What happens if you skip the permit (and you needed one)
- Stop-work orders in Redlands carry $100–$500 fines per violation day; unpermitted ADUs are often cited when a neighbor complains or during title work — cumulative fines can reach $5,000–$15,000.
- Title insurance companies will exclude the unpermitted ADU from coverage, making resale nearly impossible and forcing you to remediate (permit, inspections, fines) before close of escrow — often costs $8,000–$20,000 in back fees and corrections.
- Refinance and HELOC lenders require clear title and permitted structures — an unpermitted ADU kills both, locking you out of equity access for 5–10 years until you permit it retroactively.
- Homeowners insurance may deny claims on the ADU structure or deny coverage of the whole property if the ADU is discovered — a $200,000 structure becomes a $200,000 uninsured liability.
Redlands ADU permits — the key details
California state law (Gov. Code § 65852.2, as amended by AB 881 in 2021) has rewritten the ADU rules that Redlands can enforce. The state law is mandatory and preempts local zoning — meaning Redlands cannot enforce setback rules, lot-size minimums, parking requirements, owner-occupancy rules, or design-review delays that conflict with the state standard. The state allows one ADU per lot on any residential property, plus one 'junior ADU' (smaller, sharing a kitchen with the main house) in addition. Redlands' local ordinance remains on the books but is subordinate to state law; the City's role is to process permits quickly and ensure the ADU meets health/safety codes (IRC, NEC, plumbing code), not to impose discretionary restrictions. Per Redlands Municipal Code Chapter 17.64 (ADU regulations), the City will approve any ADU that complies with setback minimums (typically 5 feet from property line for detached), has a separate entrance, provides egress per IRC R310 (minimum 5.7 sq ft unobstructed exit), and has utilities (water, sewer, electric, gas if applicable) properly metered or sub-metered. This is a 'ministerial' review, meaning the City checks the boxes and approves or denies within 60 days — no discretion, no design competition, no negotiation.
The Redlands permit process is online-friendly and relatively fast. You file through the City's permit portal with a complete application: site plan (showing setbacks, lot dimensions, utility locations), floor plans (with egress windows labeled), electrical and plumbing schematic (sub-meter locations), and a standard ADU checklist. The City's permit team will conduct a 14-day staff review, then one public hearing is required only if a neighbor protests in writing. Most Redlands ADUs clear review in 30–45 days without a hearing. Plan-check corrections are common (electrical sub-meter location, egress window dimensions, foundation details), but Redlands' staff is known in the region for being reasonable and responsive. The 60-day clock (per AB 671) starts the day you submit a complete application; if the City wants to extend review, they must do so in writing with stated deficiencies, and you get 14 days to respond. This is substantially faster than typical design review in neighboring Fontana or San Bernardino, where ADUs can take 4–6 months through discretionary processes.
Utility setup is critical and often the first bump in the road. Redlands Water Department and San Bernardino County Sanitation District (which serves parts of Redlands) both require separate meters (water) and separate sewer taps (or sub-meter/allocation proof) for ADUs. The cost of a separate water meter is $1,500–$3,000; a separate sewer tap (if not already present) can run $2,000–$5,000 depending on distance to main line. If your lot is already served and you're doing a garage conversion, you may be able to sub-meter instead of installing a full tap — that's $500–$1,200 and avoids the big cost. You must show utility letters of availability and design in your permit application; the utility companies issue these within 2–3 weeks and will flag if a new tap is impossible (rare in Redlands proper, more common in foothill areas). Redlands also requires that any detached ADU be on a separate parcel from the main residence for property-tax clarity, or you must file a record of assessment (Assessor's Office supplies the form) stating that the ADU value is being recorded separately. This is unique to Redlands and reflects CA Prop 13 interpretation — some counties don't require it, but Redlands' Assessor is strict about it, and skipping it can cause reassessment audits later.
