Building an ADU in Manhattan Beach. Rules, costs, timeline.
What MBMC Chapter 10.74 (Ord. 25-0004) actually allows, how the three permit pathways (Building Permit Only, ADU Permit, Coastal Zone) affect your project, and what an all-in build costs on a Manhattan Beach lot in 2026.
What you can build — at a glance
Max ADU size
1,000 sqft (local ADU Permit, 2BR+) · up to 1,200 sqft (state-law pathway)
Detached height
16 ft default (MBMC § 10.74.050(A)(1)) · up to 26 ft above-garage (MB-specific, MBMC § 10.74.050(A)(1)(b))
Attached height
Up to 25 ft (matches two-story primary, MB ADU Handout Table 2)
Side & rear setbacks
4 ft
Units per SFR lot
Up to 3: conversion ADU + JADU + new detached ≤800 sqft (Gov. Code § 66323; HCD Handbook). MBMC defaults to 1 ADU + 1 JADU — state law preempts.
Parking required
None on most lots (MBMC § 10.74.050(E) state-law exemptions)
Permit timeline
60 days · ministerial review, no hearing
AB 1033 separate sale
No — Manhattan Beach has not opted in. Sale separate from primary not permitted.
DetachedUp to 1,200 sqft (state pathway) · 16 ft local default
Above-garageUp to 26 ft — MB-specific (rare 2-story path)
AttachedUp to 25 ft · matches 2-story primary
Junior ADUUp to 500 sqft inside primary dwelling
ConversionExisting accessory structure to ADU
Per MBMC Chapter 10.74 (Ord. 25-0004, effective May 1, 2025) and Gov. Code §§ 66310–66342. Units-per-lot figure reflects the state-law stack confirmed by the HCD ADU Handbook (March 2026). Full citations in the sections below.
Most LA-area cities have two ADU rulebooks — California
state law and a local ordinance — and prospects have to
navigate both. Manhattan Beach has three. The local rulebook
is Manhattan Beach Municipal Code Chapter 10.74, codified
through Ord. 25-0004 (adopted April 1, 2025; effective May 1,
2025). The state rulebook is California Government Code
§§ 66310–66342. Layered on top is the
California Coastal Zone overlay, which the City of Manhattan
Beach administers under its certified Local Coastal Program
— and which the City’s published ADU Handout
explicitly notes triggers state ADU law in place of the local
chapter.
Knowing which rulebook applies to your specific lot is the
first decision in any Manhattan Beach ADU project. We walk
through the three permit pathways in the next section. Here
are the sources behind every regulatory claim on this page:
Local ordinance. Manhattan Beach Municipal
Code Chapter 10.74 (“Accessory Dwelling Units”),
codified through Ord. 25-0004, effective May 1, 2025. The
chapter contains the city’s definitions, the three
permit pathways at MBMC § 10.74.040, the local
development standards at § 10.74.050, JADU standards
at § 10.74.060, fee rules at § 10.74.070, and
legalization rules for pre-2020 unpermitted ADUs at
§ 10.74.080.
City guidance. City of Manhattan Beach
Community Development Department “ADU
Handout,” February 2026. The handout summarizes
Chapter 10.74 in three regulatory tables (Building Permit
Only standards, ADU Permit standards, and standards
applicable to all permits) and is the city’s plain-English
interpretation of the codified rules. The handout is also the
source for the explicit Coastal Zone treatment quoted above.
State law. California Government Code
§§ 66310–66342. The full ADU statute,
including amendments from SB 543, AB 1154 (effective Jan 1,
2026), AB 1033, AB 2533, and SB 1211. State law is the
operative rulebook in the Coastal Zone and under the
Building Permit Only pathway at MBMC § 10.74.040(A).
HCD commentary. California Department of
Housing and Community Development ADU Handbook and
enforcement letters. HCD has authority to review local ADU
ordinances for state-law compliance (Gov. Code §
66316); its handbook is the operative interpretive guidance
for ambiguities in the statute.
Where state law and the local chapter ever conflict, state law
governs (Gov. Code § 66316). The 2025 Ord. 25-0004
amendments brought Chapter 10.74 substantially into alignment
with current state law, but a few residual local provisions
— notably the JADU owner-occupancy language at MBMC
§ 10.74.060(F) — are now preempted by 2026
state-law amendments. We flag those preemptions where relevant.
Three permit pathways under MBMC § 10.74.040
MBMC § 10.74.040 sets out three distinct permit pathways
for an ADU or JADU. Which pathway applies to your project
determines which rulebook governs size, setbacks, height,
design, and timeline. Most Manhattan Beach prospects don’t
realize they have a choice; the right pathway often unlocks a
larger or simpler project than the default local rules would
allow.
Pathway 1: Coastal Zone — state ADU law applies directly
If your property is in the California Coastal Zone —
generally everything west of Sepulveda Boulevard, including
the Sand Section, Hill Section, El Porto, and most of the
Tree Section — the City of Manhattan Beach ADU Handout
is explicit: “projects proposed in the Coastal Zone are
only subject to State ADU requirements.” The local
MBMC § 10.74.050 development standards do not apply.
What does apply: Gov. Code §§ 66310–66342
(the full state ADU statute), plus a Coastal Development
Permit (CDP) reviewed concurrently with the building permit.
