What is the difference between stick-built and unitized curtain wall in terms of installation speed?

The Clock Starts Ticking the Moment the First Stick Goes Up

Walk onto any high-rise jobsite where the facade is going up, and the difference between stick-built and unitized curtain wall becomes visible within the first few days. One approach looks like a giant erector set being assembled piece by piece at height. The other resembles hanging prefabricated panels that lock into place like massive Lego bricks. The installation speed gap between these two systems isn’t marginal—it’s the kind of difference that can shave weeks off a construction schedule and let interior trades start months earlier.

Where the Work Actually Happens Makes All the Difference

With stick-built curtain wall, roughly 70 percent of the fabrication work happens on site. Vertical mullions get hoisted up and bolted to the floor slabs. Then horizontal transoms get attached between them. Then glass panels get lifted and glazed into the frames. Then seals get applied. Each step depends on the previous one being complete and properly aligned. On a multi-story building, this sequential process plays out floor by floor, and the facade installation often becomes the critical path that holds up everything else.

Unitized systems flip that ratio entirely. About 70 percent of the work moves into the factory, leaving only 30 percent for the jobsite. Complete wall panels—frame, glazing, seals, and sometimes even interior finishes—are assembled in controlled conditions, then shipped to site as finished units. The onsite work becomes a matter of lifting each panel into place with a crane and connecting it to brackets pre-fixed to the slab edge. That’s it.

A 2023 industry analysis noted that unitized systems can be installed in roughly one-third of the time required for stick-built systems. A Pennsylvania State University engineering study projected a stick-built curtain wall schedule at 80 days versus 52 days for an equivalent unitized installation—a savings of 28 days on the facade alone.

Real Numbers from Real Job sites Tell the Story

Installation rates paint an even clearer picture. Industry data shows stick-built crews typically achieve around 1 to 1.6 square meters per person per day. Unitized installations, by contrast, run at roughly 3 to 4 square meters per person per day. That’s more than double the productivity per worker.

For a 20-story building, those per-day differences compound dramatically. A well-organized unitized crew can close an entire floor of facade in a fraction of the time it takes to stick-build the same area. Some unitized installations have been documented achieving 30 to 50 panels per day with crane assistance.

The Weather Factor That Nobody Talks About Enough

Here’s something that doesn’t show up in the glossy brochures but matters enormously on actual jobsites: weather. Stick-built installation means glazing and sealing work happens at height, in whatever conditions the sky delivers. Rain delays sealing. Wind makes lifting glass panels dangerous. Cold temperatures affect sealant curing. Hot sun makes metal components expand and complicates alignment.

One project team working on a coastal high-rise in the Southeast learned this the hard way. They scheduled stick-built facade installation for a six-month window that happened to overlap with hurricane season. What should have taken 80 days stretched to 110 because of weather-related stoppages. The general contractor ended up paying overtime to compress the backend schedule, and the interior fit-out started three weeks late.

Unitized panels arrive at the site already sealed and glazed. The onsite connections between panels still require weatherproofing, but the volume of work exposed to the elements is dramatically smaller. A unitized crew can keep working through light rain because most of the critical sealing already happened indoors.

The Hidden Cost of Speed (or Lack Thereof)

Faster installation doesn’t automatically mean cheaper. Unitized systems carry higher upfront costs—more engineering, more factory tooling, more transportation logistics. The lead time from approved shop drawings to first delivery typically runs 16 to 24 weeks. Stick-built systems can start on site sooner because material fabrication lead times are shorter.

But here’s where the math gets interesting. The higher package cost of unitized systems often gets offset by reduced onsite labor hours, shorter crane rental periods, and earlier access for interior trades. One project manager put it bluntly during a industry panel discussion: “Pay more for the facade or pay more for the schedule. Pick your poison.” For projects where the construction program is tight—which describes most commercial work in the current market—the speed advantage of unitized installation frequently becomes the deciding factor.

When Stick-Built Still Makes Sense

None of this means stick-built is obsolete. For mid-rise buildings, irregular geometries, or projects where design changes are likely late in the process, stick-built offers real advantages. The ability to adjust on site—to tweak mullion positions, accommodate field conditions, or modify details as the building goes up—is something unitized systems simply can’t match.

Stick-built also makes sense for smaller facade scopes where the logistics of factory fabrication and panel shipping don’t pencil out. One estimator working on a five-story office building ran the numbers both ways and found that unitized would save only ten days on installation but add nearly 20 percent to the facade budget. The owner chose stick-built.

The Bottom Line on Installation Speed

If the question is purely about how fast the facade gets closed in, unitized wins. Period. The numbers are consistent across project types, geographies, and building heights. A unitized system can deliver building enclosure weeks or even months faster than a comparable stick-built installation. That speed translates directly into earlier interior work, faster project completion, and earlier revenue generation for the building owner.

But speed isn’t the only metric that matters. The right choice depends on building height, design complexity, site constraints, and the project’s overall schedule pressure. For high-rises, repetitive floor plates, and tight timelines, unitized is the clear leader. For everything else, stick-built remains a perfectly viable—and sometimes smarter—option.

For projects where panelized metal enclosure systems are part of the equation, manufacturers like Glostar have developed fabrication capabilities that support both approaches, with an emphasis on consistent quality and reliable delivery timelines that keep installation crews moving.