Your elevator is down. The mechanic is on-site. "We need to order the part." Five days later you're still explaining to tenants why the elevator doesn't work. Meanwhile, complaints accumulate, accessibility violations add up, and your building looks incompetent. If you had $2,000 worth of critical parts sitting in a storage closet, that same breakdown becomes a two-hour repair. Here's what every building should stock, what it costs, and why the right inventory eliminates most elevator downtime.
Why Parts Inventory Matters
Every day of elevator downtime costs you money and credibility. Tenant complaints stack up. ADA violations accumulate if you only have one elevator. Emergency service calls cost more. And you're at the mercy of your vendor's supply chain.
The average emergency repair takes 3-5 days when parts need to be ordered. Most breakdowns involve predictable failures: motor starters, proximity sensors, door components, buttons. These items cost $50-$800 individually. When you stock them yourself, a 5-day outage becomes a 2-hour repair.
The math is simple. You'll spend $2,000 upfront to build a basic inventory. One avoided emergency service call pays for half of it.
Critical Parts to Stock (By Equipment Type)
Hydraulic Elevators
Motor starter/contactor: $200-$500. This component fails regularly due to heat stress. When it goes, the elevator won't run at all. Stock one for each elevator or share across buildings if you manage multiple properties nearby.
Proximity sensors: $50-$150 each. These sensors detect door position and car location. They fail often because they're mechanical and get misaligned. Buy extras because they're cheap and essential.
Door operator belts: $100-$200. Belts wear out. They stretch, crack, or snap. When they fail, doors won't open. Having one on-site means the mechanic fixes it immediately instead of waiting three days for shipping.
Car station buttons: $25-$75 each. Buttons break because people abuse them. Vandalism, heavy use, and moisture all cause failures. Stock five per elevator because they're inexpensive and failures are frequent.
Fire service key switch: $150-$300. Required by code in every building. When this fails, firefighters can't control the elevator during emergencies. Stock one because the liability exposure is massive.
Traction Elevators
Door operator motor: $400-$800. This motor runs constantly, opening and closing doors hundreds of times daily. When it burns out, the elevator is dead until replaced. Stock one if you can afford it, otherwise have your vendor keep one for you.
Encoder: $300-$600. The encoder tracks car position. If it fails, the elevator won't level properly or may not run at all. These are equipment-specific, so verify compatibility before purchasing.
Safety edge/detector: $200-$400. This device prevents doors from closing on people. When it fails, doors won't close properly or may create a safety hazard. Code requires it, so failures can shut you down.
Leveling sensors: $150-$300. These sensors ensure the car stops level with each floor. When they fail, you get a 1-2 inch height difference that creates a trip hazard and ADA violation. Inexpensive insurance against liability.
Power supply boards: $300-$600. Electronic boards fail due to power surges, age, or environmental factors. Generic power supplies may work across equipment types. Consult your mechanic before purchasing.
All Elevator Types
Intercom/phone handset: $100-$200. Code requires working emergency communication. When the phone fails, you're liable if someone gets trapped. Stock one spare because failures happen and testing is monthly.
Emergency lighting battery: $50-$100. Backup lighting is required by code. Batteries die regularly. Replace every 3-5 years and keep one spare.
Position indicators: $100-$300. The display showing which floor the elevator is on. These fail due to power surges or component failure. Having a spare keeps your building looking professional.
Hall call buttons: $50-$100. These break frequently due to vandalism and wear. Stock five because they're cheap and visible failures make your building look neglected.
OEM vs Aftermarket Parts
You have two choices when sourcing parts: original equipment manufacturer (OEM) or aftermarket suppliers.
OEM parts come from the company that made your elevator. They cost more but guarantee compatibility. Your maintenance vendor may require OEM parts to maintain warranty coverage. If your equipment is under warranty or less than 10 years old, stick with OEM.
Aftermarket parts cost 30-50% less but require more diligence. You need to verify specifications match your equipment. Some vendors refuse to install aftermarket parts because they don't want liability if something fails. Generic components like sensors, buttons, and belts usually work fine aftermarket. Complex electronic boards are riskier.
The hybrid approach: Stock aftermarket parts for common, low-risk failures like buttons and sensors. Use OEM for critical electronic components and anything your vendor specifically requires. This gives you cost savings without adding risk.
What Your Contract Says
Your maintenance contract determines whether you're allowed to stock and provide parts.
Full maintenance contracts typically include all parts in the monthly fee. The vendor controls sourcing and markup is already baked into the contract rate. You can still negotiate the right to provide common items like buttons and sensors.
Examination contracts (also called oil/grease contracts) exclude parts entirely. You pay for labor and provide all parts yourself. This gives you full control over sourcing and potential savings, but requires more involvement.
Hybrid contracts vary. Some cover major components but bill separately for common wear items. Read your contract carefully to understand who provides what.
Most vendors will push back if you try to provide parts yourself. They make 50-200% markup on parts and don't want to lose that revenue. If you're negotiating a new contract, include language that allows you to provide parts for non-warranty equipment. On older elevators (15+ years), you have more leverage because the vendor can't threaten warranty voidance.
Building Your Inventory
Start with $2,000 in critical parts based on your equipment type and breakdown history. If you don't know what fails most often, ask your mechanic or review past invoices.
Add parts based on callback patterns. If you've replaced the same component three times in two years, stock a spare. If your building has multiple identical elevators, you can share inventory across units.
Storage requirements are minimal. Most parts fit in a standard storage closet. Keep them in their original packaging and label clearly. Avoid temperature extremes and moisture. Certain electronic components need climate control, but most mechanical parts tolerate normal building conditions.
Track what you have and update inventory when parts get used. A simple spreadsheet works. Include part numbers, purchase dates, and which elevator each item fits.
Your Contract Determines Your Options
Whether you're allowed to stock parts, who provides them, and what markup you pay all depend on your maintenance contract language. Different contract types give you different levels of control and different cost structures.
Upload your contract to Contract Scanner and see exactly what's included, what's billable, and whether you have the right to source your own parts. Most property managers discover they're paying 100-200% markup on parts they could source themselves for half the price.