The 90-day garage conversion is real. It is not the norm, it is not guaranteed, and it is not what most contractors who promise it actually deliver — but it is achievable under a specific set of conditions that are worth understanding before you sign a contract with anyone who puts a timeline on their proposal.
The timeline promise is one of the most reliable indicators of a contractor's integrity in the ADU market. Firms that promise 90-day conversions without qualifying the conditions that make 90 days possible are either inexperienced or optimistic in ways that will cost you money and months of additional waiting. Firms that refuse to commit to any timeline at all are managing their own exposure at the expense of your planning. The firm worth hiring is the one that explains what 90 days actually requires — and tells you honestly whether your specific project meets those conditions.
Los Angeles has the most active garage conversion market in the country. California's ADU reform legislation has made garage conversions one of the most financially compelling capital improvements available to single-family and multifamily property owners — adding rental income, adding property value, and in some cases creating a separately saleable asset under AB 1033. The market for garage conversion contractors has expanded rapidly to meet that demand, and it has expanded faster than the quality controls that would keep it honest.
The result is a market full of timeline promises that don't survive contact with LADBS plan check, LADWP coordination, and the field conditions of the existing garage structure. Here is what a realistic garage conversion timeline actually looks like, what makes a 90-day conversion possible, and what warning signs tell you that the contractor's timeline is a sales tool rather than an operational commitment.
What a Garage Conversion Actually Involves — The Scope That Determines the Timeline
Before discussing timelines, it is necessary to establish what a garage conversion actually encompasses — because the scope of work is the primary determinant of the timeline, and contractors who promise short timelines frequently do so by understating the scope.
A garage conversion is not a renovation. It is a change of occupancy — the transformation of a structure designed and permitted as a non-habitable accessory structure into a permitted, inspected, code-compliant dwelling unit. That transformation involves structural, architectural, electrical, plumbing, mechanical, and energy compliance work — each of which has its own design requirements, permit requirements, and inspection milestones.
The specific scope elements that every garage conversion must address:
Structural assessment and upgrade — The existing garage structure was designed for garage loads, not residential occupancy loads. The framing must be assessed for its capacity to support the residential live loads, the new roofing or flooring loads if a loft or second story is being added, and the lateral seismic loads that apply to a habitable structure. In most cases, the structural assessment reveals conditions that require some level of upgrade — additional hold-down hardware, upgraded connections, shear wall additions, or foundation bolting.
Insulation and thermal envelope — A garage is not thermally conditioned. The walls, ceiling, and floor of the conversion must be insulated to meet California Title 24 energy efficiency requirements for residential occupancy — which are substantially more demanding than the requirements for a garage.
Electrical service and panel — Most garages have minimal electrical service — a few circuits for lighting and perhaps a 240-volt circuit for a garage door opener or workshop equipment. A residential ADU requires a full electrical system: circuits for kitchen appliances, bathroom exhaust, HVAC, lighting, and general receptacles, typically served by a dedicated subpanel or an upgraded service entrance. In many cases, the main panel serving the primary residence must also be upgraded to support the additional ADU load.
Plumbing — A garage conversion with a kitchen and bathroom requires new plumbing — supply lines, waste lines, and in most cases a connection to the existing sewer lateral or the addition of new lateral capacity. Plumbing work in a slab-on-grade garage frequently requires saw-cutting the concrete slab to install below-grade waste lines — a significant construction operation that is often underestimated in both cost and schedule.
HVAC — A habitable ADU requires a heating system, and in most of Los Angeles a cooling system as well. A mini-split system — the most common HVAC solution for garage conversions — requires an electrical circuit, refrigerant line sets, and a condensing unit on the exterior. The HVAC specification affects the electrical panel sizing and the Title 24 energy compliance calculations.
Exterior improvements — The garage conversion typically requires modifications to the exterior that reflect its new residential use: a new entry door with residential hardware, windows that meet the egress and natural light requirements for habitable rooms, and in some cases exterior finish modifications to match the primary residence or meet HOA requirements.
Title 24 energy compliance — The California Energy Code requires a complete energy compliance calculation for any new habitable space. The calculation covers the thermal envelope, the HVAC system efficiency, the lighting, and in some cases the water heating system. The Title 24 compliance documentation must be prepared by a qualified energy consultant and submitted with the permit application.
This is the complete scope of a garage conversion — not a simplified version of it, not the scope that the cheapest bid covers, but the scope that a permitted, inspected, code-compliant ADU requires. Any contractor who proposes a scope that omits any of these elements is either planning unpermitted work or planning to discover the missing scope as a change order after you've committed to the project.
The Permit Timeline — The Variable Nobody Controls But Everyone Underestimates
The single largest source of garage conversion timeline variance is the permit process — specifically, the LADBS plan check timeline and the correction cycle that follows first submission.
A garage conversion permit application requires architectural drawings, structural calculations, Title 24 energy compliance documentation, a site plan, and in many cases electrical and plumbing plans. These documents must be coordinated — the structural calculations must match the architectural dimensions, the Title 24 calculations must match the HVAC specification shown in the architectural plans, and the electrical plans must match the panel schedule shown in the structural drawings.
