Add A Rentable, Code-Ready Backyard Home — Starting at $110,695, Installed.

Turnkey accessory dwelling units engineered by BOSS Homes in Montebello, California. Code-compliant from day one. From intro call to move-in in 4 to 9 months.

240–1,200 sq ft floor plans
4–9 Months contract to move-in
50% faster than stick-built
IBC + CBC code-compliant
ENTRY-LEVEL MODEL — STUDIO CORE
$110,695
Typical installed price including civil work and assembly. Subject to location and site review.
Comparable CA turnkey ADUs Run: $229K-$439K
  • 10' × 24', 240 sq ft studio
  • California-manufactured panelized system
  • Factory-integrated MEP — no on-site framing
  • Meets International + California Building Codes
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Built on a credentialed manufacturer

BOSS Homes builds the panelized system used by California cities.

Durasheds offers BOSS Homes ADUs to homeowners — Built On Site Systems — a California prefab housing manufacturer with a state contract, named municipal projects, and three generations of building-product engineering behind it.

CA

California DGS Statewide Contract

Awarded by the Department of General Services for emergency cabin housing across the state.

CBC

International + California Building Code compliant

Engineered, tested, and explicitly permittable under IBC and CBC. Stamped engineering drawings provided for every order.

CA

Offices in Montebello, California

Short freight, in-state code expertise.

Built Project

Cherry Avenue Interim Housing

San José, CA · 2025

Built Project

Dignity Village

Modesto, CA

Built Project

33 Gough

San Francisco, CA

Built Project

City of Baldwin Park

Los Angeles County, CA

BOSS Homes ADU installed in California
The BOSS Technology

Panelized walls and roof. Built in the factory, with MEP already integrated.

The BOSS system combines the speed of prefab with the flexibility of site-built — without cranes, volumetric modules, or special transport permits.

01

Factory-built panels

Cold-rolled galvanized steel framework, lightweight PIR insulated core, gypsum board interior and fiber-cement exterior — all factory-installed.

02

Integrated MEP

Framing, insulation, sheathing, and rough mechanical, electrical, and plumbing — all built into the panel before it ships. On-site work is connecting, not constructing.

03

Palletized delivery

Panels arrive on standard pallets. No cranes, no road closures, no volumetric-module permits. No oversized transport needed.

Traditional

Stick-built

Framing, insulation, drywall, MEP — all done on-site, in sequence, weather-dependent. 12–18 months in California.

Modular

Volumetric box

Built complete in a factory, then shipped on an oversized load. Crane required to set. Limited by transport permits and lot access.

BOSS Homes

Panelized + integrated MEP

Best of both: factory precision, no crane, no oversized transport. Panels lock together on site. 4–9 months total.

The 8-Model ADU Lineup

From a 240 sq ft studio to a 1,200 sq ft three-bedroom — all turnkey installed.

Every BOSS model is California-engineered, CBC-compliant, and priced as a typical installed project including civil work and assembly.

Studio Core ADU
Studio

Studio Core

10' × 24' · 240 sq ft · Studio
$110,695
Typical installed price
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Most Popular
Studio

Studio Plus

12' × 28' · 340 sq ft · Studio
$122,595
Typical installed price
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One Bed Core ADU
One Bedroom

One Bed Core

16' × 24' · 400 sq ft · 1 BR
$142,495
Typical installed price
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One Bed Plus ADU
One Bedroom

One Bed Plus

16' × 32' · 500 sq ft · 1 BR
$178,395
Typical installed price
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Two Bed Basic ADU
Two Bedroom

Two Bed Basic

26' × 30' · 800 sq ft · 2 BR
$228,395
Typical installed price
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Two Bed Core ADU
Two Bedroom

Two Bed Core

20' × 40' · 800 sq ft · 2 BR
$233,095
Typical installed price
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Two Bed Plus ADU
Two Bedroom

Two Bed Plus

24' × 34' · 800 sq ft · 2 BR
$241,195
Typical installed price
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Three Bed Core ADU
Three Bedroom

Three Bed Core

30' × 40' · 1,200 sq ft · 3 BR
$368,895
Typical installed price
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How a BOSS ADU Happens

Six Steps From Intro Call to Move-In.

