Garage Conversion Contractor - Design, Permits and Build Under One Contract

Trusted Garage Conversion Contractor Nationwide

Most garages were never built to be lived in. They have a concrete slab with no insulation, one wall outlet, maybe a bare bulb overhead, and a roll-up door that leaks air all winter. Turning that space into a comfortable, code-compliant room takes more than framing and drywall. It takes a contractor who understands foundations, drainage, ventilation, electrical load, and the building rules in your specific area. That’s the work our crews do every day, and we’ve done it since 2010 under The Kingswell Guarantee: a written price before work begins, a real arrival window, a clean job site, and a written guarantee on every project. If the work isn’t done right, we come back and make it right within 365 days. Call (254) 602-5618 and a live person answers, any hour, any day.

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Key takeaways:

• Most garage conversions cost between $80,000 and $150,000 nationally, depending on finish level and site conditions.
• Every project starts with a written price, not an estimate that shifts once the walls are open.
• Permits are not optional. We handle drawings, submissions, inspections, and corrections.
• The 365-Day Done Right Promise is in writing on every single build. If it’s wrong, we come back.
• We work with established ADU brands and materials including Dvele, Mighty Buildings, Boxabl, and Plant Prefab.

Garage Conversion Permit

A garage conversion permit is the legal approval from your local building department to change an existing garage from vehicle storage into conditioned living space, and it is required in virtually every jurisdiction in the United States. We pull every permit for every project, handle the plan submissions and corrections, schedule the inspections, and don’t ask for final payment until the building department signs off. Permit costs vary by region, but homeowners should budget roughly $2,000 to $8,000 for permit fees, plan preparation, and related filing costs, which is separate from construction.

What the permit process covers

The permit package for a garage conversion usually addresses structural changes, insulation values, window and door egress requirements, electrical service, plumbing if a bathroom or kitchen is added, and the heating and cooling system. Each jurisdiction reviews these differently, which is why we handle the back-and-forth directly with the plan checker. Our crews have shepherded conversions through hundreds of planning and building departments across the country.

What happens without one

An unpermitted garage conversion sits on the property record as nonconforming work. When the homeowner goes to sell, refinance, appraise, or file an insurance claim, the unpermitted square footage becomes a liability that can stall the transaction or void coverage. The cost to legalize it later almost always exceeds the cost of doing it correctly the first time.

Garage Conversion to Living Space

A garage conversion to living space is the process of transforming an attached or detached garage into a heated, cooled, insulated room that meets the legal definition of habitable square footage in your area, and hiring our Garage Conversion Contractor in Los Angeles ensures it’s done right. It typically requires raising or replacing the slab, building up the exterior walls, adding a proper roof assembly, and upgrading the electrical panel to handle real living loads. A national-scale project like this usually lands between $80,000 and $150,000 depending on size, site access, and whether plumbing is added.

Fixing the slab and moisture

Most garage slabs slope toward the driveway and sit directly on grade with no vapor barrier underneath. That means water moves toward the house and moisture wicks up through the concrete all year. A proper conversion means addressing slope, adding a vapor barrier, insulating the slab, and often framing a new floor system above it. Skipping this step is the number one cause of musty, cold, failing garage rooms we get called to fix.

Walls, roof, and ceiling

Garage walls are usually 2×4 framing with no insulation and exterior siding not rated for conditioned space. The roof often has no insulation either, and the ceiling may be open to rafters. We reframe and insulate to current energy code, install continuous air barriers, and replace the garage door with a code-compliant wall assembly that matches the rest of the home. The result is a room that holds temperature like the rest of the house, not a shed with drywall.

Garage to Bedroom Conversion

Garage to bedroom conversion means turning garage square footage into a legal sleeping room, which carries specific code requirements beyond a general living space: an emergency egress window, a permanent heat source, minimum ceiling height, and a closet or designated storage in most jurisdictions. A straightforward single-bedroom conversion without a bathroom typically runs $80,000 to $120,000, while adding an ensuite bath pushes the range toward $130,000 to $150,000 or more.

Egress and safety requirements

A bedroom must have at least one operable window large enough for a firefighter in full gear to enter and for an occupant to escape. That usually means cutting a new opening in the exterior wall and installing a properly sized egress window with a rated well if the sill sits below grade. We coordinate this with the structural engineer, because cutting a large opening in a load-bearing garage wall requires a header sized for the span.

HVAC and electrical for a bedroom

A garage rarely has ductwork or enough electrical capacity for a bedroom. We extend the home’s HVAC system or install a dedicated ductless unit, and we upgrade the circuit panel when needed so the room can run lights, outlets, and a space heater or window AC without tripping breakers. Bringing a bedroom up to code also means hardwired, interconnected smoke detection that ties into the rest of the house.

Garage Conversion ADU

A garage conversion ADU is an accessory dwelling unit created from an existing garage, complete with its own entrance, kitchen, bathroom, and sleeping area, making it a fully self-contained second home on the same lot. This is the highest-ROI version of a garage project, since finished ADUs in many markets rent for $1,200 to $2,800 per month. Budget $110,000 to $150,000 for a typical one-bedroom ADU conversion, with premium finishes and prefab components from brands like Dvele or Boxabl pushing the upper end of that range.

Kitchen and bath scope

An ADU needs a functioning kitchen and a full bathroom, which means running new supply lines, waste lines, and venting from the main dwelling. That’s the single biggest cost driver in a garage conversion ADU, and the reason some homeowners choose a JADU (junior accessory dwelling unit) that shares a bathroom with the main house. We walk through both options and price them separately before any work starts.

