Automatic Door Spec Guide for Commercial Projects

An automatic door looks like a solved problem: a sensor, a motor, the door opens. That is exactly why specifications go wrong. The wrong operator stalls under real traffic. One motion sensor leaves a blind spot a child walks into. An airlock specified without the interlock sequence becomes a revolving door for conditioned air. For architects, contractors, and building owners, getting the automatic door specification right is the difference between a lobby that moves people and one that backs up at 8:55 a.m.

This guide covers what actually matters when specifying commercial automatic doors — operator types, safety sensors, traffic capacity, and ADA compliance — so your next opening passes inspection and holds up in daily service.

1. What an Automatic Door System Actually Is

An automatic door is not a door with a motor bolted on. It is a coordinated system: the door leaf, the operator (drive unit), the activation sensors, the safety sensors, the controller, and the power supply. Each part has a failure mode, and the system is only as good as its weakest link.

For aluminum-framed commercial automatic doors, the build is:

• A door leaf in aluminum frame — sliding, swinging, revolving, or folding
• An operator (belt, screw, or cam drive) sized to leaf weight and cycle rate
• Activation sensors that tell the door when to open (motion, presence, mat, push)
• Safety sensors that stop or reverse the leaf if something is in the path
• A controller that sequences opening, hold-open, and closing, plus interlocks for airlocks

2. Operator Types and Where They Fit

The operator decides the door’s character: how it opens, how fast, and how much traffic it absorbs. Choosing against the opening — not the catalog — is the first spec decision.

Spec tip: Match the operator to the leaf weight, not the opening width. A bi-part sliding operator rated for two 90 kg leaves will stall if you hang two 140 kg insulated leaves on it. Confirm the rated leaf weight against your actual door build before ordering.

3. Safety Sensors: Activation Is Not Safety

This is the gap where most automatic door injuries and code failures happen. Activation sensors (motion, mat) tell the door to open. Safety sensors (presence, infrared curtain, pressure edge) stop it from closing on someone. They are different devices with different jobs, and one cannot cover the other.

• Activation: Microwave / PIR motion at the approach; floor mat at the threshold; push plate at the jamb.
• Safety (closing path): Active infrared (AIR) curtain across the leaf path; monitored contact edge on swing leaves; presence sensor to re-open if someone steps back in.
• The trap: A motion sensor only detects approaching movement — a child standing still in the closing path is invisible to it. A presence / safety curtain sees the standing child. Spec both, and require the safety sensor to be monitored (the controller knows if it fails).

Spec tip: Require the safety sensor to meet ANSI/BHMA A156.10 for power-operated pedestrian doors, with monitored safety devices wired to the controller. Unmonitored “dumb” edges pass nothing at inspection.

4. Traffic Capacity and Sizing

An automatic door sized for average load fails at peak. Size against the worst 15 minutes of the day, not the hourly average.

Spec tip: Throughput is limited by the slowest stage — often the person fumbling for the badge, not the door. If the lobby queues at peak, add a second opening or a wider bi-part before you buy a faster operator. The operator is rarely the bottleneck.

5. ADA and Accessibility (ADA / ICC A117.1)

Accessible automatic doors have hard limits that affect the operator and the activation method:

• Clear width: Min 32 in (815 mm) of clear opening for the accessible leaf.
• Opening force: Max 5 lbf (22 N) to initiate, max 15 lbf (67 N) to hold open against the operator. Most automatic doors meet this by design — but a worn belt or mis-set closer can push it over.
• Activation height: Operable parts (push plate, switch) between 34–48 in (865–1220 mm).
• Activation method: Motion / mat activation is preferred at accessible openings; a push-only plate fails the “power operation” intent if the user must physically open it.
• Power failure: Inspectors check fail-safe behavior — the door must go to a known safe state (open, closed, or free-swing) per the egress plan, not just “stop where it is.”

Spec tip: State the power-fail behavior in the spec. “Fail-safe open” suits fire egress; “fail-safe closed” suits security or environmental control. Pick one and write it, or the installer picks for you.

6. Power, Backup, and Integration

An automatic door is only automatic when it has power and a signal. Two items get skipped at spec and bite at commissioning:

• Backup power: For egress and life-safety openings, require battery backup sized to N cycles after utility loss (commonly 200–500 cycles). Confirm the battery is monitored and reports low-charge to the BMS.
• Integration: Tie the operator to the access control, fire alarm, and BMS. A door that opens on fire alarm but the controller wasn’t told will do nothing. Define the input signals (fire release, lock-down, free-pass) at spec, not at wiring time.
• The trap: Specifying the door, the access system, and the fire panel from three vendors with no defined interface means three parties pointing at each other on commissioning day. Name the integration owner.