This is the most common pathway for Manhattan Beach ADUs, and
for many properties it’s also the most permissive
— state law allows a detached ADU up to 1,200 sqft (for
2+ bedrooms) at the state-floor 16 ft height with 4 ft side
and rear setbacks, regardless of what the local zoning
district would otherwise require. The CDP review adds two to
four months and roughly $5,000 to $15,000 in soft costs, but
it does not change what you can build.
Pathway 2: Building Permit Only under Gov. Code § 66323
MBMC § 10.74.040(A) implements the statewide-exempt ADU
pathway established by Gov. Code § 66323. An applicant
may seek building permit approval alone — without an
MBMC § 10.74.040(B) ADU Permit — for any project
that satisfies the § 66323 criteria. Those criteria
include: an attached or detached ADU within an existing or
proposed primary dwelling or accessory structure, an ADU not
exceeding 800 sqft with 4 ft setbacks and 16 ft height, and
up to one statewide-exempt ADU and one JADU per single-family
lot. ADUs permitted under § 10.74.040(A) are exempt from
the local development standards at § 10.74.050 entirely
(per MBMC § 10.74.050(B)(2)(d)(i)) and don’t count
toward the property’s maximum buildable floor area.
For an East Manhattan Beach property outside the Coastal
Zone, the Building Permit Only pathway is often the simplest
route to a permitted ADU at the state-floor envelope. The
tradeoff: the 800 sqft / 16 ft size and height constraints
are absolute under this pathway. If you want a larger ADU,
you’ll need to use pathway 3.
Pathway 3: MBMC § 10.74.040(B) Local ADU Permit
The third pathway is the local ADU Permit at MBMC §
10.74.040(B). This is the route for ADUs that don’t
qualify under pathway 2 (typically because they exceed 800
sqft or 16 ft) and aren’t in the Coastal Zone. The
local ADU Permit is ministerial — no public hearing,
no design review, no city-council vote — and is
subject to the 60-day state-law review clock at Gov. Code
§ 66317. But it carries additional local design rules:
City of Manhattan Beach ADU Handout Table 2 caps studio and
1-bedroom ADUs at 850 sqft and 2-bedroom ADUs at 1,000 sqft,
requires alley-side driveway access if the lot abuts an
alley, and imposes translucent-glazing rules for any
second-story openings on non-alley lots within 12 ft of a
rear or 10 ft of a side property line (MBMC §
10.74.050(D)(4)).
Pathway 3 applies primarily to East Manhattan Beach lots
outside the Coastal Zone where the homeowner wants a larger
or taller ADU than the § 66323 envelope allows. For
most Sand Section, Hill Section, and Tree Section
properties, pathway 1 (Coastal Zone) supersedes pathway 3
entirely.
Which pathway applies to your lot?
The Backyard Review is built to answer this question before
you commit to anything. We screen-share to your specific
address, overlay the Coastal Zone boundary, check the
underlying zoning district, and identify which of the three
pathways gives you the best combination of size, height,
and timeline. That review is part of every Signature Home
proposal — no pathway decision is made until your lot
is on the table.
What you can build in Manhattan Beach
On a single-family lot in Manhattan Beach you may build up to
two units total in any combination of ADU plus JADU —
but only one of them may be a detached ADU (MBMC §
10.74.050(B)(1)(a)). On a multi-family lot, the state-law
allowances at Gov. Code § 66323(a)(3) and (4) apply
(up to eight detached ADUs at an existing multi-family
dwelling under specific conditions). The rules below cover
the most common case: a single-family detached or attached
ADU under pathway 1 (Coastal Zone, state law) or pathway 3
(local ADU Permit). Pathway 2 (§ 66323 Building Permit
Only) follows state law exclusively.
Size limits
Under the local ADU Permit pathway (MBMC § 10.74.040(B)),
the City of Manhattan Beach ADU Handout Table 2 caps studio
and 1-bedroom ADUs at 850 sqft and 2-bedroom ADUs at 1,000
sqft. Under the Coastal Zone overlay and the § 66323
pathway, the higher state-law caps at Gov. Code §
66321(c)(1) apply — up to 1,200 sqft for 2+ bedroom
ADUs and 850 sqft for studio/1BR ADUs. An attached ADU may
not exceed 50% of the primary dwelling’s buildable
floor area (MBMC § 10.74.050(B)(2)(a)(i)) regardless of
pathway. The minimum permitted size for any ADU is 220 sqft
per MBMC § 10.74.050 (consistent with the state
efficiency-unit standard at Cal. Health & Safety Code
§ 17958.1). JADUs are 150 to 500 sqft (MBMC §
10.74.060(A) and Gov. Code § 66333).
Critical state-law floor: MBMC § 10.74.050(B)(2)(d)(ii)
codifies the Gov. Code § 66321(b)(2) protection that
no local rule — setbacks, lot coverage, open space,
buildable floor area, percent-based caps — may
prevent construction of an 800-sqft ADU at 16 feet with
4-foot side and rear yard setbacks. This is the
consequential protection on tight Tree Section and East
MB lots where the underlying zoning district’s
open-space and FAR rules would otherwise block a
buildable detached ADU. (On Sand Section walk-street
lots, lot size alone usually rules out detached
construction even with this protection — see the
Sub-Areas section.)