Setback and lot-size rules in Redlands are state-compliant and relatively flexible. A detached ADU must be set back 5 feet from front and side property lines and 15 feet from the rear if the rear lot backs onto another property; corner lots have the same rules. The minimum lot size per state law is 3,500 sq ft; Redlands allows ADUs on lots smaller than the city's standard zoning minimum (which ranges from 7,500 sq ft for standard residential to 15,000 sq ft in some foothill zones). A garage conversion or 'ADU within a structure' (e.g., above garage, second story of existing house) has no lot-size minimum and can be built to the existing footprint — no setback increase required. Redlands also allows junior ADUs (max 500 sq ft, no separate kitchen) in any residential zone; junior ADUs have no setback increase or lot-size requirement, making them an option for tight infill lots. Foundation rules: detached ADUs on granitic foothills (east and north Redlands) must meet IRC R404 (shallow foundation) or R403 (deep foundation, rare here); frost depth in the mountains is 12–30 inches, so pier-and-grade-beam is common. Coastal areas and valley floors have minimal frost and no special foundation requirement. The City will request a soils report ($600–$1,500) if your lot is in a mapped geotechnical area; most of Redlands' residential zone does not trigger this, but foothill parcels often do.
Final inspections and occupancy approval involve five standard checks: foundation (if detached), framing, rough trades (plumbing, electrical, HVAC), insulation/drywall, and final. The City also requires a separate planning sign-off (confirming setbacks, lot-size, owner-occupancy waiver per state law) and utility company final approvals (water meter on, sewer tap commissioned). Timeline is typically 6–12 weeks from permit issuance to occupancy permit if there are no plan-check corrections and inspections pass on first call. Most Redlands ADUs that are owner-built (owner as GC, using licensed subs) move faster than contractor-built projects because the owner is responsive and on-site. If you hire a general contractor, expect 10–16 weeks — contractor scheduling, material delays, and re-inspections if subs are not present at inspection time all add to the clock. The City does not require a specific 'ADU inspector' — standard building inspectors do the work — so no additional fee or delay there. Final occupancy permits are issued within 3 business days of the final inspection pass; you can occupy immediately. Renting the ADU requires no additional permit, but you must notify the City of any change in occupancy status (this is administrative, not enforcement-heavy in Redlands).
Three Redlands accessory dwelling unit (adu) scenarios
Why Redlands ADU permits are faster than San Bernardino and Fontana — the ministerial vs. discretionary split
California state law (AB 671, effective 2018) imposed a 60-day clock on ADU permits and required cities to use 'ministerial' review — meaning no discretion, just a checklist. Redlands adopted this into its 2019 update to Chapter 17.64 and built an online portal workflow that processes qualifying ADUs in 30–45 days. San Bernardino and Fontana, by contrast, still require conditional-use permits (CUP) or variance requests for ADUs in some zones, which adds a public-hearing phase and stretches timelines to 4–6 months. The difference is not a state-law gap; both cities are legally required to do ministerial review. The difference is budget and staffing: Redlands hired a dedicated ADU plan-check team in 2019, while San Bernardino and Fontana handle ADUs through standard design-review channels with existing staff. Redlands' online portal also auto-flags incomplete applications (missing utility letters, insufficient setback dimensions) before a human touches the file, so corrections happen in days instead of weeks.
A second angle: Redlands Assessor's Office published a detailed 'ADU Prop 13 guidance' document in 2020 that other San Bernardino County cities don't have. This document clarifies that the ADU structure and interior are separately assessed from the main residence and land, which is crucial for Prop 13 reasons — it means your annual tax increase is on the ADU improvement value only, not on the land value, which can save $200–$400 per year. Fontana's Assessor is murkier on this, and many Fontana ADU owners have faced surprise reassessments of the entire parcel. Redlands' clarity is a genuine advantage and reflects the City's commitment to making ADUs financially predictable.
Redlands also allows owner-builder status for ADUs (with licensed contractors for trades), whereas San Bernardino requires a general contractor for some ADU types. This saves 10–15% on labor for DIY-minded owners or those using family and trade-licensed friends as subs. The cost savings on a $100,000 ADU project can be $10,000–$15,000.