7. Finish and Frame (Aluminum Specifics)

The frame is the part occupants see and the part corrosion attacks first.

Spec tip: For exterior automatic door frames in high-UV or coastal sites, specify PVDF (AAMA 2605), not polyester. The frame sees weather 24/7; polyester chalks within years and the entry looks tired while the glass stays clear.

Conclusion

Automatic door projects fail in the field for predictable reasons, and almost all of them are set at the specification stage. The pattern across every failure mode in this guide — wrong operator for leaf weight, activation-only sensing with a blind spot, undersized for peak traffic, undefined power-fail state, no integration owner — comes down to one thing: the door was specified as a leaf plus a motor instead of as a system.

The operator, the activation and safety sensors, the controller, the power backup, and the integration interface are one coordinated package. A sliding operator rated for the wrong leaf weight stalls. A motion sensor with no safety curtain injures. A door with no defined power-fail behavior fails the egress inspection. The spec that holds up is the spec that names the system and the party responsible for it.

That is the practical advantage of sourcing automatic doors as a coordinated package rather than stitching the leaf, operator, sensors, and controls from separate vendors. One responsible source means one controller, one shop drawing, one commissioning, and one party accountable when the lobby has to move 60 people a minute. For architects and contractors, that removes the most common causes of rework and callback — which is where automatic door budgets actually break.

Specifying automatic doors on an upcoming project? Send us your opening schedule, required operator type, traffic estimate, activation and safety method, and integration signals. We’ll return a coordinated, inspection-ready specification — leaf, operator, sensors, and controls under one number — within 48 hours.

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Frequently Asked Questions

1. Which automatic door operator type should I specify?

Match the operator to traffic and space, not the catalog photo. Use sliding (single or bi-part) for high-traffic retail and hospital entries where you have side wall to stack the leaf. Use swing operators for existing openings with narrow jambs and no room to slide. Use revolving for very high-volume lobbies where you also need thermal and acoustic control. Use folding / telescopic when you need a wide clear opening in a tight footprint. In every case, size the operator to the actual leaf weight — insulated and glazed aluminum leaves are heavier than they look.

2. Why is one motion sensor not enough for safety?

A motion sensor only detects approaching movement; it cannot see a child or cart that is standing still inside the closing path. Safety requires a separate, monitored presence / active-infrared curtain across the leaf path that the controller checks continuously. ANSI/BHMA A156.10 requires the safety devices to be monitored so a failed sensor forces a safe state instead of silent failure. Spec activation and safety as two distinct, monitored functions — never as one “sensor does both” line item.

3. How do I size an automatic door for real traffic?

Size against peak, not average. Count the worst 15 minutes of the day (building open, shift change, lunch rush) and divide by the throughput of your chosen configuration: a single sliding leaf moves roughly 20–30 people/min, a bi-part 40–60, a 3-wing revolving 60–80 continuous. If the queue forms at the badge reader or the turnstile, the door width will not fix it — add an opening or widen to bi-part. Throughput is gated by the slowest stage, usually the person, not the operator.

4. What happens to automatic doors when power fails?

It depends on what you write in the spec, and inspectors check it. Fail-safe open sends the leaf to the open position — right for fire-egress and life-safety openings. Fail-safe closed secures the opening or holds environmental control — right for security or cold-storage interfaces. Free-swing lets the leaf be pushed manually. Define the required behavior per opening, require battery backup sized to the needed post-loss cycles (commonly 200–500), and confirm the battery reports low charge to the BMS.

5. What drives automatic door price, and is cheapest the lowest cost?

Price scales with operator type, leaf size and weight, sensor suite (activation + monitored safety), finish, integration complexity, and backup power. A basic single sliding leaf with one motion sensor costs far less than a bi-part with monitored safety curtains, PVDF frame, BMS integration, and 500-cycle battery backup — but the cheaper build often carries the higher lifecycle cost: a stalled operator under peak load, an injury from a blind spot, a failed inspection on power-fail behavior, or three vendors blaming each other at commissioning. The lowest total cost is the door specified correctly once, delivered as one coordinated system, commissioned by one accountable source.

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