Setbacks
Side and rear setbacks are 4 feet for all new-construction
detached ADUs (MBMC § 10.74.050(B)(2)(b); matches state
floor at Gov. Code § 66314(d)(7)). The front setback
defaults to the underlying zoning district’s
requirement. No setback is required for an ADU built within
an existing structure or in the same location and dimensions
as an existing structure (MBMC §
10.74.050(B)(2)(b)). Detached ADUs must maintain a minimum
5-foot building separation from other buildings on the lot
(MBMC § 10.74.050(B)(2)(c)).
The Sunset
— 480 sqft one-bedroom at $239,000
all-inclusive. Under 750 sqft, so it qualifies for the
full Gov. Code § 66318 impact-fee exemption. Under
850 sqft, so it fits the MBMC § 10.74.040(B) local
studio/1BR cap. Under 16 ft, so it fits the detached ADU
height cap. For a Tree Section, Hill Section, or East MB
lot with enough buildable ground to accommodate a
detached Signature Home, the Sunset is the compact
entry-level 1BR fit. (Sand Section lots typically
don’t have the buildable area for any detached
ADU — see the Sub-Areas section.)
Maximum height
Detached ADUs are capped at 16 feet (MBMC §
10.74.050(A)(1)), measured from the weighted average of
local grades around the structure’s perimeter. This
is significantly more restrictive than the 22–25 ft
caps in Beverly Hills (22 ft) or Pasadena’s landmark
properties (16 ft, 1-story). The state-law floor at Gov.
Code § 66321(b)(4) also guarantees 16 ft for any
detached ADU on a single-family lot — Manhattan Beach
cannot reduce this floor.
Two exceptions worth knowing:
Above-garage detached ADU. A detached
ADU located directly above or below a detached garage
may reach 26 feet (MBMC § 10.74.050(A)(1)(b)). This
is the only path to two-story detached ADU height in
Manhattan Beach. Our nine fixed-price Signature Homes do
not include an above-garage two-story option in
Manhattan Beach — the configuration is custom-tier
work, designed and priced to the specific lot and
existing garage.
Attached ADU. Attached ADUs may reach
25 feet per City of Manhattan Beach ADU Handout Table 2,
subject to the primary dwelling’s height. For a
homeowner who is already planning a two-story remodel or
new construction of the primary dwelling, integrating an
attached ADU at 25 ft is often the cleanest path to
two-story ADU living in Manhattan Beach.
Parking
One off-street parking space per ADU is the default
requirement (MBMC § 10.74.050(E)). In practice, almost
no Manhattan Beach ADU project actually has to add parking,
because MBMC § 10.74.050(E)(1) waives the requirement
under any of five exemptions — matching the state-law
exemption framework at Gov. Code § 66323(c). The
exemptions are:
The ADU is within one-half (½) mile walking distance of public transit;
The ADU is within an architecturally and historically significant historic district;
The ADU is part of the existing primary dwelling or any existing accessory structure;
The ADU is in an area where on-street parking permits are required but not offered to ADU occupants; or
The ADU is within one block of a city-approved and dedicated car-share parking space.
Most Manhattan Beach addresses qualify under at least one
exemption. Garage-conversion ADUs get a separate guarantee:
MBMC § 10.74.050(E)(4) prohibits the city from
requiring replacement parking when an existing garage,
carport, or covered parking structure is demolished to
build the ADU or converted into the ADU. JADUs require no
parking under any circumstance per MBMC § 10.74.060(G).
The Wilshire
— 400 sqft studio at $219,000
all-inclusive. The smallest footprint in the lineup,
which matters on the tighter Tree Section and East MB
lots where the state-law protections at Gov. Code
§ 66321(b)(2) and the 800-sqft / 16-ft floor at
MBMC § 10.74.050(B)(2)(d)(ii) make a detached ADU
buildable that local zoning would otherwise block.
Owner-occupancy
Owner-occupancy is not required for a standard ADU at a
single-family or multi-family dwelling in Manhattan Beach.
MBMC § 10.74.050(A)(3)(a) requires only a recorded
covenant addressing rental terms (30+ days), no separate
sale, and ongoing maintenance — not owner-occupancy.
JADU owner-occupancy was simplified materially on January 1,
2026 by AB 1154 (codified at Gov. Code § 66333(b)).
The owner-occupancy requirement now applies only when the
JADU shares sanitation facilities (a bathroom) with the
primary dwelling. If your JADU has its own dedicated,
separate bathroom, owner-occupancy is no longer required.
If the JADU shares a bathroom with the main house, the
owner must still reside in either the remaining portion of
the single-family dwelling or in the JADU itself as their
principal place of residence. The Manhattan Beach JADU
covenant language at MBMC § 10.74.060(F) still
describes the broader pre-2026 owner-occupancy rule; state
law preempts that older local language.
Impact fees
ADUs under 750 sqft of livable interior space are exempt
from all local impact fees, including school district fees,
park-and-recreation fees, water and sewer connection fees,
and any other fee normally tied to new residential
construction (Gov. Code § 66318). This is a state-law
protection Manhattan Beach cannot override, and MBMC
§ 10.74.070(A) explicitly carves out the state-law
fee exemptions at Gov. Code §§ 66324, 66338,
and 66341. ADUs over 750 sqft are subject to impact fees
charged proportionally to the size of the ADU relative to
the primary dwelling — not at the full per-unit rate
that would apply to standalone new construction.
