Building an ADU in Burbank. Rules, costs, timeline.

Taller than in most cities near it, and the number depends on how you attach it. A freestanding detached ADU is capped at 17 feet to any architectural feature, rising to 18 feet within a half-mile walking distance of a major transit stop or high-quality transit corridor — plus two more feet there to match your home's roof pitch. Build the ADU on top of a detached garage or accessory structure and BMC § 10-1-620.3(G)(2) allows 20 feet to the top of plate and 23 feet to any architectural feature. Attach it to the house and the R-1 table applies: 20 feet to plate and 30 feet to the top of a pitched roof, though a flat roof is capped at 23 feet.

Yes, by two routes, and this is the most useful thing on the page. Above a garage you have 23 feet to work with, which comfortably carries a two-story unit. Attached to the house you have 30 feet if the roof slopes at least 30 degrees — Table 10-1-603(A) footnote 3 sets that condition, and the City's own ADU handout omits it. A freestanding detached ADU at 17 feet is single-story on most plans, though note that the code sets a height, not a story count: the word "one-story" appears in § 10-1-620.3(G) only in the attic rule at G.5. State ADU law contains no story limit either, and HCD's March 2026 Handbook (p. 24) states that where a detached two-story ADU fits within the applicable height allowance and complies with the building code, a city cannot deny it on story count alone. Read that as HCD guidance rather than statutory text — Gov. Code § 66321(b)(4)(D) governs attached ADUs and expressly "shall not require a local agency to allow an accessory dwelling unit to exceed two stories." If a plan checker treats 17 feet as a one-story rule, ask which provision says so.

For new construction, 850 square feet for a studio or one-bedroom and 1,000 square feet with more than one bedroom (BMC § 10-1-620.3(F)(2)). Those are the state-mandated minimums a city may set, not a Burbank concession. A conversion is a different and much better answer. An ADU created inside your existing house or inside an existing accessory structure is a Gov. Code § 66323(a)(1) unit, and HCD is explicit that it "is not subject to unit size requirements" — no square-foot cap at all. Burbank agrees in its own text: § 10-1-620.3(F)(7) lets an accessory-structure conversion keep the greater of 850/1,000 or the existing structure's footprint, and F.8 allows another 150 square feet for ingress and egress. If you have a 1,200 square foot garage or workshop, do not shrink it to 1,000. There is also a local bonus on new construction: under § 10-1-620.3(F)(9), providing on-site parking stalls beyond the minimum required buys up to 120 more square feet in total — not per stall — on one ADU on the lot, a practical ceiling of 970 or 1,120 square feet. The trade is a recorded deed restriction running with the land that bars removing that parking for as long as the ADU exceeds the normal cap.

The code says one ADU plus one Junior ADU — § 10-1-620.3(B)(2) permits "no more than one ADU" on a single-family lot, and § 10-1-620.3(P)(2) allows one Junior ADU. State law is more generous. Gov. Code § 66323(a) requires the City to allow a conversion ADU, a Junior ADU and a newly built detached ADU of up to 800 square feet in combination, and HCD's March 2026 Handbook (p. 18) adds that a local agency must allow at least one further unit under Gov. Code § 66314 on top of those. Do the arithmetic and the state floor on a Burbank single-family lot is four units, not two. That fourth unit is HCD guidance rather than express statutory text, so put it in writing at pre-application rather than assuming it at the counter. Burbank's own text concedes the underlying point by opening § 10-1-620.3(A) with "unless otherwise preempted by state law."

The code caps you at two detached, and that cap is preempted. BMC § 10-1-620.3(O)(1) states that "no more than two (2) ADUs can be constructed on a lot with an existing or proposed multifamily dwelling structure(s)." Gov. Code § 66323(a)(4)(A)(ii) requires ministerial approval of up to eight detached ADUs on a lot with an existing multifamily dwelling, capped at the number of units already there. Separately, § 10-1-620.3(O)(2) allows conversions of non-livable space at 25 percent of existing units with at least one permitted, which does track state law. Note that Burbank's "unless otherwise preempted" savings clause sits in subsection B and does not reach subsection O.

