Curtain wall, window wall and storefront: three systems, three jobs

Why the distinction gets blurred

From the street, a curtain wall, a window wall and a storefront can look almost identical: aluminum grids holding glass. The differences are structural and organisational rather than visual, and they show up in how the system is anchored, who installs it, when in the schedule it goes in, and what happens at the floor line.

Getting the family wrong is expensive, because the choice affects the structure, the sequence and the trade packages — not merely the product order. It is worth being precise early.

Curtain wall: a continuous skin hung off the structure

A curtain wall is a non-load-bearing facade that runs continuously past the floor slabs and is anchored back to the structure at intervals. It carries its own weight and wind load back to those anchors and carries nothing else. Because it passes in front of the slab edges, it reads as an uninterrupted plane of glass and metal from outside, and the floor lines are usually concealed behind spandrel panels or shadow boxes.

That continuity is the point, and it is also the demand: the system has to accommodate building movement, differential slab deflection and thermal expansion across multiple storeys, and it has to manage water and air across a large, continuous, exposed surface. Curtain wall is engineered work with real anchorage design behind it.

It is normally the right answer on taller buildings, on facades where the design intends a continuous glazed plane, and where performance requirements are stringent.

Window wall: infill between slabs

A window wall sits between the floor slabs rather than passing them. Each floor's glazing is installed within its own opening, bearing on the slab below and sealed to the slab above. Slab edges are typically covered from outside by a separate treatment, but structurally the system stops at each level.

The practical consequences are significant and mostly favourable on the right project. Units can be installed floor by floor from inside, which reduces or removes swing-stage and crane dependency. The system can follow the construction sequence upward rather than waiting for a full structure. Individual units are smaller and simpler than a multi-storey curtain wall run.

The trade-offs are the horizontal joint at every slab — which must be detailed for movement, water and fire-stopping as applicable — and the fact that the facade reads with a floor-line rhythm rather than as a continuous plane. Window wall is common on residential mid-rise and multifamily work for exactly these reasons.

Storefront: non-load-bearing framing at grade

Storefront framing is a lighter, generally single-storey system used at ground level: retail frontages, lobbies, entrances, restaurants, commercial units. It is typically installed between a floor and a header within a prepared opening, and it is designed for pedestrian-level conditions rather than multi-storey wind and movement.

Storefront is the least structurally demanding of the three and the most sensitive to the surrounding construction being accurate. It is also the family most closely tied to entrance hardware, because a storefront almost always contains doors, and the door hardware and its coordination with access control, closers and thresholds is usually the fiddly part of the package.

It is the wrong choice when the conditions are really curtain-wall conditions: significant height, large spans, high wind exposure or stringent performance criteria.

How to tell which one a project needs

• Does the glazing run past the slab edges continuously? That is curtain wall.
• Does the glazing stop at each slab and start again above? That is window wall.
• Is it a single-storey, at-grade frontage with entrances? That is storefront.
• Can the facade be installed from inside, floor by floor? That points strongly to window wall.
• Are multi-storey movement and deflection accommodation required? That points to curtain wall.

What changes about cost and coordination

Curtain wall carries the highest engineering and installation content, needs the most external access, and interacts most with the structural design. Window wall shifts cost toward repeated units and slab-edge detailing while reducing access cost. Storefront is the lightest package but tends to carry disproportionate hardware and finish coordination.

Schedule is often the deciding factor rather than material price. A system that can be installed from inside on a residential tower may be cheaper in total than a nominally similar system that requires external access for months.

How this relates to Gloria Glass's existing services

Our storefront glass service page describes work we perform — measuring, specifying, coordinating fabrication and installing glass in storefront conditions. The Everest pages describe manufacturer aluminum systems and the supply and project-support route around them. A project may involve one, the other, or both, and we will say plainly which applies.

Everest identifies its curtain-wall family as 30 000 and its window-wall family as 37 000. Detailed Colorado documentation for both follows the manufacturer data review; nothing on this page should be read as a performance claim.