Bay count is the first number that determines everything else in a service department build. It sets the building footprint, the concrete work, the electrical capacity, the equipment budget, and the revenue ceiling. Get it wrong and you either build too small — capping your revenue from day one — or build too large and carry unused overhead for years. For comprehensive guidance, see our dealership service department best practices resource.
We are Auto Lift Services, and we plan the equipment layout for dealership service departments from 8-bay independent shops to 30-plus-bay mega-dealers. The question of how many bays dealership operations require is not a single number. It is a calculation based on service volume, technician count, bay type mix, and growth planning. This guide walks through the math and the practical decisions.
Start with Your Service Volume Target
The bay count calculation starts with how many repair orders (ROs) per month you need to process.
Take your monthly RO target — either your current volume if you are remodeling, or your projected volume if you are building new. Divide by 22 working days per month. That gives you ROs per day.
A general repair technician working standard flat-rate hours completes 4 to 6 ROs per day depending on the work mix. Express service techs completing oil changes and basic maintenance can process 8 to 12 ROs per day.
If your target is 1,000 ROs per month: 1,000 divided by 22 is roughly 45 ROs per day. At 5 ROs per tech per day, you need 9 general repair techs. At one tech per bay, that is 9 general repair bays. Add specialty bays — alignment, tire, express, heavy-duty — and you are at 12 to 14 total bays.
Now add 10% to 20% for growth. A dealership building a new facility should plan for where the business will be in five to seven years, not where it is today. Concrete is permanent. Adding bays after construction means expanding the building. Planning how many bays dealership facilities need should always include a growth buffer.
Bay Types: Not Every Bay Is the Same
A 12-bay service department is not 12 identical rooms with identical equipment. It is a mix of specialized work cells, each with different infrastructure requirements.
General repair bays (6 to 8 bays in a 12-bay department). These are the workhorses. Two-post lifts rated at 12,000 to 15,000 lbs — Rotary SPOA series or Challenger CL10V3. Standard 208V single-phase electrical. Minimum 12-foot clear ceiling height. Compressed air drop at each bay. These bays handle diagnostic work, brake jobs, suspension, drivetrain, engine work, and general maintenance.
Alignment bay (1 to 2 bays). Requires a lift designed specifically for alignment — a Challenger 4-post alignment lift or a Rotary scissor alignment lift. The Hunter alignment system mounts on or around the lift and requires dedicated electrical and data connections. The bay needs additional floor space for the alignment targets and camera system. Ceiling height requirement is 14 to 16 feet for overhead camera configurations. (See also: dealership alignment bay.)
A single alignment bay with a Hunter Quick Check system at the service drive generates approximately $158,000 per year in alignment revenue. High-volume dealers run two alignment bays to eliminate the bottleneck.
Tire and wheel bay (1 to 2 bays). Dedicated bays with Hunter or Rotary leverless tire changers and Hunter road force balancers. These bays need floor space for the tire machine, the balancer, and tire staging. A drive-on or scissor lift works best for tire service because it positions all four wheels at working height simultaneously.
Express service bays (1 to 2 bays). Drive-on lifts or pit-style bays designed for quick lube and basic maintenance. Separate entrance and exit lanes. Fluid evacuation systems. These bays run at high volume — 35 to 40 vehicles per day — and require a layout that minimizes vehicle movement time.
Heavy-duty bay (0 to 1 bays). If the dealership services trucks, commercial vehicles, or anything over 10,000 lbs, at least one bay needs a heavy-duty lift rated at 30,000 lbs or higher — Challenger heavy-duty or PKS platforms. This bay needs 18 to 20 feet of clear ceiling height, reinforced concrete, and higher electrical capacity.
Scaling Examples: 8 to 30+ Bays
Here is how bay count breaks down at different scales.
8-bay independent shop or small dealership. Five general repair bays, one alignment bay, one tire bay, one express bay. This is the minimum viable service department for a dealership that takes its fixed operations seriously. Revenue capacity: approximately $2.4 to $4.3 million per year.
12-bay standard dealership. Seven general repair bays, one alignment bay, one tire bay, two express bays, one flex bay (general repair or heavy-duty depending on the market). This is the most common configuration we build. Revenue capacity: approximately $3.6 to $6.5 million per year.
20-bay high-volume dealership. Twelve general repair bays, two alignment bays, two tire bays, three express bays, one heavy-duty bay. This configuration typically serves dealer groups or high-volume single-point franchises processing 2,000 or more ROs per month. Revenue capacity: approximately $6 to $10.8 million per year.
30-plus-bay mega-dealer or multi-franchise campus. These facilities are essentially small factories. Dedicated bays for every service type, multiple alignment bays, a separate express service building or wing, collision center bays with paint booths, ADAS calibration bays, and EV service bays. The equipment package alone runs $500,000 to over $1 million. (See also: EV dealership requirements.)