Four feet from the rear and side property lines, and § 10-1-620.3(H)(1) is explicit that this applies "including ADUs constructed on top of a garage or accessory structure" — so the four feet holds at the second story too. Two provisions are worth more than they look. Under H.6, no setback is required where the ADU is built in the same location and to the same dimensions as an existing legal structure, "even when that structure has been demolished." And under § 10-1-620.3(H)(3), an unpermitted accessory structure can keep its legal nonconforming setbacks as part of a conversion, subject to the Building Official's health and safety review. Two more numbers matter as much on a normal lot: § 10-1-620.3(H)(4) requires 5 feet between building faces and 4 feet eave to eave, and stairs, landings and any balcony or patio more than 7 inches above grade take the full 4-foot setback (H.7, H.8). The front setback is the prevailing setback on your blockface rather than a fixed number — but it can never be the reason you get no ADU. Gov. Code § 66321(b)(3) provides that a front setback cannot preclude an ADU of at least 800 square feet, even if that ADU would sit partly or wholly inside the front setback, and Burbank codifies the same thing at § 10-1-620.3(H)(2)(b): show with dimensioned exhibits that an 800 square foot ADU will not fit elsewhere on the lot at 2-foot side and rear setbacks — the City will test that against a two-story option first — and an ADU of up to 800 square feet is allowed to encroach into the front yard. Note the trade in that subsection: anywhere you end up under 3 feet from a side or rear line, no openings are allowed on that elevation.

Usually not, and two categories are exempt absolutely rather than usually. A Junior ADU may never be required to provide parking at all — Gov. Code § 66334(a), and HCD is explicit that this holds even when the Junior ADU is converted from an attached garage. And no parking standard of any kind may be applied to a § 66323 unit: a conversion ADU, a Junior ADU, or the by-right detached 800 square foot unit. For everything else the baseline is at most one space per ADU or per bedroom, whichever is less, and six exemptions remove it: within a half-mile walking distance of public transit, in a historic district, part of the existing primary dwelling or an accessory structure, where on-street permits are required but not offered to your tenant, where a car share sits within one block — and, uniquely, § 10-1-620.3(E)(6), which waives parking outright if you can produce dimensioned plans proving there is no feasible location for it. Replacement parking is never required when a garage is converted or demolished in conjunction with the ADU (Gov. Code § 66314(d)(11)), though note Burbank narrows "in conjunction" to footprint overlap or a structure that impedes access to the ADU, a narrowing the statute does not contain.

Read this carefully before you accept a "no." BMC § 10-1-620.3(M)(1) bars an ADU on R-1 or R-1-H land inside the City's Mountain Fire Zones unless it is one ADU of no more than 800 square feet or one Junior ADU of no more than 500 square feet. But the Mountain Fire Zone is a Burbank Fire Department line drawn in the General Plan Safety Element — the Safety Element says the zones "are designated by the Burbank Fire Department" and never mentions CalFire or the state Fire Hazard Severity Zone system. It is not the same thing as a state Very High Fire Hazard Severity Zone, even though the City's own pre-approved plan page calls it a "Very High Fire Zone." Separately, Gov. Code § 66323(b) bars a city from imposing standards on the by-right units that the statute does not itself authorize, so neither the 800 square foot cap nor the either/or reaches any of the three: not a § 66323(a)(1) conversion ADU, which has no size cap at all; not the Junior ADU that the same subdivision delivers alongside it; and not the § 66323(a)(2) detached 800-footer. The either/or fails in particular, because state law requires the conversion ADU and the Junior ADU together rather than as alternatives. If you are in the foothills, ask for a written zoning determination.

More than the summaries suggest, and the local rule is on shaky ground anyway. BMC § 10-1-620.3(N)(1) caps R-1-H at one ADU or one Junior ADU — not both — and bars new construction of ADUs except for four routes: converting an existing permitted garage, converting an existing permitted guest dwelling unit, converting existing square footage within the main dwelling, and, the one most people miss, an addition to the main dwelling under N(1)(d), which is permitted so long as it sits outside the rear 35 feet reserved for horse keeping. Subsection N(2) separately says converting a storage building, shed, pool house, recreation room, barn, stable, corral or tack room "shall not be permitted." That is the most clearly preempted rule in the ordinance: Gov. Code § 66323(a)(1) guarantees one ADU per lot "within the converted space of a proposed or existing single-family dwelling or accessory structure," and § 66323(b) bars a city from applying any standard to that unit the statute does not list. The categorical bar on new detached construction runs into § 66323(a)(2) the same way. None of this has been decided in court, and Burbank's own subsection N opens "unless otherwise stated in the following or otherwise required by state law" — so submit the application, cite § 66323(a)(1) and (b) on the plans, and make the City put any denial in writing, which Gov. Code § 66317(b) requires it to do.