When this documentation package is submitted to LADBS, a plan check engineer reviews it for code compliance and coordination. The review timeline — from submission to first correction letter or approval — depends on LADBS's current workload, the project type, and the submission track selected by the applicant. Standard plan check timelines at LADBS have ranged from three weeks to three months in recent years, depending on workload cycles. Over-the-counter review — available for certain project types that meet the criteria for simplified review — can reduce the initial review timeline significantly.
The correction cycle adds additional time to the permit timeline. A first submission that generates a 20-item correction letter — which is common on discoordinated submittals — requires a response that addresses each correction, a resubmission, and a second review cycle before the permit is issued. Each review cycle at LADBS is two to four weeks. Two correction cycles add four to eight weeks to the permit timeline beyond the initial review.
The total permit timeline for a garage conversion — from first submission to permit issuance — ranges from six weeks for a well-prepared, over-the-counter eligible submittal to five months for a complex project with multiple correction cycles. This range is real, it is determined primarily by the quality of the submittal package, and it is the variable that most dramatically affects the project timeline.
Contractors who promise 90-day conversions without addressing the permit timeline are either planning to submit to over-the-counter review — which requires specific project conditions that not every garage conversion meets — or they are not telling you that the 90 days starts when the permit is issued, not when you sign the contract.
The LADWP Timeline — The Permit Problem That Isn't LADBS
Garage conversions that require electrical service upgrades — which is most garage conversions, because the existing garage electrical service is inadequate for residential occupancy — involve a LADWP coordination step that operates on an entirely separate timeline from the LADBS permit.
When the ADU's electrical load requires an upgrade to the service entrance serving the property — a new meter base, a larger service panel, or in some cases a transformer upgrade on LADWP's side of the meter — the owner must file a LADWP service application and wait for LADWP's engineering review and field work before the new service can be energized.
LADWP's service upgrade timeline is independent of LADBS's permit timeline. It cannot be accelerated by the contractor. It operates on LADWP's own scheduling, which reflects their crew availability, transformer procurement lead times, and the volume of service upgrade requests in the queue. In the current market — where ADU construction has driven a surge of service upgrade applications across the LA service territory — LADWP timelines for service upgrades have ranged from six weeks to six months.
A contractor who initiates LADWP coordination concurrent with LADBS plan check submission — on the first day of the project, not after the permit is issued — can minimize the impact of LADWP's timeline on the overall project schedule. A contractor who initiates LADWP coordination after the LADBS permit is issued — the most common approach in the market — makes LADWP's timeline the critical path item after construction is otherwise complete. The ADU is built. The permit is issued. The construction is done. And the project sits, waiting for LADWP to energize a service that nobody thought to request until everything else was finished.
The Field Condition Variable — What the Existing Garage Contains
Every garage conversion begins with an existing structure — and existing structures contain conditions that are not visible in the pre-contract assessment and that materially affect the conversion scope and timeline.
The most common field condition surprises in garage conversions:
Slab on grade conditions — Most garages have a slab-on-grade concrete floor. The condition of that slab — its thickness, its reinforcement, its bearing on the existing soil, and its relationship to the surrounding grade and drainage — is not visible without investigation. Slabs that are inadequately thick for habitable floor loading, slabs that have been cracked by differential settlement, and slabs that are below the outside grade in a way that creates drainage problems are common conditions that affect the conversion scope. A slab that requires replacement or significant repair adds both cost and schedule to the project.
Foundation conditions — The existing garage foundation — typically a perimeter stem wall with a continuous footing — was designed for garage loads and may not be adequate for the residential occupancy loads and seismic requirements that the conversion imposes. Foundation assessment requires investigation that may not be possible without excavation at the footing — and foundation conditions that require upgrade add scope that was not in the original proposal.
Existing electrical conditions — The existing garage wiring is frequently a mix of different vintages, different installation standards, and different levels of code compliance. Older aluminum branch circuit wiring, improperly spliced circuits, and undersized conductors are common conditions that require remediation as part of the conversion — and that are not visible until the walls are opened.
Roof structure conditions — The garage roof structure — particularly in older detached garages — may have deteriorated at the connection points, accumulated moisture damage at the eave ends, or been modified without permits in ways that affect its structural adequacy. The conversion scope for a garage with a compromised roof structure includes roof repair or replacement that was not in the original estimate.
Contractors who budget for field condition contingencies — who include an allowance in the fixed-price bid for the discovery work that characterizes every garage conversion — are pricing the project honestly. Contractors who bid without contingency and recover the field condition costs as change orders are producing the timeline and budget surprises that make garage conversion a frustrating experience for many LA property owners.
