Everything homeowners ask about building an ADU in Upland — answered with 2026 data.
Yes, ADUs are allowed in Any lot in a residential or mixed-use zone (building-permit-only path); lots zoned for single-family or multifamily residential use (ADU-permit path); JADUs on single-family lots only in Upland, CA. The maximum size for a detached ADU is 850 sq ft (studio/1-bedroom); 1,000 sq ft (2+ bedrooms); an 800 sq ft ADU can never be precluded by lot coverage, FAR, or open-space standards. Attached ADUs can be up to 850/1,000 sq ft by bedroom count, further limited to 50% of the existing primary dwelling's floor area (never below 800 sq ft). Upland has an ADU-friendliness score of 6/10. Check our full Upland ADU rules page for complete zoning details.
ADU construction in Upland typically costs $160,000-$300,000. The cost per square foot averages $200-$350. Garage conversions are more affordable at $70,000-$150,000, while prefab ADUs cost $80,000-$180,000. Permit fees add Building permit and plan-check fees via the Development Services Department — confirm amounts with Building & Safety, (909) 931-4110 to your budget. See our detailed Upland ADU cost guide.
Detached ADUs in Upland can be up to 850 sq ft (studio/1-bedroom); 1,000 sq ft (2+ bedrooms); an 800 sq ft ADU can never be precluded by lot coverage, FAR, or open-space standards. Attached ADUs are limited to 850/1,000 sq ft by bedroom count, further limited to 50% of the existing primary dwelling's floor area (never below 800 sq ft). Junior ADUs (JADUs) have a cap of 500 sq ft within the single-family dwelling or attached garage. Maximum height is 16 ft detached (18 ft within 1/2 mile of major transit or on multistory multifamily lots, +2 ft to match primary roof pitch, max 20 ft); attached up to 25 ft or the zone limit, whichever is lower, max 2 stories; detached ADUs limited to one story. You are allowed up to Single-family: 1 ADU + 1 JADU per state framework; multifamily: interior conversions plus detached units per Gov. Code 66323 — confirm allowed combinations with Planning, (909) 931-4130 on a qualifying lot.
Rear setback: 4 ft minimum; none for same-location/same-dimension rebuilds. Side setback: 4 ft minimum; 15 ft on the street side of corner lots. Front setback: 25 ft minimum front-yard setback (waived if it would preclude an 800 sq ft ADU). Note that garage conversions may be exempt from setback requirements if the existing structure is already within the setback area.
1 space per ADU (tandem/setback areas OK; unenclosed spaces 9x19 ft); waived within 1/2 mile of transit, historic districts, conversions, permit-parking streets, car-share within a block, or when filed with a new dwelling; no replacement parking for demolished garages. Many cities and states have been relaxing ADU parking requirements in recent years. In California, no additional parking is required for ADUs near transit.
Not required for ADUs permitted on or after Jan 1, 2020; required for JADUs (deed-restricted). Note that owner-occupancy rules vary by state law — California and several other states have eliminated this requirement for standard ADUs.
The ADU permit review timeline in Upland is typically 60 days from complete application (SB 543 deemed-approval applies from 2026). Plan check: Reviewed by Planning (zoning) and Building & Safety (CBC/CRC); design standards require matching materials/roof slope, 12-inch eave overhangs, privacy screening, down-lighting, and drought-tolerant landscaping; roof decks prohibited. Pre-approved plans availability: Yes — free, permit-ready pre-approved ADU plans for Upland residents; third-party architects may also submit Pre-Approved ADU Templates; site plan still required.
Average ADU rental income in Upland: 1-bedroom units rent for $1,950-$2,150/month, 2-bedroom units for $2,400-$2,600/month. Short-term rentals: No — ADUs and JADUs may not be rented for terms under 30 days regardless of when they were built; the city separately regulates short-term rentals via administrative use permit (Ch. 17.23.1). Expected ROI: 7-10% annual return (gross rental yield estimate).
The minimum lot size for an ADU in Upland is No minimum lot size, but lot-coverage caps apply by zone (35% in RS-15/RS-20 up to 50% in RS-4). This applies to detached ADUs — garage conversions and JADUs may have different or no lot size requirements.
Garage conversions are one of the most popular and affordable ADU options. In Upland, a garage conversion typically costs $70,000-$150,000. The key advantages are lower cost (no foundation work), potential setback exemptions, and faster permitting. Read our complete garage conversion guide.