Because it has not been updated. BMC § 10-1-620 repeatedly cites "Government Code Section 65852.2" — at §§ 10-1-620.2(B), 620.3(B)(2), (B)(3), (E), (I) and (J)(2). State ADU law was recodified into Gov. Code §§ 66310 and following, and § 65852.2 no longer exists. That does not void Burbank's own development standards, but it does mean every state-law cross-reference inside the ordinance points at a dead section. If a rule is being applied to you by reference to § 65852.2, the live provision is somewhere in §§ 66310–66342 and it may not say what the old one did.

The planning application for an ADU is $1,728.42 on Burbank's adopted Fiscal Year 2026–27 planning fee schedule, effective July 1, 2026, plus a general plan maintenance fee of 20 percent of the application fee. Council resets these every July 1, so that figure holds through June 30, 2027. Building permit and plan check are valuation-based and Burbank does not publish them in a form you can compute from — get them quoted. On impact fees, BMC § 10-1-620.3(K)(2) bars development impact fees on an ADU under 750 square feet and requires proportional fees above that, tracking Gov. Code § 66311.5(c)(1) — but the state version is better than Burbank's wording in two ways worth knowing. State law exempts an ADU of 750 square feet "or less," not "under" 750, and it measures interior livable space, while Burbank measures ADU square footage exterior wall to exterior wall (§ 620.3(F)(2)). On a 2x6 wall assembly an 800 square foot Burbank ADU can be at or under 750 square feet of interior livable space. If you are near the line, put the interior-livable-space figure on the plans and cite § 66311.5(c)(1).

Only above 500 square feet — and both the City and the school district blur this. The 750 square foot line is the local impact-fee exemption. School fees are different: under Gov. Code § 66311.5(c)(3) an ADU or Junior ADU with less than 500 square feet of interior livable space is not subject to school impact fees at all. Burbank Unified's developer fee page states that fees are charged on the entire ADU if it exceeds 750 square feet, which is the wrong threshold in your favor below 750 and worth confirming in writing. The district does not publish its adopted per-square-foot rate; contact them directly.

Not under the local rule, and the local rule goes further than state law does. BMC § 10-1-620.3(Q) provides that ADUs and Junior ADUs "shall be rented for terms longer than 90 days." The state floor is 30 days under Gov. Code §§ 66323(e) and 66333(g), so Burbank has added 60 days of its own. That extra 60 days is a local standard, and § 66323(b) bars local standards on the units state law guarantees — so on a conversion ADU, a Junior ADU or the by-right detached 800 square foot unit, 30 days is the number to raise in writing. On any other ADU the 90 days stands. Either way a vacation rental is out: the 30-day floor is mandatory statewide, not optional. If your numbers depend on 30-to-89-day tenancies, which is a live market in Burbank given the studios, get the City's position in writing before you build.

No. Owner-occupancy may not be required for an ADU under Gov. Code § 66315. Junior ADUs are different, but the rule narrowed on January 1, 2026: under Gov. Code § 66333(b) as amended by AB 1154, owner-occupancy applies only where the Junior ADU shares sanitation facilities with the main house. Give it its own bathroom and the requirement does not apply. A deed restriction is still recorded under § 66333(c) covering separate sale and unit size. Note separately that if you use the +120 square foot parking bonus, that carries its own recorded deed restriction on the parking.

No. BMC § 10-1-620.3(R) states that any ADU "may be rented separate from the primary residence, but may not be sold or otherwise conveyed separate from the primary residence," and Burbank has not opted into AB 1033, the law at Gov. Code § 66342 that lets a city allow ADUs to be conveyed separately as condominiums. A handful of California cities have opted in; Burbank is not among them. The narrow qualified-nonprofit route at Gov. Code § 66341 remains available in principle but does not apply to an ordinary homeowner. A Junior ADU may never be sold separately in any city.