What 90 Days Actually Requires — The Conditions That Make It Possible
A 90-day garage conversion — measured from permit issuance to certificate of occupancy — is achievable when the following conditions are present simultaneously:
A complete, coordinated permit package that achieves over-the-counter approval or short plan check cycle. This requires architectural drawings, structural calculations, and Title 24 documentation that are prepared by an integrated team — not by an architect who hands off to an outside structural engineer who hands off to an outside energy consultant. The coordination quality that produces a clean first submission is the product of in-house engineering — the same team responsible for design and structural analysis, working from the same model.
LADWP service coordination initiated at project inception. If the service upgrade is in LADWP's queue from day one of the project — not from permit issuance — LADWP's timeline runs concurrently with construction rather than sequentially after it. A service upgrade that takes eight weeks is an eight-week delay if initiated after construction; it is zero additional delay if initiated at the start of design.
A garage structure in adequate condition for conversion without major structural remediation. The 90-day timeline assumes that the existing structure is fundamentally sound — that the foundation is adequate, the slab can be used as the habitable floor, the roof structure is in acceptable condition, and the existing framing does not require significant replacement. A garage that requires foundation work, slab replacement, or significant structural remediation is not a 90-day project — and an honest assessment of the existing structure before the contract is signed is the only way to know which category your garage falls into.
An in-house construction crew with current scheduling availability. Construction timeline is a function of crew availability as much as project complexity. A contractor with a six-week backlog at permit issuance cannot deliver a 90-day construction timeline regardless of how efficiently they work once mobilized.
When all four conditions are present, 90 days from permit issuance to certificate of occupancy is a realistic target. When any one of them is absent, the timeline extends — and the contractor who promised 90 days without assessing these conditions is managing expectations at your expense.
The Realistic Timeline — What Most Garage Conversions Actually Take
For the majority of Los Angeles garage conversion projects — projects that don't have exceptional pre-conditions but also don't have significant structural complications — the realistic timeline from project initiation to certificate of occupancy is five to nine months. Here is how that breaks down:
Design and permit preparation: four to six weeks from project kickoff to first LADBS submission, assuming an integrated design-build team with in-house engineering.
LADBS plan check and permit issuance: six to fourteen weeks, depending on submission track and correction cycles. Projects that achieve over-the-counter review are at the six-week end. Standard plan check with one correction cycle is at the ten-to-twelve week end.
Construction: six to ten weeks for a straightforward garage conversion without major structural complications — framing modifications, insulation, drywall, electrical, plumbing, HVAC, and finishes.
Final inspection and certificate of occupancy: one to two weeks after construction completion.
Total from project initiation to certificate of occupancy: five to nine months for a typical project. Projects with LADWP service upgrade requirements that weren't initiated concurrently with design add one to three months. Projects with significant structural complications add additional time proportional to the remediation scope.
This is the honest timeline. It is not the marketing timeline. It is the timeline that property owners who have done their first conversion with a contractor who promised less report as their actual experience — and the timeline that property owners who have done their first conversion with SKS report as what they were told upfront.
How SKS Approaches Garage Conversion Timelines
SKS Construction does not promise 90-day garage conversions as a marketing claim. We assess your specific garage, evaluate the conditions that affect the timeline, initiate LADWP coordination on day one, and provide a realistic timeline that reflects the actual project conditions — not the best-case scenario that sells contracts.
Our in-house licensed structural engineer conducts the pre-contract assessment of the existing garage structure — evaluating foundation conditions, slab adequacy, framing condition, and the structural upgrade scope that the conversion will require. This assessment is the basis for the fixed-price proposal and the timeline commitment. We know what we're building before we price it and before we schedule it.
Our in-house architectural and engineering team prepares coordinated permit submissions — the structural calculations match the architectural drawings, the Title 24 compliance reflects the specified HVAC system, the electrical plans match the panel schedule. Our LADBS submissions have a short correction cycle history because the coordination is done before submission, not in response to LADBS corrections.
We initiate LADWP service coordination at project inception — not at permit issuance. We know from 39 years of LA construction experience that LADWP's timeline is the variable that most commonly extends garage conversion projects beyond their planned completion, and we manage it accordingly.
Fixed-price bids. No subject-to-change clauses. Direct owner access to Shahab and Sam Shaolian. 39 years. 3,000-plus completed projects. 80% repeat clients.
We will tell you how long your conversion will actually take. And then we will take that long — not longer.
Get a FREE Garage Conversion Assessment and Realistic Timeline
SKS Construction offers FREE garage conversion feasibility assessments for property owners across Los Angeles County. Our in-house engineer will evaluate your existing garage structure, assess the permit conditions that apply to your specific project, identify any LADWP service upgrade requirements, and provide a fixed-price proposal with a realistic timeline — based on your actual project conditions, not a best-case scenario.
If you've been quoted 90 days by another contractor, bring that quote to the conversation. We'll tell you whether 90 days is realistic for your specific project — and if it isn't, we'll tell you what is.
Call (818) 855-1181 or email info@sksconstruction.com to schedule your FREE garage conversion assessment today.
info@sksconstruction.comCA CSLB License #AB720390(818) 855-1181