A single accountable team handles design, permitting support, factory production, delivery, and assembly.

Step 01

Intro Call or Office Meeting

30 minutes with our team to talk through your lot, goals, budget, and timeline. Visit our Montebello Office in person if you can.

~1 Week
Step 02

Design Call + Feasibility Study

We review your jurisdiction's ADU rules, lot conditions, and zoning to confirm what's buildable. Model selection and configurator session.

2–3 Weeks
Step 03

Confirm Design + Permit Set

Final plan locked. Place the order. Stamped permit set prepared for your city's submittal.

2 Weeks
Step 04

Permits + Foundation

Submit to your city. LA permits run 60-90 days under SB 543. Foundation work runs in parallel.

1–3 Months
Step 05

Factory Manufacturing + Site Prep

Your panels are produced in Montebello while utilities are trenched and the foundation is set. The two phases run in parallel.

4–6 Months
Step 06

Delivery + Assembly + Finish

Panels arrive on pallets. Structural raising in days. Interior finish, MEP terminations, inspections, certificate of occupancy.

1–2 Months
A Realistic California Timeline

4 to 9 months, contract to move-in.

Honest numbers, not brochure numbers. A stick-built ADU in California takes 12 to 18 months. Volumetric-modular runs 8 to 12 months but still needs cranes, oversized transport, and broader lot access. Panelized BOSS, with permits and production running in parallel, brings it down to 4 to 9 months.

Design + Permit Set
Feasibility, model selection, stamped drawings prepared.
3–6 Weeks
Permitting
60-90 days for custom designs under SB 543. 3-6 months in coastal zones. Pre-approved plan paths available in some jurisdictions
1–3 Months
Factory Production
Runs in parallel with permits. Reflects current category-wide manufacturer queue.
4–6 Months
Site Prep + Foundation
Slab or piers, utility trenching, rough connections. Runs in parallel with manufacturing.
3–6 Weeks
Assembly + Interior finish
Panel raising in days. Interior finish, MEP, inspections in weeks.
4–8 Weeks
Total: Contract to Move-In
Roughly half the time of stick-built. Survives any contractor conversation.
4–9 Months
The Investment Math

A BOSS ADU should pay you back in under a decade.

ADUs typically generate $1,500–$3,500 per month in California rental income and lift property value 20–35%. Pair the BOSS installed price with realistic rent for your zip and the math gets interesting fast.

$1,500–$3,500 Typical monthly rent (CA market)
Up to $40,000 CalHFA ADU grant (when program funding is open)
20-35% Property value uplift
Waived Impact fees on ADUs under 750 sq ft

Sample ROI — Two Bed Basic (800 sf)

California, Los Angeles County, market rent
BOSS Installed Price $228,395
Site Upgrades & Utility Extensions $22,000
Permits, Inspections, Fees $8,000
Total Project Cost $258,395
Estimated Monthly Rent (2-BR LA) $2,850
Annual Cash Flow (pre-tax) $34,200
Estimated Payback Period 7.5 years
Get my custom ROI report

A Comparable 2-Bedroom ADU Installed in California.

Typical California installed turnkey prices for a 2-bedroom ADU. Real apples-to-apples on the core question — what does a 2-BR turnkey cost?
BOSS Abodu Villa Homes Samara
Installed price (2-BR sqft) $228,395 ~$425,000 ~$320,000 ~$439,000
Contract to move-in 4–9 months 8–10 months 6–9 months 8–12 months
Construction system Panelized + integrated MEP Modular box Panelized / ReadyBuilt Modular box
CA Building Code compliant Yes (IBC + CBC) Yes Yes Yes
CA state contract / municipal projects Yes — CA DGS No No No
Crane / oversize transport required No Yes No Yes
Sources: bosshomes.com (BOSS installed pricing); public pricing pages and 2026 market analysis (Abodu, Villa Homes, Samara). Move-in timelines reflect typical real-world delivered projects in California (permitting + factory queue + on-site work). They may run faster or slower than published brochure quotes depending on jurisdiction, plan customization, and current factory backlog. BOSS's quotes are confirmed at the design call.
Permits & Laws

Every California city has its own rules. We have a guide for each one.