City building-permit fees and plan-check fees are separate
from impact fees. They apply to ADUs at any size. For a
detached new-construction ADU under 1,000 sqft, total city
permit and plan-check fees typically run
$9,000–$14,000. For Coastal Zone projects, add
$5,000–$15,000 for the Coastal Development Permit.
Those fees go to the city and are passed through at cost
in a CALI ADU contract.
Design rules — alley access and second-story glazing
Two design rules in MBMC § 10.74.050(D) are worth
flagging early. First: if your lot abuts an alley, any
new driveway access for the ADU must come through the
alley (§ 10.74.050(D)(2)). This is non-negotiable
and shapes site plans in most Tree Section and El Porto
blocks. Second: for any second-story detached ADU on a
non-alley lot, all exterior openings within 12 feet of a
rear property line or 10 feet of a side property line
must have translucent glazing — fixed, or set high
on the wall — except for the main entry
(§ 10.74.050(D)(4)). The rule protects neighbor
privacy and is enforced at plan check. Note that the
second-story rule only matters under the above-garage
26-ft configuration; standalone detached ADUs are capped
at 16 ft.
Permitting timeline
State law requires the City of Manhattan Beach to act on a
complete ADU or JADU permit application within 60 days of
submittal (Gov. Code § 66317; MBMC §
10.74.040(C)). The 60-day clock starts when the city deems
the application complete and pauses while the applicant
responds to plan-check corrections. SB 543, effective
January 1, 2026, added a separate 15-business-day
completeness determination deadline: if the city does not
issue an incomplete-application letter within 15 business
days of submittal, the application is deemed complete by
operation of law (Gov. Code § 66317(a)(2)). Together
these deadlines cap the realistic in-house permit timeline
at roughly 90–120 days for a clean application.
Coastal Zone projects add the CDP review on top of (but
concurrent with) the building permit clock.
ADUs in the Manhattan Beach Coastal Zone
Most of Manhattan Beach — everything west of Sepulveda
Boulevard, plus a small east-of-Sepulveda strip in El Porto
— lies inside the California Coastal Zone, the
regulatory boundary established by the California Coastal
Act of 1976 (Pub. Resources Code § 30000 et seq.).
The Coastal Zone covers the Sand Section, the Hill Section,
El Porto, and the western edge of the Tree Section.
For an ADU project, the Coastal Zone designation has two
practical consequences:
State ADU law applies, not the local chapter.
The City of Manhattan Beach ADU Handout puts this
plainly: “projects proposed in the Coastal Zone are
only subject to State ADU requirements.” The local
MBMC § 10.74.040(B) ADU Permit standards (the 850
sqft cap for studios/1BRs, the 1,000 sqft cap for 2BRs,
the alley-driveway rule, the translucent-glazing rule)
do not apply. The operative rulebook is Gov. Code
§§ 66310–66342 — meaning up to
1,200 sqft for 2+ bedrooms, the 16 ft / 4 ft / 800 sqft
state floor, and the full state-law parking and
owner-occupancy framework.
A Coastal Development Permit is required in
addition to the building permit. The CDP is
reviewed concurrent with the building permit by the
City’s Community Development Department (delegated
authority under the city’s certified Local Coastal
Program) and, for some categories of project, requires
referral to the California Coastal Commission. For a
typical Sand Section attached ADU or garage conversion,
the CDP review is a documentation exercise — site
plan, elevations, drainage, view-corridor analysis
— and does not change what you can build. For a
Hill Section detached ADU on a sloped lot with grading
or view-impact issues,
the CDP review is materially more involved.
The CDP review typically adds two to four months to the
overall permit timeline and roughly $5,000 to $15,000 in
soft costs (Coastal Commission processing fees, additional
plan-set work, view-corridor and drainage analysis). The
building permit’s 60-day state-mandated review clock
(Gov. Code § 66317) runs in parallel.
One nuance worth knowing: Coastal Zone projects under MBMC
§ 10.74.040(A) (the § 66323 Building Permit Only
pathway) follow a slightly different fee and parking
framework — per City of Manhattan Beach ADU Handout
Table 3, the “no additional or replacement
parking” rule has a Coastal Zone exception, meaning
the parking-exemption analysis defers to the Coastal Act
and the underlying CDP review rather than purely to Gov.
Code § 66323(c). We work through the parking analysis
as part of every Coastal Zone Backyard Review.
Sand Section, Hill Section, Tree Section, East MB
Manhattan Beach’s four named sub-areas have noticeably
different lot dimensions, slope conditions, and ADU
economics. Knowing which sub-area your property is in
shapes which Signature Home fits, what the permit pathway
looks like, and what kind of rental return is realistic.
Sand Section (walk-streets and beach blocks)
The Sand Section runs roughly from Manhattan Beach Boulevard
north and south of Marine Avenue, extending east to roughly
Highland Avenue. Lots here are very small — many
parcels are 30′ by 90′ (2,700 sqft) on the
famous walk-streets, with the primary dwelling already
occupying most of the buildable envelope after setbacks
and lot-coverage rules.
