Autolift Garage Build-Out Dimensions: A Dealer Deep-Dive

A dealership service manager in Cedar Falls called us last summer with a straightforward problem: three new bays going into a shop expansion, all three needed to be up and running by the fall service rush, and the general contractor did not understand lift specifications. This article is the technical deep-dive we sent back — real dimensions, real sequencing, and real tolerances for an autolift garage build in a dealership environment. If you are planning a new bay or a full build-out, everything in here comes from the last twelve dealer installs we have finished across northern and central Iowa. The numbers are not rounded, and the sequence is not optional if you want the bay to work for 20 years.

Bay Dimensions for a Proper Autolift Garage

A proper dealership bay is 14 feet wide by 28 feet deep at minimum. The 14-foot width gives the tech a comfortable door swing on both sides of a full-size pickup once it is up in the air on a two-post. Anything under 12 feet 6 inches and the driver’s door hits the column on an F-250 crew cab, which is a daily annoyance and a paint repair waiting to happen. The 28-foot depth accommodates the vehicle length, a tool cart at the front, a fluid cart at the rear, and enough space for a tech to walk around without shuffling equipment. Cedar Falls dealers running full-size trucks routinely spec 15 by 30, which is more comfortable but not strictly necessary.

The column-to-column spacing on a two-post is 12 feet 2 inches for a standard-width Rotary SPO12, and 11 feet 0 inches for the low-profile version. A four-post at 14K needs 11 feet 8 inches between the outside faces of the runways, and a wheels-free bridge jack adds about 6 inches of vertical accommodation that the ceiling must account for. Every autolift garage build we spec starts with a scale drawing of the bay, not a napkin sketch. The GC gets that drawing before the slab is poured, which saves everyone a redo later.

Ceiling Height: The Number You Cannot Cheat

A 10,000-pound Rotary two-post needs a 12-foot clear ceiling. A 12,000-pound needs 12 feet 2 inches. A 14,000-pound four-post with drive-on ramps needs 12 feet 4 inches, and if you want a wheels-free bridge jack raised on top of that you are looking at 13 feet minimum practical. If the ceiling is any lower, you have to step down in capacity or step down to a low-ceiling asymmetric model that limits vehicle class. There is no workaround. We measure ceiling height before the quote goes out on every single job, because a bad ceiling number kills a build faster than anything else.

Ceiling height also affects duct routing and lighting placement. HVAC ducts have to run above the fully extended lift, which means they get shoved up against the roof deck and lose insulation R-value. Overhead lights have to clear the raised vehicle by at least 8 inches, which usually means recessed cans placed carefully on either side of the lift envelope rather than a single fixture centered over the bay. Every lift bay we plan for a dealer includes a lighting layout because dim bays cost the shop measurable dollars in tech productivity, and dealership techs are fast to complain about lighting.

Sequencing the Build: Concrete Before Anything Else

The single most important sequencing decision on a dealership build-out is the concrete pour. Slab thickness has to be 6 inches at 3,500 PSI for the 12K and 14K lifts we typically spec into a dealer environment, and the mix has to cure for 28 days before we anchor into it. If the GC pours in July and wants lifts installed in August, the answer is no. That 28-day cure is not optional and it is not an engineering suggestion — it is what the anchor manufacturer’s pullout spec is based on. Anchoring into green concrete is how you get a column that walks under load six months later.

We give the GC a pour date target 30 days before the desired install date. That gives the concrete 28 days plus a two-day buffer for weather or delivery slippage. In a Cedar Falls dealer install last year, the GC pushed the pour a week and we still hit the install date because we had front-loaded the schedule. Every autolift garage we install into a new-construction bay follows the same rule: slab first, cure 28 days, then equipment. Nothing else in the sequence is worth arguing about.

Utilities Rough-In Before the Autolift Garage Equipment Arrives

Compressed air, electrical, and waste-oil plumbing all get roughed in before the slab is poured. A two-post lift needs a 220-volt single-phase or 208/230 three-phase circuit run to a disconnect within 6 feet of the column base. The circuit is typically 30 amp for the 10K lifts and 40 amp for the 12K and larger. Wire gauge is 10 AWG for the 30-amp circuits and 8 AWG for the 40-amp, run in EMT conduit stubbed up through the slab at the column location. Doing it after the pour means saw-cutting concrete, which nobody wants.

Air lines get roughed in the same way. A one-half-inch line from the compressor to a stub-up at the lift is standard for pneumatic tool feed. Waste oil drain lines from a floor grate or catch basin under the lift envelope run to a below-grade tank that gets pumped quarterly. All three of these utilities have to be planned before the concrete crew shows up. Every dealer build we sequence includes a utility drawing that the GC hands to the electrician and plumber. That drawing is what turns a chaotic install into a boring one, which is what you want.

Placement Math: Column-to-Column and Drive-Path

Column placement inside the bay matters more than most GCs realize. A two-post has to be set so that the vehicle centerline is exactly equidistant from both columns and so that the arms sweep clear of the bay walls at all positions. For a bay position measured from the roll-up door, we usually set the columns 14 feet 6 inches back from the door to center the vehicle in the bay with room for a tool cart in front. Drive-path clearance from door to column has to be at least 12 feet so the tech can drive in without a spotter or a fender scrape.

For a four-post, the runways run parallel to the length of the bay with 4 feet minimum clearance to the side wall on one side (for the walkway) and 3 feet on the other. The front runway edge sits 8 feet back from the roll-up door to accommodate the drive-on ramp angle and vehicle length. In a lift plan for a Cedar Falls dealer running a mix of sedans and trucks, we usually spec the four-post to accommodate the longest vehicle the shop expects to service — often an F-350 crew-cab long-bed at 22 feet, which sets the runway length.

Real Dimensions From Cedar Falls Dealer Installs

From our last three Cedar Falls dealer jobs, here are the actual finished dimensions. Bay A: 14 feet wide, 30 feet deep, 12 feet 4 inch ceiling, Rotary SPO12 12K two-post centered 15 feet from the roll-up door. Bay B: 16 feet wide, 32 feet deep, 13 feet ceiling, Rotary SM14 14K four-post with a bridge jack. Bay C: 14 feet wide, 28 feet deep, 12 feet 2 inch ceiling, Rotary SPO10 10K two-post low-profile version for a used-car department that services mostly sedans and small SUVs. All three bays were poured together, cured together, and commissioned within a single week last September.

The lesson from those three bays is that a proper dealer autolift garage build is not a mystery — it is a set of well-defined numbers that repeat from job to job. The GCs who follow the specification produce bays that work for 20 years. The ones who improvise produce bays that get retrofitted at year five for double the original cost. We provide the specification, the drawing, and the sequencing checklist. What the dealership does with them decides the quality of the finished shop.

Finishing the Autolift Garage: Lighting, Air, and Waste Oil

After the lift is installed and commissioned, three finishing steps make the bay actually usable. First is lighting — LED shop lights at 5,000K color temperature placed 3 to 4 feet outside the lift envelope on both sides. Cedar Falls dealers we have equipped run about 20,000 lumens per bay, which is bright enough for accurate paint inspection and diagnostic work. Second is air — a coiled retractable hose reel mounted overhead within 8 feet of the vehicle centerline, plumbed to the half-inch stub-up from the compressor loop. Third is waste-oil handling with a floor grate or basin under the lift and a fluid cart nearby.

None of these three finishes are heroic engineering. They are the difference between a bay a tech is happy to work in and a bay the tech resents by year two. When we hand over a completed autolift garage build to a dealer, all three finishes are part of the commissioning walk-through. For related reading, see our dealership shop build-out guide and shop lighting for lift bays.