Geotechnical risk in Redlands' foothill ADUs: how to avoid surprise foundation costs
Redlands' geography splits into three zones: coastal plain (elevation 1,000–1,500 feet, stable alluvial soil), foothills (elevation 1,500–3,000 feet, granitic bedrock, steep slopes), and mountains (3,000+ feet, loose talus, deep frost). The foothills zone (east and northeast Redlands, San Timoteo Canyon, Oak Glen areas) is where ADU surprises happen. Granitic soils in these areas are prone to creep (slow downslope movement), shallow groundwater in seasonal canyons, and limited bearing capacity. Redlands requires a geotechnical report for any ADU (detached or conversion) in a mapped hazard area — this is a $1,500–$2,500 cost that many homeowners don't budget for. The report takes 3–4 weeks to procure (a geotech engineer does a site visit, soil boring if needed, and writes a recommendation for foundation type). The report is required before the City issues a permit, so you can't start construction on spec.
The smart move: before you file a permit application, get a preliminary geotech opinion from a local engineer ($400–$600 phone/site visit, no boring required) to assess if your lot is in a hazard zone. Redlands' planning department map shows the hazard zones online or by phone. If you're in a zone, budget for the full report upfront. If you're on the coastal plain, geotechnical work is rare. Most Redlands geotechnical issues result in recommendations to use deeper piers (pier-and-grade-beam instead of slab-on-grade), which costs an extra $2,000–$4,000 in foundation labor — manageable if planned, shocking if discovered mid-construction.
One more foothill rule: any ADU in a designated 'very high fire hazard severity zone' (mapped by CAL FIRE) must include 5/8-inch drywall on all interior walls, automatic sprinklers if the structure is within 30 feet of property line or if total lot square footage (main + ADU) exceeds certain thresholds, and defensible space (cleared brush 30–100 feet around structures). Redlands' foothill areas (Oak Glen, Forest Falls) are heavily in these zones. Sprinklers add $3,000–$6,000 to a 400 sq ft ADU and are often the deal-breaker for tight budgets. Check CAL FIRE's map for your address (free online) before committing to a foothill ADU project.
City Hall, 35 Citrus Ave, Redlands, CA 92373
Phone: (909) 798-7500 ext. 7500 (main line; ask for ADU/Building permits) | https://www.cityofredlands.org/services/building-permits (search 'Redlands building permit portal' if URL changes)
Monday-Friday 8:00 AM - 5:00 PM (closed city holidays; online portal available 24/7)
Common questions
Does California state law really override Redlands' zoning rules for ADUs?
Yes. Gov. Code § 65852.2 (as amended by AB 881 in 2021) is mandatory statewide and preempts local zoning, parking, owner-occupancy, and design-review rules. Redlands cannot block an ADU based on lot size (if above 3,500 sq ft), setbacks (if they meet IRC minimums), parking (waived for qualifying ADUs), or requiring the owner to live in the main house. Redlands' local ordinance (Chapter 17.64) remains on the books but is subordinate to state law. If Redlands denies your ADU on grounds that conflict with state law, you can appeal to the state housing regulator (HCD) or sue. In practice, Redlands staff knows this and does not deny compliant ADUs — they process ministerially.
Can I build an ADU on a lot smaller than 3,500 square feet?
No, not for a detached or new ADU structure. State law sets 3,500 sq ft as the minimum lot size for a new ADU. However, you can convert an existing structure (garage, accessory building, second story of the main house) into an ADU on any lot size — the structure must already exist. Junior ADUs (shared kitchen, max 500 sq ft) also have no lot-size minimum and can be built on any residential lot. Redlands does not add restrictions beyond state law, so the 3,500 sq ft rule is the floor everywhere in the city.
Do I have to live in the main house if I build an ADU and rent it out?
No. State law (AB 881) eliminated owner-occupancy requirements in 2021. You can own the property, build an ADU, and rent both the main house and ADU to tenants. Redlands does not impose an owner-occupancy requirement. You do need to notify the City if you rent the ADU (administrative, no additional permit required), and you must comply with California's ADU rental laws (e.g., you cannot impose fees or restrictions that differ from the main house, you cannot require a co-signer without reason, etc.).
How much will the permit and plan review cost for an ADU in Redlands?
