What Is a Curtain Wall? A Guide for Building Owners

A curtain wall is an exterior wall system made of aluminum framing and glass. The building’s own structure carries the load, and the wall hangs from it like a curtain. That’s where the name comes from.

If your building project includes a glass exterior, the term curtain wall will show up in your architect’s plans and your contractor’s bids. The system you choose shapes your budget, your schedule, and how the building looks and feels for years. Changing it after the plans are set can delay the project and push the budget up.

Here’s when a building calls for a curtain wall, how it differs from other glass systems, what it’s made of, and what to ask before you choose.

When a Building Calls for a Curtain Wall

Curtain walls suit buildings where the exterior has to do more than a storefront can. A few common situations show where one fits.

Planning a new multi-story office building is the clearest case. A glass curtain wall covers the exterior across several floors in one continuous face. The whole front of the building reads as a single design.

If you manage a school or campus building with an aging exterior, a high-performance curtain wall can replace it. Thermal breaks in the frame slow heat moving through the metal, and the added glass brings daylight into classrooms and hallways.

A dark lobby or common area is another. Large glass areas bring natural light deep into the building and give tenants and visitors a clean, modern first impression.

An addition or an unusual building shape also points to a curtain wall. Custom shapes and designs are where stick-built systems, described below, work well.

How a Curtain Wall Differs From a Storefront or Window Wall

The three systems look alike from the sidewalk, and they use similar materials. They differ in where each one goes and how it attaches to the building.

A storefront system (link to “What Is a Glass Storefront System? A Simple Guide” blog) covers the ground level, usually one story tall, and includes the entrance doors and display windows. You see it on retail shops, restaurants, and office lobbies. A curtain wall covers the exterior across multiple stories, hanging from the structure floor after floor.

Window walls also use aluminum and glass. Each section sits between two floors and attaches at the floor slabs. A curtain wall runs past the floor edges, so the glass can cover the whole front of the building.

What a Curtain Wall System Is Made Of

A curtain wall system has three main parts: the aluminum frame, the glass, and the anchors that connect the frame to the building.

The frame is a grid of vertical and horizontal aluminum pieces. Its vertical pieces are called mullions. Glass, also called glazing, fits into that grid. The right glass depends on what the building needs for strength, safety, heat, and light. Tempered and laminated glass are both common in commercial glazing. Tempered glass is heat-treated for strength, and laminated glass holds together when it breaks. Some systems also mix solid metal or stone panels in with the glass.

Anchors attach the frame to the building’s structure, usually at the floor edges. They carry the wall’s weight and the wind pressure into the building’s frame.

Curtain walls come in two main types. Crews assemble stick-built systems piece by piece on the job site. This allows more customization and suits mid-rise buildings and unique designs. Unitized systems arrive from the factory as pre-assembled panels, glass included. That makes installation more efficient on taller buildings and larger projects. Columbia Glass & Mirror designs and installs both types of curtain wall systems. The best fit depends on the building’s height, design, and schedule.

Other options include point-supported glass systems, which keep the visible framing to a minimum. High-performance systems add thermal breaks, which are insulating pieces inside the frame.

How Curtain Walls Are Installed

Curtain wall installation starts with exact measurements of the building. Engineers then fit the system to your structure and design.

With a stick-built system, the crew sets the anchors, builds the frame on site, installs the glass, and seals the joints. Unitized panels arrive finished. The crew lifts them into place, connects them to the anchors, and seals the joints between them. Sealing keeps the wall weathertight, which is why trained glazing installers handle this work.

The timeline depends on the size of the wall and the system type. Ask for a schedule along with your quote.

What to Consider Before Choosing a Curtain Wall

Most owners and property managers weigh three things: the budget, the schedule, and the disruption to the people using the building. Early decisions affect all three. Engineers design a curtain wall around your specific building, so bring a glazing contractor in during design. The glass, frame, and anchors all affect each other.

Cost depends on the system type, the wall’s size and height, the glass, the frame finish, and site access. Because those details vary on every project, a custom quote based on your plans gives you an accurate number.

Ask your architect or contractor these questions before you commit:

• Which type does the design call for, stick-built or unitized, and why?
• What glass does the plan specify, and what performance does it need to meet?
• Who engineers the system, and who installs it?
• How does the wall attach to the building’s structure?
• How will installation affect your schedule and access to the building?

Planning a Curtain Wall for Your Building?

A professional evaluation shows whether a curtain wall fits your building or whether another glass system suits it better. Business owners, property managers, and facility decision-makers in Columbia, Jefferson City, Lake of the Ozarks, and surrounding Mid-Missouri communities can work with Columbia Glass & Mirror to find the right option.

Contact Columbia Glass & Mirror at (573) 874-6985 to schedule a consultation.