The practical consequence for ADUs is that a detached
Signature Home is usually not viable on a Sand Section lot.
The lot size, setbacks, and the existing footprint of the
primary residence leave too little ground available for a
new free-standing structure that still meets the 5-foot
building separation at MBMC § 10.74.050(B)(2)(c). The
state-law 800 sqft / 16 ft / 4 ft floor at Gov. Code
§ 66321(b)(2) protects against most percent-based
and open-space rules, but it does not create buildable
land that physically doesn’t exist.
What does work on a Sand Section lot: an attached
ADU built as an addition to the primary dwelling
(up to 50% of the primary’s buildable floor area
per MBMC § 10.74.050(B)(2)(a)(i), at the 25-ft
attached-ADU height in the Coastal Zone), or an
ADU conversion created entirely within
an existing garage, accessory structure, or portion of
the primary dwelling under Gov. Code § 66323(a)(1).
Conversion ADUs are exempt from setbacks (no setback is
required for an ADU built within an existing structure
per MBMC § 10.74.050(B)(2)(b)) and qualify for the
full garage-conversion parking exemption at MBMC
§ 10.74.050(E)(4). Almost all Sand Section properties
are in the Coastal Zone, so the Coastal Zone overlay
(pathway 1) applies — state ADU law plus a Coastal
Development Permit. This is custom-tier work, designed
and priced to the specific existing structure rather than
drawn from the fixed-price Signature Home lineup; we work
through the attached vs. conversion decision in the
Backyard Review.
Hill Section (large premium lots with view considerations)
The Hill Section sits east of Highland Avenue and north of
Manhattan Beach Boulevard. It extends up to the Country
Club and is bounded on the east by Sepulveda. Lots are
larger here — typically 4,500–7,500 sqft. Many
sit on the city’s namesake slope with partial Pacific
or downtown LA views. All Hill Section properties are inside
the Coastal Zone (pathway 1). The larger lots open up the
full state-law detached ADU envelope at up to 1,200 sqft
and 16 ft. On view-eligible lots, view-corridor analysis
becomes a meaningful part of the CDP review. The 16-ft
height cap is the binding constraint for two-story
ambitions. The cleanest two-story path is often an attached
ADU at 25 ft, integrated into a two-story primary dwelling
(per City of MB ADU Handout Table 2). Best Signature Home
fits: the Lincoln
(1,000 sqft 3BR/2BA, $389,000) and
the Melrose (800 sqft
2BR/2BA, $329,000).
Tree Section (family-oriented mid-block bungalows)
The Tree Section runs east of Sepulveda. Its western edge
is still inside the Coastal Zone. It covers most of the
family-oriented, tree-lined SFR blocks between Pacific
Avenue and Aviation Boulevard. Lot sizes are mid-range
(typically 5,000–6,500 sqft) and many lots have
alley access. That triggers the alley-driveway rule at
MBMC § 10.74.050(D)(2) for any new ADU parking. The
dominant aesthetic is older Craftsman and 1940s–1950s
bungalow stock. New ADU construction that respects that
aesthetic adds more to property value than modernist
designs that fight the block. Best Signature Home fits:
the Lincoln
(Craftsman feel, 1,000 sqft 3BR), the Melrose
(800 sqft 2BR with a traditional gable variant), and
the Laurel Canyon
(660 sqft 2BR/1BA, $289,000, traditional gable).
East Manhattan Beach (across Sepulveda)
East Manhattan Beach refers to the residential blocks east
of Sepulveda Boulevard, including the area around Mira
Costa High School and the Manhattan Heights neighborhood.
These properties are outside the Coastal Zone
— the only Manhattan Beach sub-area where pathway 1
(Coastal Zone) does not apply. East MB ADU projects
therefore choose between pathway 2 (§ 66323 Building
Permit Only, capped at 800 sqft / 16 ft) and pathway 3
(local ADU Permit, with the 850/1,000 sqft and design
rules at MBMC § 10.74.050). Lots are typically
5,500–7,000 sqft with mid-century housing stock.
Pathway 3 (local ADU Permit) opens the door to slightly
larger 2BR builds at the local 1,000 sqft cap; for owners
wanting more than that, the only path is an attached ADU
at 25 ft or an above-garage detached ADU at 26 ft (both
custom-tier work). Best Signature Home fits: the Melrose
(800 sqft 2BR/2BA) and the Lincoln
(1,000 sqft 3BR/2BA, at the upper local cap).
How California state law backs South Bay homeowners
Manhattan Beach’s local ordinance is among the
better-drafted ADU chapters in the South Bay — Ord.
25-0004 brought it substantially into alignment with
current state law — but the state-law backstops at
Gov. Code §§ 66310–66342 still matter in
several specific situations. The most consequential
protections every Manhattan Beach prospect should know:
The 800-sqft / 16-ft / 4-ft floor. No
local rule — setbacks, lot coverage, open space,
FAR, percent-based caps — may prevent construction
of an 800-sqft ADU at 16 feet with 4 ft side and rear
setbacks (Gov. Code § 66321(b)(2); codified
locally at MBMC § 10.74.050(B)(2)(d)(ii)). This is
the single most consequential protection on tight Sand
Section walk-street lots.
