ADU + 1 JADU

At least one ADU and one JADU per single-family lot (a conversion ADU may also be possible).

Conversion ADUs (≥1, up to 25% of units) + up to 8 detached

Conversions of non-livable space (at least 1, or up to 25% of existing units) plus up to 8 detached ADUs on a lot with existing multifamily — never exceeding the number of existing units. JADUs are single-family only.

Allowed

Up to 500 sq ft, within the walls of an existing single-family home (single-family lots only).

1,200 sq ft

A detached ADU may not exceed 50% of the main residence's floor area or 1,500 SF, whichever is less — but is never required to contain less than 1,200 SF (PMC § 17.08.180(A)(9)(b)). So 1,200 SF is the guaranteed detached allowance, above the 800 SF state floor.

50% of the main residence or 1,500 SF, whichever is less; never required below 1,000 SF (2+ bedrooms) or 850 SF (studio)

Attached ADU floor area ≤ 50% of the main residence (excluding garage) or 1,500 SF, whichever is less, but not required below 1,000 SF for an ADU with more than one bedroom or 850 SF for one with no bedroom, unless setbacks require.

800 sq ft

An 800 sq ft ADU must be allowed regardless of FAR/lot-coverage caps; a city also cannot cap an attached ADU below 850 sq ft (1,000 for 2+ bedrooms).

500 sq ft

16 ft

Detached ADU limited to one story and 16 ft above average grade; an ADU meeting the main residence's setbacks may instead reach the main residence's height. The 2019 ordinance predates the state 18/20 ft transit/multistory allowances, which now govern by preemption regardless of this text.

4 ft

A city cannot require more than 4 ft side or rear setback; conversions of existing structures are exempt.

4 ft

No front setback may block the mandatory 800 sq ft / 16-ft / 4-ft-setback ADU; otherwise per base zone

10 ft

A detached ADU must sit at least 10 ft from the main residence or other detached accessory building. State law sets no separation requirement and protects an 800 SF / 4-ft-setback ADU, so this 10-ft rule cannot be applied to block the state by-right unit; confirm application with Poway Development Services.

Up to 1 space

One off-street space per ADU, allowed as tandem/in setbacks, waived in the state cases (within ½ mi of transit, historic district, permit-parking areas, etc.); no replacement parking when a garage/carport is converted or demolished.

Yes — no parking required near transit & for conversions

No parking may be required within ½ mi walking distance of transit, in a historic district, for an ADU within an existing structure, within one block of car-share, or in certain permit-parking areas.

Not required

When a garage/carport is demolished or converted to build an ADU, replacement parking cannot be required.

Ministerial (by right)

No public hearing or discretionary design review for a qualifying ADU.

60 days

The agency must act within 60 days of a complete application — and the ADU is deemed approved if it does not.

Only for a JADU

No owner-occupancy requirement for ADUs (the prior sunset was removed). A JADU may require owner-occupancy, principally where it shares sanitation with the main house.

Waived under 750 sq ft

An ADU of 750 sq ft or less pays no impact fees (the 750 sq ft threshold itself is exempt under § 66311.5); larger ADUs pay fees proportional to the primary dwelling. JADUs (≤ 500 sq ft) are exempt.

Building permit

Only a ministerial building permit — no conditional use permit or discretionary design review for a qualifying ADU.