Prefab and panelized options

We have hands-on experience with several high-end prefab and panelized ADU systems. Dvele and Mighty Buildings produce factory-built modules with near-passive-house performance, Boxabl is known for its compact folding Casita units, and Plant Prefab specializes in custom panelized construction. Matching the right system to your lot access, foundation conditions, and budget is part of the upfront conversation we have with every client.

Garage Apartment Conversion

A garage apartment conversion turns a detached garage into a rentable apartment with its own kitchen, bathroom, entrance, and often its own utility connections, separated from the main house by more than a wall. Detached structures almost always need new or upgraded water, sewer, gas, and electric service run from the street or main dwelling, which pushes typical costs to $130,000 to $180,000 or more depending on trenching distance and utility availability.

Utility runs and site work

Detached garages were rarely plumbed or wired for full-time living. Running a new sewer lateral across a 50-foot backyard can cost $8,000 to $20,000 by itself depending on soil, depth, and landscaping restoration. We price this work from the actual site plan, not from a per-square-foot guess, so the written price you see accounts for the trenching, backfill, and compaction before we begin.

Separation and privacy

A good garage apartment conversion creates true privacy between the primary residence and the new unit. That means sound isolation in shared walls, separate metering where local utilities allow, and a dedicated entrance that doesn’t route tenants through the family’s living space. We pay attention to these details from the first site walk, because a rental unit that feels like a converted garage doesn’t command market rent. One that feels like a small house does.

Brands We Service

We work directly with several leading ADU and prefab manufacturers and know their products from the factory floor specs to the final trim details. Dvele builds high-performance, factory-finished modules with integrated smart-home systems, and we handle the site preparation, utility connections, and finishing work those modules require. Mighty Buildings produces panelized units using a 3D-printed composite material, and our crews are trained on the assembly sequencing and tolerance requirements that system demands.

Boxabl produces the compact Casita unit that unfolds on site, and we’ve managed the foundation specs, crane coordination, and mechanical hookups for those units. Plant Prefab specializes in customized panelized homes built in a controlled factory environment, and we ensure the foundation and site work match the factory drawings to the eighth of an inch. Whether your project uses one of these systems or a conventional stick-built approach, we can help.

Signs You Need a Pro Right Now

• The garage floor slopes toward the house. Water moves downhill, and a garage slab pitched toward your foundation is sending runoff directly at your home’s framing every time it rains. Over years, that moisture rots sill plates and invites termites. A conversion has to correct the slope before anything else gets built on top of it.
• You can see daylight around the garage door. Gaps around the door mean the space has been unconditioned, vented, and exposed to outside air since the day it was built. That’s expected for a garage and unacceptable for living space. The door comes out, the opening gets framed and insulated, and the wall assembly gets brought up to code.
• The electrical panel maxes out when you run a space heater. A garage circuit was sized for a door opener and a work light, not a bedroom, bathroom, and kitchen. If your panel trips when you plug in basic appliances, the entire service likely needs an upgrade as part of the conversion.
• There’s a gas water heater or furnace in the garage. Combustion appliances in a space you plan to seal up and live in create real carbon monoxide and fire-safety issues. The equipment has to be relocated, enclosed with outside combustion air, or replaced with a sealed-combustion or electric unit, and this work must be permitted and inspected.
• The previous owner already half-converted it. We see a lot of garages with drywall, carpet, and a window AC that were never permitted. Those spaces often hide missing insulation, improper wiring, and no egress. A pro needs to open those walls, document what’s there, and fix it before you invest another dollar in finishes.

Our Process, Step by Step

1. 1
   Site walk and feasibility. A project lead walks the property, measures the garage, checks panel capacity, looks at foundation conditions, and talks through what you actually want the space to do. This is when we identify deal-breakers like lot-line setbacks, septic capacity, or HOA restrictions, so you know what’s possible before spending money on drawings.
2. 2
   Written scope and price. You get a line-item written price covering the full scope: demolition, foundation, framing, insulation, mechanicals, finishes, permits, and site work. That number does not change at the door. If you want to add or remove scope later, we re-price the change in writing and you approve it before the work proceeds.
3. 3
   Permits and drawings. We prepare or coordinate the architectural drawings, structural calcs, and energy calculations, submit them to your building department, and handle plan-check corrections. You don’t stand in line at the counter and you don’t chase down an inspector.
4. 4
   Construction with a defined window. The crew shows up in the arrival window we gave you, in uniform, background-checked, and working to a schedule we share with you. We protect floors through the house, contain dust, and clean the site at the end of every work day. The Kingswell Way is simple: say the price before the work, show up when we said, leave the place cleaner than we found it.
5. 5
   Inspection, walkthrough, and written guarantee. Before we call the job done, the building department does their final inspection and we do a full walkthrough with you. Every item on the punch list gets addressed. Then you receive the written 365-Day Done Right Promise, which says in plain English: if the work isn’t right, we come back and make it right, no charge, within one full year.

How Much Does Garage Conversion Contractor Cost?

Where We Work

Lodgewick ADU Builders serves homeowners across the United States through local crews that operate under The Kingswell Guarantee. Each location is independently owned and operated, but every project follows the same written-price, written-warranty, clean-job-site standard. When you call, a live person answers and connects you with a team that knows the building rules in your area. Home

Frequently Asked Questions About Garage Conversion Contractor

Schedule Your Garage Conversion Contractor Service Today

You want a real number in writing and a crew that shows up and does the job right. That’s what we deliver on every project, backed by the 365-Day Done Right Promise. Call (254) 602-5618 for a free, no-obligation estimate from a garage conversion contractor who puts every commitment on paper. A live person answers. That’s the Kingswell Guarantee.

Written by Russ Delmar, Owner at Lodgewick ADU Builders, serving homeowners nationwide since 2010.