One is built for traffic, the other for weather. Why they are different products, why the prices differ, and which one your opening needs.
A commercial storefront door is built for traffic: hundreds of people a day, an ADA threshold you can roll over, a closer that shuts it behind them, and hardware that survives being kicked. A terrace or balcony door is built for weather: compression gaskets, a drained sill, a multi-point lock, insulated glass, and a frame rated like a window. Put a storefront door on a terrace and the apartment is cold and wet; put a terrace door on a shop and it is worn out in a year and does not meet egress code. They are different products for different jobs, and the price difference reflects the hardware on one and the frame on the other.
| Feature | Commercial storefront door | Terrace / balcony door |
|---|---|---|
| What it is | Aluminum entrance door in a storefront frame: narrow, medium or wide stile | A residential door in a window system: hinged (French), sliding, lift-slide or tilt-slide |
| Built for | Hundreds of openings a day, the public, code egress | A family, a few times a day; weather, security, comfort |
| Glass | Tempered, often 1/4″ monolithic or 1″ IGU; full-height | Insulated Low-E unit, often triple; tempered |
| Threshold | Low or flush, ADA; a saddle; not weathertight by design | Weathered sill with gaskets and drainage; a step or a low-profile weathered threshold |
| Seal when closed | Sweeps and brush seals; air leaks by design | Compression gaskets on all sides; near-airtight |
| Hardware | Closer, pivots or continuous hinge, push/pull, panic device, deadlatch | Multi-point lock, lever handle, tilt-turn or lift-slide gear |
| Thermal performance | Poor to moderate; many systems are not thermally broken | Good to excellent; thermally broken, rated as a window |
| Swing | Out (egress) with a closer | In or out, or slides; no closer |
| Cost per opening | Lower for the door; higher for the hardware | Higher; the frame is a window-grade system |
| Where it belongs | Shops, lobbies, offices | Apartments, houses, terraces, balconies |
A storefront entrance is an aluminum door leaf — narrow, medium or wide stile — hung in a storefront frame on pivots or a continuous hinge, with a surface or concealed closer, push and pull hardware, and usually a panic device or a deadlatch. The threshold is a low aluminum saddle so a wheelchair and a delivery cart can cross it, which means it is not weathertight: a brush sweep and a rain drip are all that keep the weather out, and some air always moves. Many storefront systems are not thermally broken; the ones that are still lose more heat than any window-grade door, because the design priorities are traffic and egress, not U-factor. It swings out, because the code says an egress door must. Coney Island Avenue and 3915 Flatlands Avenue are storefront doors, with buzzer access control on the former.
A terrace or balcony door is a member of a window system — Cortizo, Reynaers, Alutech, Pella — and is built like one: a thermally broken frame, an insulated Low-E unit (triple on the Ocean Parkway house), compression gaskets on every edge, a multi-point lock that pulls the leaf tight when the handle turns, and a weathered sill that drains. It comes as a hinged French door, a tilt-and-turn door, a sliding or lift-slide door for wide openings, or a tilt-slide. There is no closer; it stays where you leave it. The threshold is either a step or a low-profile weathered sill, and the low sill is the one place where a terrace door makes a compromise: below about 20 millimetres of upstand the drainage has to be very good, and we detail it with a channel drain outside.
The commonest mistake is a landlord ordering a storefront door for a rooftop or terrace because it is cheaper, and getting a door that leaks air and water and cannot be locked properly from inside. The second is an owner wanting a terrace-style lift-slide on a shop, which cannot take a closer or a panic bar and does not meet egress. The third is a mixed-use building where the ground-floor entrance and the upper-floor terrace doors are ordered as one package; they should be two systems — storefront below, window system above — and that is how 1192 Gravesend Neck Road was done. See storefront vs curtain wall for the same distinction one level up.
You can, and it will leak air and water and be cold; it is not built for weather. A terrace door from a window system has compression gaskets, a drained sill and a multi-point lock. Use the storefront door on the shop.
Not usually. It cannot take a closer or a panic device, does not meet egress requirements for a commercial entrance, and its hardware is not built for public traffic.
Per opening, the terrace door, because the frame is a window-grade thermally broken system with insulated glass. The storefront door is cheaper as a leaf but its commercial hardware adds up.
A sliding terrace door whose leaf lifts off its seals when the handle turns, slides freely, and drops back onto the seals when closed — the way to get a wide opening that still seals like a window.
A weathered sill usually has some upstand. Low-profile and flush sills exist and we install them, with a channel drain outside; below about 20 mm of upstand the drainage design does the work.
Storefront Doors Balcony & Terrace Doors Sliding Doors Storefront vs Curtain Wall Commercial Doors
About this page. Written by Alex GC Inc. d/b/a Alex Glass Construction and reviewed before publication by Aleksandr Chernovolenko, Managing Partner, with our design and estimating lead and a field foreman. Our foremen hold the NYC DOB Site Safety Training supervisor card and our crews the 40-hour worker card; we are certified to fabricate, install and service Alutech and Everest aluminum systems. Facts are drawn from our own projects, manufacturer test data and the applicable codes; where we are giving an opinion, we say so. Last reviewed September 2026. Credentials
Send a photo of the opening and tell us what is behind it — a shop or a living room. We will tell you which door and quote it.
