Otis Elevator Sizes: A 7-Step Checklist Before You Approve a Modernization

Why This Checklist Exists

I'm a quality compliance manager at an elevator modernization company. I review every spec package before it goes to the field—roughly 200 a year. In 2024, I rejected 6% of first submittals for shaft size errors, missing finish specs, and notes that said we'll figure it out during install. (Mental note: that phrase should be banned.)

If you're planning an elevator upgrade, this checklist is for you. It's also for anyone searching for 'Otis elevator sizes' and hoping a size chart will answer everything. The chart is useful. But the shaft is the real boss.

The 7-Step Checklist

Step 1: Measure the Shaft. Don't Trust the Drawing.

Most people start by asking what the standard Otis elevator sizes are. That's backwards. The hoistway width, depth, height, pit depth, and overhead determine which Otis elevator sizes will physically fit. A 75-millimeter difference can change the whole selection.

I learned this the hard way. In Q3 2023, we approved a cab modernization based on an old drawing. The drawing said the shaft was 2,150 mm deep. The actual shaft was 1,980 mm. That mistake cost $18,000 and delayed the project by three weeks. Everyone involved had the drawing. Nobody had a tape measure.

Measure it yourself, or have a qualified person do it. And write down the measurement date and who measured.

Step 2: Read the Capacity Plate, Not Just the Model Name

Otis elevator sizes are tied to rated load, counterweight weight, travel speed, and car configuration. The model name—say, Gen2—tells you the product family. The capacity plate tells you what the car was designed to carry. If you're modernizing, use the rated load from the plate before you change the cab.

If the rated load plate is missing or corroded, stop. Find the manufacturer's records or contact Otis with the serial number (see otis.com). Don't guess from the cab width.

According to Otis (otis.com), the Gen2 elevator uses flat coated steel belts, which may allow a smaller machine room than traditional rope systems. Verify current specifications.

According to ASME A17.1/CSA B44, elevator car capacity, door sizes, and hoistway clearances are code-regulated. Verify your current code at asme.org before relying on old specs.

Step 3: Check Door Openings and Landing Conditions

You can pick the right cab size and still fail at the doors. Measure the clear door opening, the door frame height, and the landing sill condition. A larger Otis elevator size may need a wider or taller door, and that affects the hoistway and wall pockets.

Door modifications are one of the places where we'll handle it later becomes a $4,000 change order. I've seen it happen more times than I can count.

Step 4: Coordinate With Other Trades

The elevator is rarely the only thing happening in the building. A furnace replacement Otis Orchards project we touched last year is a good example. The property manager was focused on the HVAC bid, and the elevator cab upgrade was almost an afterthought. The HVAC contractor assumed the old elevator shaft had the same dimensions as the drawings. It didn't. We measured before ordering, and only that caught it.

If you're doing a furnace replacement or any other mechanical work in the same building, don't work off separate drawings. Have a coordination meeting. Schedule the elevator shaft measurement before any wall or duct changes start.

Step 5: Specify Cab Finishes and Cleaning Requirements in Writing

This is the step I see ignored in almost every first submittal. People specify the Otis elevator sizes and the rated load, then leave the cab finish to standard. Standard is not a spec.

If you're using glass panels, specify the glass thickness, edge finish, tempered requirement, and the type of cleaner. In Q1 2024, we rejected 14 tempered glass panels because they were 6 mm instead of the specified 8 mm. The vendor said it was within industry standard. It wasn't our standard. They redid it at their cost.

For glass walls, use a non-ammonia glass cleaner. Ammonia can damage tinted and coated glass over time. It might look spotless for a week, then the coating starts to fail.

If the cab floor has tile, know how to clean grout before you pick the grout color. Sealed grout needs a pH-neutral cleaner and a soft brush. Acid-based cleaners on unsealed grout will eat the lines. And don't use a personal deodorant to mask a musty cab. I have seen someone try this—yes, with salt and stone deodorant—and it just left a film on the stainless steel. Remove the odor source, don't cover it.

Step 6: Ask What's Not Included Before You Talk Price

This is where my transparency rule kicks in. Ask what's not included before asking what's the price. Any vendor that refuses to answer or gives vague answers is showing you how the project will go.

In this industry, the quiet line items are: shaft preparation, door pocket modifications, car lighting upgrades, fixture swaps, freight, rigging, demolition and disposal, and temporary protection. A quote for $125,000 can become $147,000 before you install anything.

I went back and forth on a supplier quote for two weeks once. One vendor was $12,000 lower but would not list the freight and rigging. The other was higher but showed every fee on page one. I chose the higher one. It wasn't because I like spending money. It was because the total cost of ownership (i.e., the real number at the end) made sense.

Pricing for elevator modernization varies by region and scope. Based on project quotes I reviewed in December 2024, a full modernization for a mid-size commercial building can range from $110,000 to $180,000 per elevator. Verify current pricing. The exact number matters less than the line item list.

Step 7: Assign One Approver and Use a Written Checklist

The third time we ordered the wrong quantity of cab panels, I finally created a formal verification protocol. I should have done it after the first time.

Your protocol doesn't need to be complicated. It should include: shaft measurements, rated load, door clearances, cab finish samples, glass thickness, grout color, cleaning restrictions, and the names of everyone who approved each item. One person should have final sign-off.

If you're working with an Otis elevator service provider, ask them to review your checklist before you order. They can usually spot a missing dimension faster than anyone in the office.

Common Mistakes and Notes

Don't Assume Bigger Means Better

A larger Otis elevator size can mean a larger counterweight, a deeper pit, and a bigger machine room. Not every building wants that. More people per trip is nice, but not if it requires structural work.

Don't Skip the Final Clean

The final cleaning should be in the contract. That means no construction dust, no adhesive residue, no fingerprints on the glass, and no grout haze on the floor. If you don't specify it, you'll get it.

Don't Use the Wrong Cleaning Products

A glass cleaner that is fine in a retail window is not necessarily fine in an elevator cab with LED lighting and coated glass. And a tile floor with grout needs the right technique. If you don't know how to clean grout, ask the material manufacturer. It's a two-minute phone call that saves a re-grout job.

Here's the practical takeaway: the Otis elevator sizes are part of the decision, but they're not the whole decision. Measure the shaft, read the plate, coordinate with other trades, put the finishes and cleaning in writing, and ask what's not included. That list has saved me from embarrassing change orders more times than I can count. Trust me on this one: the extra twenty minutes before you order will save you a lot of headache later.