Ministerial-only review. ADU permits
are ministerial under all three pathways at MBMC §
10.74.040 — no design review, no neighborhood
compatibility review, no city-council vote (Gov. Code
§ 66317(a)(1)). If your plans meet the objective
standards, the city must approve them within 60 days.
State-law height floor. Gov. Code
§ 66321(b)(4) guarantees a minimum 16-foot height
for any detached ADU on a single-family lot. Manhattan
Beach’s 16-ft local cap matches the state floor
exactly — meaning the floor is the ceiling for
standalone detached ADUs here, but it cannot go lower.
Parking exemption near transit. No
off-street parking may be required for an ADU within
one-half mile walking distance of public transit (Gov.
Code § 66323(c)(1); codified at MBMC §
10.74.050(E)(1)(a)).
Garage-conversion parking exemption.
When an ADU is created by converting an existing garage,
carport, or covered parking structure, the city cannot
require replacement parking (Gov. Code §
66323(c)(2); codified at MBMC § 10.74.050(E)(4)).
Impact-fee exemption under 750 sqft.
ADUs under 750 sqft are exempt from all local impact
fees (Gov. Code § 66318; MBMC § 10.74.070(A)
carves out the state-law exemptions explicitly).
Pre-2020 legalization. Unpermitted ADUs
constructed before January 1, 2020 must be permitted
under MBMC § 10.74.080 (implementing Gov. Code
§ 66331) — the city cannot deny a
legalization permit on the grounds that the ADU
violates current standards, unless the violation
implicates Cal. Health & Safety Code § 17920.3
substandard-building criteria.
AB 1033 separate-sale opt-in. Gov.
Code § 66342 (added by AB 1033) lets cities allow
separate sale of an ADU as a condominium. Manhattan
Beach has not adopted an opt-in ordinance as of the
latest review of MBMC Chapter 10.74. The MBMC §
10.74.050(A)(3)(a)(ii) covenant language preserves the
future option (“unless otherwise required by state
law”) but does not currently grant separate-sale
rights.
HOA preemption. Homeowner association
covenants that prohibit or unreasonably restrict ADUs
are unenforceable (Gov. Code § 66342 broader
protections). If a Manhattan Beach HOA tries to block
your ADU, the state-law preemption controls.
The end-to-end permit process and timeline
ADU permits in Manhattan Beach are issued by the Community
Development Department, Planning and Building Divisions
(1400 Highland Avenue). The end-to-end process for a clean
detached new-construction project on a standard
single-family lot takes roughly 5–7 months from
contract signing to issued building permit (longer in the
Coastal Zone), broken down as:
Weeks 1–4: Design and engineering. Site survey, architectural plan customization for your specific lot, structural engineering, Title 24 energy compliance documentation, plan-set assembly.
Weeks 5–6: Pathway analysis and pre-submittal package. Confirm which of the three MBMC § 10.74.040 pathways applies (Coastal Zone, § 66323 Building Permit Only, or local ADU Permit), assemble the pathway-specific submittal package, prepare the ADU covenant for recording.
Week 7: Submittal. Electronic submittal through the City of Manhattan Beach plan-check portal. State-law 15-business-day completeness determination clock starts (Gov. Code § 66317(a)(2)). For Coastal Zone projects, CDP application filed concurrent with building permit.
Weeks 8–15: Plan check. City plan-check review (60-day clock under Gov. Code § 66317), plus corrections cycle and resubmittal. Typical Manhattan Beach ADU project sees one to two correction cycles.
Weeks 12–20: Coastal Development Permit (Coastal Zone projects only). CDP review runs concurrent with the building permit and typically lands 2–4 months from submittal. View-corridor and drainage analysis on Hill Section properties may extend this.
Weeks 16–22: Permit issuance. Pay city permit and plan-check fees ($9,000–$14,000 typical, plus $5,000–$15,000 CDP for Coastal Zone), pick up the approved permits.
We handle all permit processing, Coastal Development Permit
coordination, plan-check correspondence, and agency
clearances as part of every Signature Home project. The
covenant required at MBMC § 10.74.050(A)(3) or §
10.74.060(F) is drafted to the City Attorney’s
approved form and recorded with LA County prior to final
building inspection.
Signature Homes that fit Manhattan Beach lots
Three picks from the nine-model lineup for Manhattan Beach detached-ADU work — sloped Hill Section view lots, family-oriented Tree Section bungalow blocks, and East MB mid-century parcels. All three picks are single-story to fit the MBMC § 10.74.050(A)(1) 16-ft detached ADU cap. Sand Section properties are typically too tight for a detached Signature Home; the path there is an attached ADU or a garage conversion, both of which are custom-tier work designed to the existing structure.
Single-story and attached projects only — none of the two-story portfolio builds fit Manhattan Beach's 16-ft detached cap. The work below maps cleanly onto what MB prospects typically need: a Craftsman-aesthetic single-story detached ADU for the Tree Section, a seamless attached garage conversion (a real Manhattan Beach project) for the Sand Section walk-street typology, a Spanish-style garage conversion for a coastal-aesthetic lot, and a turnkey rental ADU for the investor-owner segment.