Redlands' permit fee for ADUs is typically $1,200–$2,000 depending on square footage (fees are often $0.50–$1.00 per sq ft of ADU square footage, calculated at issuance based on valuation estimate). Plan review is usually $300–$500. Total permit and plan-review cost: $1,500–$2,500. This is lower than design-review projects in San Bernardino or Fontana (which can reach $4,000–$6,000) because ADU review is ministerial. If you require a geotechnical report (foothill lots), add $1,500–$2,500. If you need utility availability letters ($200–$500 each from water/sewer), that's additional. Budget $2,000–$5,000 total for permit, plan review, and engineering.
What is the timeline from filing to occupancy permit in Redlands?
For a straightforward detached ADU on a coastal-plain lot, expect 6–10 weeks from complete application to occupancy permit. This includes 2–4 weeks for plan check, 1–2 weeks for any corrections, 1 week for permit issuance, and 4–8 weeks of construction/inspections (depending on your contractor's pace). Geotechnical-hazard zones add 2–4 weeks to plan review. Most Redlands ADUs clear the 60-day state clock and issue within 45 days of a complete application if no major corrections are needed. Construction and inspections are your timeline variable, not the City's.
Do I need a separate sewer connection, or can I sub-meter/allocate the existing line?
Redlands Water Department and San Bernardino County Sanitation District (which serves parts of Redlands) allow sub-metering and allocation for sewer if the main line is already on-site and has adequate capacity. If you're doing a garage conversion or second story on the existing main house, allocation is typical and costs $0–$500 (administrative). If you're building a detached ADU 80+ feet from the existing sewer tap, San Bernardino County Sanitation District may require a new sewer tap (cost $2,000–$5,000, 2–4 week process). The City's utility clearance letter will clarify this. Always request the utility availability letter early (Week 1 of permitting) — it may change your project cost significantly.
Can I build an ADU myself, or do I need to hire a contractor?
California B&P Code § 7044 allows owner-builder status for ADUs (you can be the general contractor and pull the permit under your own name). However, all electrical, plumbing, and gas work must be done by a licensed contractor — you cannot do these trades yourself even as owner-builder. Redlands does not add restrictions beyond state law. Many Redlands ADU owners act as owner-builders and hire licensed subs for MEP (mechanical, electrical, plumbing), which often saves 10–15% on labor compared to a full general contractor. You must be present and responsible for the work; the City inspector will not approve final occupancy without evidence that all subs are licensed (copies of license cards, insurance, and lien releases).
Will my property taxes increase significantly if I build an ADU?
Yes, but Redlands' Prop 13 rules are clearer than most California counties. Your annual tax increase will be approximately $1.25% (effective property tax rate) times the assessed value of the new ADU structure and interior improvements. For a $100,000 ADU, expect a $1,250/year tax increase, not a reassessment of the entire lot. Redlands Assessor's Office publishes guidance confirming this (the ADU is a separate parcel for assessment purposes, using Assessor Parcel Number suffix). Some counties reassess the land value too, which would double the increase — Redlands does not. Document your ADU separately (record of assessment form, available from Assessor) to lock in the separate-improvement assessment and avoid reassessment surprises.
Can I build a junior ADU and a standard ADU on the same lot?
State law allows one standard ADU (or one junior ADU) per parcel, plus one additional junior ADU. So yes, you can build one standard ADU (800 sq ft full kitchen) and one junior ADU (500 sq ft shared kitchen) on the same lot if you have the space and the main house remains. Redlands has no local restrictions beyond state law. However, on a typical residential lot (5,000–7,500 sq ft), space for both a main house, a standard ADU (400–800 sq ft), and a junior ADU (300–500 sq ft) is tight. You would need a lot closer to 10,000 sq ft to comfortably fit all three structures with required setbacks. Check your lot dimensions and setback rules with Redlands Planning before designing two ADUs.
What if my neighbor objects to my ADU — can they stop the permit?
Redlands' ADU permits are ministerial, not discretionary. Neighbor objections do not trigger a full design-review process or delay the permit. If a neighbor files a written protest (rare, and allowed only during the public-notice phase), the City must hold a single public hearing but still approves or denies based on code compliance, not neighborhood preference. In practice, most Redlands ADUs are approved without a hearing because neighbors do not object or the City's staff review is complete before the notice period ends. Even if a hearing occurs, if your ADU meets code (setbacks, egress, utilities), Redlands must approve it. You cannot be blocked by a neighbor or local opposition.