ADU
Construction
& Remodeling
By Bartona
Builders

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bartona builders Accessory dwelling unit construction in la county

What Is an ADU and Why Build One?

An Accessory Dwelling Unit (ADU) is a secondary living space on your property. Think backyard cottage, garage conversion, or basement suite.

ADUs in Los Angeles serve multiple purposes, like: generate rental income, house multigenerational family members, offer a private guest retreat, or create a dedicated home office.

At Bartona Builders, we specialize in designing and constructing modern, code‑compliant ADUs that maximize livability and value.

Benefits of Building an ADU

Generate Passive Income

Turn unused space into a steady rental stream

Keep Family Close, Yet Independent

In‑law suites and multigenerational units foster togetherness without sacrificing privacy.

Boost Property Value & ROI

Well‑built ADUs can add 20–30% to your home’s resale value.

Affordable Alternative to Buying

Create a second living unit at a fraction of the cost of a standalone property.
What we can build

Types of Accessory dwelling units We Build and/or Remodel

detached ADU Backyard Cottages Bartona Builders

Detached ADUs (Backyard Cottages)

attached ADU Home Extensions in Los angeles Bartona Builders

Attached ADUs (Home Extensions)

Garage Conversions in Los angeles Bartona Builders

Garage Conversions

basement ADU Bartona Builders

Basement ADUs

Over garage ADU unit Bartona Builders

Over‑Garage Units

Internal conversions within existing square footage Bartona Builders

Internal Conversions within existing square footage

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bartona builders adu addition

ADU Design & Layout Features

  • Open Floor Plans
    with strategic furniture placement for space optimization
  • Kitchenettes or Full Kitchens
    tailored to unit size and use
  • Compact Bathroom Designs
    featuring corner showers and wall‑hung fixtures
  • Private Entries & Outdoor Access
    for tenant independence
  • Smart Storage Solutions
    like built-in closets and under‑stair compartments
  • Energy‑Efficient Appliances & Systems
    to lower utility costs
How we work

Our ADU Process

We value your time. So, we have simplified our process into 3 easy-to-follow steps:

Consultation & Feasibility Review

We assess your lot, zoning regulations, and goals to determine the ideal ADU type and size.

Design & Permitting

Architectural plans, engineering details, and permit applications handled seamlessly.

Construction & Completion

Licensed crews build your ADU with quality craftsmanship and clear communication at every step.

why work with us

why choose bartona builders

Transparent Pricing & Consistent Updates

Full design‑build service under one roof

Deep Expertise in ADU Zoning & Permitting

Over a century of combined home improvement experience

Licensed, insured, and dedicated to your peace of mind

Custom Layouts that comply with local regulations and suit your lifestyle

ADU Cost Breakdown

ADU TypeTypical Investment RangeKey Cost Drivers
Detached Backyard Cottage$80,000 – $180,000Foundation work, utilities hook‑ups, finishes
Attached Home Addition$70,000 – $150,000Structural tie‑ins, roofing, site access
Garage Conversion$40,000 – $100,000Garage door removal, insulation, plumbing rough‑in
Basement ADU$60,000 – $140,000Excavation (if needed), waterproofing, egress
Over‑Garage Unit$90,000 – $200,000Staircase addition, structural reinforcement

Factors influencing cost: square footage, ADU type, utility extensions, finish level, and permitting fees. Consider rental income potential or family use when evaluating investment.

Common ADU Challenges (and How We Solve Them)

We navigate local codes to maximize allowable size and placement.

Creative site planning ensures compliance without sacrificing curb appeal.

Our engineers design reliable connections and water‑management systems.

We guide you through loan programs and provide realistic project schedules.

Space‑saving features and flexible layouts make every square foot count.

Frequently asked questions (FAQs)

A secondary dwelling unit on your property—detached or attached—used for living, rental, or work.

Generally $40K–$200K depending on type, size, and finishes.

Yes—most local jurisdictions allow rental, though some restrict short‑term leases.

Absolutely. We handle all permitting and code compliance on your behalf.

Zoning dictates allowed ADU types; we perform a feasibility study upfront.

Typical timelines range from 3–6 months from design to move‑in.

Yes—converting a garage into a living unit is one of the most cost‑effective ADU options.

Many homeowners use home‑equity loans, construction loans, or cash‑out refinance programs.

Likely, yes—added square footage and assessed value may raise your tax basis.

Limits vary by jurisdiction, typically between 400–1,200 sq ft; we’ll confirm your city’s rules.

Our Los Angeles County Service Area

We serve all locations in Los Angeles County. Please contact us for more details about your specific location.