The all-in cost of a Signature Home ADU in Manhattan Beach
is the same as in every other LA-area city we serve:
pricing does not vary by neighborhood. Our nine
architect-designed Signature Homes range from
$219,000 (Wilshire 400 sqft studio)
to $459,000 (Culver 1,200 sqft
three-bedroom two-story). The price includes architectural
design, structural engineering, Title 24 energy
compliance, all permit processing and plan-check
correspondence through to issued permit, all construction
labor and materials, interior finishes, cabinetry,
countertops, flooring, fixtures, appliances, and utility
connections for water, power, sewer, and gas.
What is not included in the Signature Home all-inclusive
price: City of Manhattan Beach permit and plan-check fees
(paid directly to the city, passed through at cost),
Coastal Development Permit fees for Coastal Zone projects,
and any site-specific work outside the standard package
(unusual grading on Hill Section slopes, retaining walls,
long utility runs, view-corridor analysis on Coastal Zone
properties with view-eligibility, drainage modifications
adjacent to walk-streets). We identify and price all
site-specific work in the proposal before contract signing
— the number on the contract is the number you pay.
The Lincoln
— 1,000 sqft three-bedroom two-bath single-story,
$389,000 all-inclusive. The largest
single-story Signature Home and the strongest aesthetic
match for Manhattan Beach’s family-oriented Tree
Section bungalow blocks and the older single-family
streets of the Hill Section. At 1,000 sqft, it sits at
the upper boundary of the local ADU Permit pathway 3
(City of MB ADU Handout Table 2 caps 2BR at 1,000 sqft;
Lincoln is 3BR so its 1,000 sqft fits the more
permissive state-law cap under pathway 1 / Coastal
Zone).
For a typical Manhattan Beach project, total cost to the
homeowner is the Signature Home all-inclusive price plus
$9,000–$14,000 in City of Manhattan Beach permit
and plan-check fees. Coastal Zone projects add
$5,000–$15,000 in CDP soft costs. The all-in number
for a typical Coastal Zone Manhattan Beach Signature Home
project lands at $233K–$488K depending on which
model you choose. Run your specific numbers on our
ADU ROI calculator —
the tool takes your lot, your model, your expected rent,
and your financing assumptions and returns a year-by-year
cashflow plus payback projection.
Why Manhattan Beach is a strong ADU market
Manhattan Beach is one of the highest-value ADU markets in
LA County on a per-square-foot basis. Single-family home
values in 2026 typically run $3M–$8M+ depending on
sub-area, and the supply of new single-family inventory
has remained tightly constrained for years — the
city has effectively no buildable greenfield land. An ADU
on an existing Manhattan Beach lot captures a meaningful
slice of that property-value scarcity premium without
triggering any of the entitlement risk associated with
subdivision or larger redevelopment.
Rental returns are strong but require careful attention to
which pathway and which sub-area you’re working in.
One-bedroom ADUs in the Sand Section command long-term
(30+ day) rents of $3,200–$4,200 per month;
two-bedroom Tree Section ADUs command $4,000–$5,500
per month; Hill Section ADUs with partial views or
high-end finishes can clear $5,000+. Short-term rentals
under 30 days are heavily restricted in Manhattan Beach
— the city’s STR ordinance permits STRs only in
specific zones with a registration requirement, and most
residential ADU zones do not qualify. Plan around
long-term rental as the base case.
On the property-value side, a well-designed 1,000 sqft ADU
on a Manhattan Beach Tree Section or Hill Section lot
typically adds $500K–$900K to property value
— a meaningful multiple of the all-in construction
cost. For owners considering long-term hold,
multigenerational use, or rental income, the math is
consistently favorable.
Manhattan Beach ADU questions, answered
The questions Manhattan Beach homeowners actually ask
before they start — with citations to MBMC Chapter
10.74 (Ord. 25-0004), the City of Manhattan Beach ADU
Handout, and Gov. Code §§ 66310–66342.
Does Manhattan Beach have its own ADU ordinance?
Yes. Manhattan Beach Municipal Code Chapter 10.74
governs ADUs and JADUs at the local level. The chapter
was most recently amended by Ord. 25-0004 (adopted
April 1, 2025; effective May 1, 2025) to align with
current California state law. MBMC § 10.74.040
sets out three distinct permit pathways: (A) a
Building Permit Only path under Gov. Code §
66323 for statewide-exempt small ADUs, (B) a local
ADU Permit path under MBMC § 10.74.040(B) with
additional city-specific design standards, and the
Coastal Zone overlay (state ADU law applies directly
per the City of Manhattan Beach ADU Handout, plus a
Coastal Development Permit). Most ADU projects in
Manhattan Beach proceed under pathway (A) or the
Coastal Zone overlay.
How big can my ADU be in Manhattan Beach?
It depends on the permit pathway. Under MBMC §
10.74.040(B) (the local ADU Permit pathway), the City
of Manhattan Beach ADU Handout Table 2 caps studio and
1-bedroom ADUs at 850 sqft and 2-bedroom ADUs at
1,000 sqft. Under the § 66323 Building Permit
Only pathway and the Coastal Zone overlay, state law
applies — Gov. Code § 66321 allows a
detached ADU up to 1,200 sqft (2+ bedrooms) or 850
sqft (studio/1BR). All pathways respect the
state-law floor at MBMC § 10.74.050(B)(2)(d)(ii):
no local rule can prevent an 800-sqft ADU at 16 ft
with 4 ft side and rear setbacks. JADUs are capped
at 500 sqft per MBMC § 10.74.060(A) and Gov.