The question of how many bays dealership operations need at this scale is driven by throughput modeling, not simple RO math. At 30 bays, scheduling efficiency, parts logistics, and technician flow patterns matter as much as raw bay count.
Infrastructure Requirements by Bay Type
Each bay type has specific requirements that must be in the construction plans before the slab is poured.
Ceiling height. General repair bays need a minimum of 12 feet clear. Alignment bays need 14 to 16 feet. Heavy-duty bays need 18 to 20 feet. Paint booth bays need the height specified by the booth manufacturer — USI booths typically require 14 to 16 feet plus ductwork space above. Building the service department at a uniform 16-foot clear height accommodates all bay types except heavy-duty, which should be positioned at the end of the building where higher eave height is easiest to achieve.
Concrete. Every lift bay needs a minimum 4-inch slab at 3,000 to 3,500 PSI. Anchor bolt locations must be set before the pour. Inground lifts need excavated pits with reinforced concrete, waterproofing, and drainage — these must be designed by a structural engineer and coordinated with the building foundation plan.
Electrical. General repair bays need 208V single-phase for the lift. Alignment bays need additional circuits for the alignment system. Express bays need circuits for fluid systems. EV service bays need 480V three-phase — and that electrical infrastructure should be planned even if you are not equipping EV bays today, because running 480V after construction is 5 to 10 times more expensive than including it in the original electrical plan.
Compressed air. Every bay needs a compressed air drop. The main line routing, drop locations, and compressor sizing all depend on the total bay count. A 12-bay department needs 60 to 80 CFM at 150 PSI. Scale linearly from there.
Inground Lifts: Fit More Bays in Less Space
When you are trying to maximize how many bays dealership floor plans can accommodate, the lift type makes a measurable difference.
Two-post lifts require clear floor space on both sides of the vehicle for the lift columns and the arm swing path. Inground lifts sit flush with the floor — no columns, no arm swing path, no overhead obstructions.
According to Rotary engineering data, 13 inground lifts fit in the same floor space as 12 two-post lifts. That is an 8.3% increase in bay count without expanding the building footprint.
On a $3 million construction project, adding one bay by expanding the building costs $100,000 to $200,000 in additional construction. Adding one bay by switching from two-post to inground lifts costs the price differential of the lift — a fraction of the building expansion. For dealers who are constrained on lot size or building footprint, inground lifts are the most cost-effective way to increase bay count.
Inground lifts also improve the working environment. No floor-level tripping hazards. Better vehicle access for wheel and undercar work. And they look cleaner — which matters for dealerships with open-concept service departments where customers can see the bays.
Bay Count Determines Revenue Capacity
The financial case for bay count planning is straightforward. Each bay in a dealership service department generates $25,000 to $45,000 per month in revenue depending on the work type, labor rate, and utilization.
At the low end: one bay generating $25,000 per month is $300,000 per year.
At the high end: one bay generating $45,000 per month is $540,000 per year.
The difference between a 12-bay and a 13-bay service department is $300,000 to $540,000 per year in revenue capacity — every year, for the life of the building. Over a 20-year building lifespan, that one additional bay represents $6 to $10.8 million in cumulative revenue capacity.
That is why the bay count decision during construction is the highest-leverage decision in the entire project. An extra bay costs $50,000 to $100,000 to add during construction (equipment, concrete, electrical, and proportional building cost). It costs $150,000 to $300,000 to add after construction. And it generates $300,000 to $540,000 per year either way.
Plan for more bays than you think you need today. The incremental cost during construction is trivial compared to the revenue capacity you are building for the next two decades.
How We Help Plan Bay Count and Layout
We work with dealership owners, fixed ops directors, and GC partners to plan how many bays dealership service departments need based on current volume, growth targets, OEM requirements, and budget.
We provide the equipment specifications for every bay type — lift models, electrical requirements, concrete specs, ceiling height, compressed air — so the architect and GC can design the building around the equipment that will go in it. Not the other way around.
Our GC partners — our partner construction companies — build the facility. We equip it. And we warranty everything — the building and the equipment — for a minimum of two years.
If you are planning a new service department or expanding an existing one, the bay count decision is the first one to make and the most important one to get right. Contact us and we will walk through the volume math, the bay type mix, the equipment options, and the infrastructure requirements for your specific project.
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Josiah Ragsdale
Founder, Automotive Lift Services
Josiah has been installing, repairing, and inspecting automotive lifts since he was 18 years old. He founded Automotive Lift Services in 2019 after years of seeing lifts installed wrong, never inspected, and putting technicians at risk. His team now services all 50 states from their Iowa headquarters. Read more
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