Curtain wall
System selection, thermal performance and installation sequencing for both types.
Curtain wall →← Technical guides
Curtain wall
Unitized vs. stick-built curtain wall
Unitized curtain wall is fabricated and glazed into finished panels in a shop, then hoisted and set as complete units. Stick-built curtain wall is assembled piece by piece at the building — mullions first, then glass — from swing stage or lift. Unitized costs more per square foot but installs faster with less field labor and weather exposure; stick-built is cheaper on smaller, lower, access-friendly elevations.
What is the difference between unitized and stick-built curtain wall? For GCs and architects deciding a system type before bid.
01
The real difference is where the glazing happens
Both systems produce the same thing: a non-load-bearing aluminum-and-glass facade hung off the building structure. The distinction is the location of the labor. Unitized work happens on a shop floor under controlled temperature, lighting and cleanliness, where gaskets seat correctly and structural silicone cures at a known rate. Stick-built work happens on the building, in whatever weather the schedule delivers.
That single difference drives almost every downstream consequence — cost structure, schedule shape, quality control, weather risk and how much of the building has to be accessible from the outside.
02
Comparison
| Factor | Unitized | Stick-built |
|---|---|---|
| Where it's glazed | Shop, into complete floor-height cassettes | At the building, glass set into field-assembled framing |
| Field labor | Low — setting and anchoring only | High — mullion assembly, glazing, gasketing all in the field |
| Access | Crane, monorail or interior stack setting; often no swing stage | Swing stage, mast climber or lift for the full elevation |
| Weather exposure | Envelope closes each shift as panels are set | Openings can stay open between framing and glazing |
| Schedule | Longer lead, much faster on-site | Short lead, slower on-site |
| Quality control | Shop water-testing before delivery | Field mockup and field testing only |
| Tolerance handling | Anchors adjustable in three axes; requires accurate survey up front | Absorbed progressively in the field as work proceeds |
| Typical fit | Mid- and high-rise, repetitive elevations, occupied buildings | Low-rise, lobbies, single bays, irregular one-off elevations |
03
Where the cost crossover sits
Unitized carries a higher material and fabrication cost per square foot, plus tooling and shop-drawing effort that stick-built does not need at the same depth. It pays that back in field labor, access equipment and schedule duration. The crossover is not a fixed number of floors — it is a function of elevation repetition, access cost and how expensive a day of schedule is on that project.
Practical rule: if the same panel repeats dozens of times, if swing-stage access is difficult or restricted, or if the building is occupied, unitized usually wins even at a higher unit price. If the elevation is one or two stories, ground-accessible and geometrically irregular, stick-built almost always wins.
04
What to decide before bid
Three inputs settle the system type earlier than most teams expect: the access strategy, the structural tolerance of the slab edges, and whether the building will be occupied during installation. Get a real survey of slab edge deviation before committing to unitized — the anchor adjustability has to cover the actual drift, not the drawn dimension.
- Access strategy
- Crane availability, street closure permits, wind exposure and roof rigging capacity often decide the system before cost does.
- Slab edge tolerance
- Unitized anchors need documented three-axis adjustability sized to real survey data, not to nominal drawings.
- Occupancy
- Occupied buildings push hard toward unitized, because the envelope can be closed at the end of every shift.
- Lead time
- Unitized front-loads shop drawings, approvals and fabrication. That time has to exist in the schedule before mobilization.
Related questions
Is unitized curtain wall always more expensive?
Per square foot of material, generally yes. Installed, often no — unitized removes field labor, access equipment time and schedule duration, and those line items frequently exceed the material premium on repetitive mid- and high-rise elevations.
Can stick-built curtain wall be used on a high-rise?
It can and historically was, but it requires full-elevation exterior access for the duration and leaves the envelope open between framing and glazing. On occupied or wind-exposed towers that risk profile is usually unacceptable.
Which system handles building movement better?
Unitized, generally. The stack joint between panels is a designed movement joint, so inter-story drift and thermal movement are accommodated by the system rather than by the sealant.
Where this applies
Services this guide relates to.
Storefront systems
Where the elevation is low-rise, storefront framing may be the correct system instead.
Storefront systems →Weatherproofing & silicone
Both systems depend on the perimeter joint program at slab edges and transitions.
Weatherproofing & silicone →More guides
Next step
Ready to scope the actual project?
Send drawings, specifications, a hardware schedule or a written scope description. Every submission is reviewed and answered with next steps.