Code § 66333.
Can I build a two-story detached ADU in Manhattan Beach?
Not as a standalone detached ADU. MBMC §
10.74.050(A)(1) caps detached ADUs at 16 feet,
measured from the weighted average of local grades
around the structure’s perimeter. The only way
to get a two-story configuration is under MBMC
§ 10.74.050(A)(1)(b), which permits a detached
ADU located directly above or below a detached
garage to reach 26 feet. That above-garage
configuration is custom-tier work — our nine
fixed-price Signature Homes do not include an
above-garage two-story option in Manhattan Beach.
For two-story living on a Manhattan Beach lot, the
more common path is an attached ADU integrated into
an existing or proposed two-story primary residence;
attached ADUs may reach 25 feet per the City of
Manhattan Beach ADU Handout Table 2.
Do I need to add a parking space for my ADU in Manhattan Beach?
Probably not. MBMC § 10.74.050(E) requires one
off-street parking space per ADU but waives the
requirement under any of five exemptions, mirroring
Gov. Code § 66323(c): the ADU is within
one-half mile walking distance of public transit,
within an architecturally and historically significant
historic district, within the existing primary
dwelling or accessory structure, in an area where
on-street parking permits are required but not
offered to ADU occupants, or within one block of a
city-approved car-share parking space. Most
Manhattan Beach addresses qualify under at least
one exemption. Garage-conversion ADUs are also
exempt — MBMC § 10.74.050(E)(4)
prohibits the city from requiring replacement
parking when an existing garage is converted to an
ADU. JADUs require no parking under any
circumstance per MBMC § 10.74.060(G).
Does Manhattan Beach require owner-occupancy for an ADU?
No, not for a standard ADU. MBMC §
10.74.050(A)(3)(a) requires only a recorded
covenant addressing rental terms (30+ days), no
separate sale, and maintenance — not
owner-occupancy. For a JADU, the rule changed on
January 1, 2026: AB 1154 amended Gov. Code §
66333(b) so owner-occupancy is now required only
when the JADU shares sanitation facilities (a
bathroom) with the primary dwelling. If your JADU
has its own dedicated, separate bathroom,
owner-occupancy is no longer required. The
Manhattan Beach JADU covenant language at MBMC
§ 10.74.060(F) still describes the broader
pre-2026 owner-occupancy requirement; state law
preempts that older local language.
What happens if my Manhattan Beach property is in the Coastal Zone?
Most of Manhattan Beach west of Sepulveda Boulevard
is in the California Coastal Zone — including
the Sand Section, the Hill Section, El Porto, and
most of the Tree Section. The City of Manhattan
Beach ADU Handout is explicit on the regulatory
treatment: “projects proposed in the Coastal
Zone are only subject to State ADU requirements.”
That means the local MBMC § 10.74.040(B) ADU
Permit standards do not apply — only state
law under Gov. Code §§ 66310–66342.
The catch is that a Coastal Development Permit
(CDP) is still required in addition to the building
permit. The CDP review runs concurrent with the
building permit but typically adds two to four
months and roughly $5,000 to $15,000 in soft costs
to the project.
What are the height limits for ADUs in Manhattan Beach?
Detached ADUs are capped at 16 feet per MBMC
§ 10.74.050(A)(1), measured from the weighted
average of local grades around the
structure’s perimeter. This is significantly
more restrictive than Beverly Hills, Burbank, or
Culver City. The two exceptions: (1) a detached ADU
located directly above or below a detached garage
may reach 26 feet per MBMC §
10.74.050(A)(1)(b) — this is the only path
to two-story detached ADU height in Manhattan
Beach; and (2) attached ADUs may reach 25 feet per
the City of Manhattan Beach ADU Handout Table 2,
subject to the primary dwelling’s height.
State law (Gov. Code § 66321(b)(4)) also
guarantees a minimum 16-foot height for any
detached ADU on a single-family lot —
Manhattan Beach cannot reduce this floor.
Can I sell my Manhattan Beach ADU separately from the main house?
Not currently. AB 1033 (Chaptered 2023; codified
at Gov. Code § 66342) gave California cities
the option to allow separate sale of an ADU as a
condominium, but the right only activates once a
city adopts an opt-in ordinance. Manhattan Beach
has not adopted an AB 1033 opt-in ordinance as of
the latest review of MBMC Chapter 10.74 (codified
through Ord. 25-0004, effective May 1, 2025). The
standard ADU covenant required at MBMC §
10.74.050(A)(3)(a)(ii) still prohibits separate
sale “unless otherwise required by state
law” — that residual language
preserves AB 1033 rights if Manhattan Beach
adopts an opt-in ordinance in the future, but
until then separate sale is not available.
Fixed price in writingGuaranteed timelineCoastal Zone & CDP handled
Ready to build your ADU in Manhattan Beach?
We’ll check your lot, confirm whether you’re in
the Coastal Zone (most of MB is), identify which of the
three MBMC § 10.74.040 pathways gives you the best
combination of size and timeline, walk you through which
Signature Home fits your block, and give you a fixed
number — before you commit to anything. 15 minutes.