California's 2026 ADU reforms (AB 462, AB 1154, SB 543) tightened permit timelines and expanded by-right ADU rights statewide. Here's the short version, with deeper guides for each jurisdiction.

Los Angeles

21–30 day permits on pre-approved plans (LADBS Standard Plan Program). City of LA leads California in annual ADU permits. Impact fee exemption on ADUs under 750 sf.

Read the LA guide →

San Diego

3–6 month timelines in coastal zones (cut in half by AB 462). 15-day completeness deadline under SB 543.

Read the San Diego guide →

San Francisco

By-right ADUs up to 1,200 sf detached. Coastal review streamlined. State 60-day approval rule applies.

Read the SF guide →

Sacramento

60-day permit window under state law. Up to $40K CalHFA ADU grant when program funding is open. No parking requirements. Impact fee waiver on ADUs under 750 sf.

Read the Sacramento guide →

San José

Active ADU expansion zones. Cherry Avenue community delivered with BOSS panels. Pre-approved plans available.

Read the San José guide →

Long Beach

State-mandated 60-day permit window applies. Long Beach has standardized ADU plans in development for faster approval paths. State by-right rules (1,200 sf detached, 4-ft setbacks) apply on most R1 lots.

Read the Long Beach guide →

Oakland

One ADU + one JADU allowed by-right on most single-family lots. Multifamily properties may qualify for additional units under SB 1211. Pre-approved plan library expanding.

Read the Oakland guide →

State of California

AB 462, AB 1154, SB 543 explained. 60-day mandatory decision. CalHFA grant program (up to $40K when funded).

Read the California overview
Frequently Asked

The questions every California ADU buyer has.

Yes. BOSS systems are engineered to comply with both International Building Code (IBC) and California Building Code (CBC) requirements. We also provide jurisdiction-specific permit support and pre-approved plan options in many California cities.
Typical installed pricing includes factory-built panels, structural assembly, standard finishes, project coordination, and core construction labor. Site-specific work such as grading, utility upgrades, and permit fees may vary by property.
Most BOSS ADU projects are completed in approximately 4–9 months, depending on city permitting timelines, utility coordination, and customization level. Factory production and site work happen in parallel to reduce delays.
BOSS uses factory-built panelized construction with integrated MEP systems. Unlike modular boxes, panels ship on standard pallets without cranes or oversized transport permits. Compared to stick-built, assembly is dramatically faster and more precise.
Many California homeowners use HELOCs, construction loans, refinance products, or ADU-specific lending programs. Some buyers may also qualify for grants or fee waivers depending on city and income requirements.
Yes. Buyers can customize layouts, finishes, doors, windows, rooflines, exterior materials, and interior options while keeping the efficiency of the standardized BOSS system.
Get Started

Book An Intro Call. Get a Custom ADU Quote In 48 Hours.

Tell us about your project. We'll come back with a model recommendation, an all-in installed cost, a permit roadmap for your jurisdiction, and a realistic 4–9 month schedule.

What You Get With Your Intro Call

  • BOSS Model Recommendation Based On Your Lot and Goals
  • All-In Installed Project Estimate, No Surprise Change Orders
  • Permit Roadmap For Your Specific California Jurisdiction
  • Realistic 4–9 Month Schedule With Key Milestones
  • Rental Income & ROI Projection For Your Zip
  • Financing Options Including HELOC + CalHFA Grant Eligibility
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