Curtain Wall Systems in Saudi Arabia: Types, Performance and Cost Factors

Curtain wall systems are non-load-bearing aluminum and glass façades that hang from a building’s floor slabs. They carry their own weight, pass wind loads back to the structure, and keep rain and heat out. In Saudi Arabia, the specification work comes down to four things: solar heat, wind-borne dust, coastal salt and fire safety at the slab edge.

A glass façade looks simple from the street. Behind it sits an engineered kit of extrusions, gaskets, anchors and glazing that has to survive a Riyadh July and a Jeddah salt breeze.

This guide explains how curtain wall systems work, which type suits which job, and what Saudi conditions change. It’s written for owners, developers and contractors who are still learning the subject and may soon need to request a quotation. You’ll get the vocabulary, plus the testing and cost questions to put in front of any fabricator, in plain terms.

What Are Curtain Wall Systems?

Curtain wall systems are lightweight building envelopes, usually aluminum framing filled with glass or opaque panels, fixed to the edges of floor slabs instead of standing on the ground. Arabic-speaking site teams often write the term as (كرتن وول). The word “curtain” is literal: the wall hangs off the structure like a drape.

Here’s the part people miss. Curtain wall systems don’t hold the building up. The concrete or steel frame does that. The wall only carries its own weight and the wind pressing on it, then hands both to the slabs through anchors.

That’s why curtain wall systems can be so thin and so tall. Glass runs floor to floor, daylight reaches deep into the plan, and the frame arrives in sizes a crane can lift. They’re the standard answer for office towers, hotels, hospitals and retail podiums where owners want a lot of glass and a fast enclosure.

If you’re comparing curtain wall systems with other envelope options, our guide to exterior façade design covers how glazed and solid skins work together on a single elevation.

The Parts of a Curtain Wall

Every one of the curtain wall systems on the market, whatever its brand, is built from the same short list of parts. Knowing them makes a drawing or a quotation far easier to read.

Mullions and Transoms

Mullions are the vertical members and transoms are the horizontal ones. Both are usually extruded aluminum, often alloy 6063 in a T5 or T6 temper. Visible face widths of roughly 50 to 65 mm are common, though architects push them narrower or wider for the look they want.

What you can’t see matters more. The depth of a mullion, measured into the building, is set by how far it spans between anchors and how hard the wind pushes. A deeper section resists bending better and costs more. Two façades with identical glass can need very different frames.

Glass and Spandrel Panels

Vision glass is almost always a double-glazed unit, two or more panes separated by a sealed, gas-filled gap, typically around 24 to 32 mm thick overall. A low-emissivity coating on one surface cuts solar heat without turning the glass dark. For more on unit build-ups, see our page on double-glazed glass.

Spandrel panels are the opaque bands that hide the slab edge, ceiling void and services behind. They’re usually glass with an opaque backing, or metal, and they sit over insulation. Their fixing matters for fire safety, which we’ll get to shortly.

Gaskets, Pressure Plates and Thermal Breaks

EPDM or silicone gaskets seal the glass against the frame. In a common pressure-plate design, a metal plate screwed to the mullion clamps the glass, and a snap-on cap covers the screws. Hence the grid of thin lines on many glass buildings.

Metal conducts heat quickly, so a polyamide thermal break splits each aluminum section into an inner and outer half. Without it, a hot frame would pour heat straight into an air-conditioned lobby.

Anchors and Drainage

Anchors fix the mullions to the slab edge. They’re adjustable in three directions, because concrete is never perfectly where the drawing says, and they let the wall move a little.

Water management follows a simple rule: assume some rain will get past the outer seal, then give it an exit. Most systems use an internal drained cavity with weep holes so that water runs out instead of in.

Stick-Built, Unitized and Semi-Unitized Curtain Wall Systems

Curtain wall systems split into three families by how they’re put together. The choice affects schedule, labor, quality control and cost more than almost any other early decision.

Table 1: Comparing assembly methods

A trade article from Construction Specifier in 2018 explains the trade-off well. Stick-built assemblies can offer lower upfront cost and shorter lead times, while unitized systems move work into a controlled factory and shorten site time. Its logic holds in Saudi Arabia, where a sealing joint made in dust and 40 °C afternoon heat is harder to get right than one made in a workshop.

A caution before you pick. The method has to match the fabricator. A shop built for stick-built supply can’t simply produce unitized panels, and that capability should be confirmed in writing before the design is frozen around it.

Curtain Wall vs Window Wall vs Storefront

Three glazing types get confused constantly, and mixing them up causes real budget errors.

Storefront is the lightest. It’s typically a single-story, ground-level frame, glazed from the outside or inside, used for shop fronts and entrances. Spans are short and wind loads modest.

Window wall sits between floors. Each unit stands on the slab below and stops at the slab above, so the slab edge shows in the elevation. It’s common in residential towers.

Curtain wall systems pass in front of the slab edge and can run continuously across many floors. That continuity gives the cleanest glass elevation and the highest structural and performance demands.

Metal Architecture magazine has a short comparison of storefront and curtain wall applications and performance considerations if you want a second source. Rule of thumb: storefront suits the ground floor. Choose window wall when each floor is a separate compartment, and curtain wall systems when you want one continuous glass skin.

Why Saudi Conditions Change the Specification

Most published guidance on curtain wall systems is written for temperate climates. A façade that performs well in a temperate city can underperform badly in Riyadh if nobody adjusts the glass, the seals or the finish.

Heat and Solar Gain

Solar heat gain is the number to watch. Two figures describe glass: the U-value, which is how readily heat passes through, and the solar heat gain coefficient (SHGC), which is how much sun gets in. Glass with a low SHGC keeps direct sun out of the building.

Saudi Building Code part 601 covers energy conservation in non-residential buildings and includes envelope requirements for glazing. The exact limits depend on building type and climate zone, so always read the current edition rather than rely on a summary.

Glass alone often isn’t enough for curtain wall systems on west and south elevations. External solar shading systems cut the load before it reaches the glass, and they can reduce the glazing performance you need to buy.

Wind and Dust

Wind loads on tall façades are set by the structural parts of the code (SBC 301), the building height and its exposure. In Riyadh and across the central plateau, pressure is only half the problem. Fine sand abrades finishes and clogs weep holes. A cavity that can’t drain will hold dust and, after a rare heavy rain, hold mud.

Ask where maintenance access for the curtain wall systems will come from. A façade you can’t reach with a cradle or a building maintenance unit will not stay clean.

Coastal Salt and Humidity

Jeddah, Dammam, Jubail and Yanbu sit in a very different environment from Riyadh. Salt-laden humidity attacks fixings and anchors as well as the cut edges of coated aluminum, so a spec that’s fine inland can corrode in a few years on the Red Sea or Gulf coast.

For exposed steel and stainless parts, grade matters. Our comparison of 304 and 316 stainless steel explains why 316 is the usual coastal choice. For the frame itself, coating quality and pre-treatment decide how long the color lasts, and the architectural powder coating guide shows what to ask for.

Thermal Movement

Aluminum expands about 0.023 mm per meter for every degree Celsius. A 4 m mullion that swings through 60 °C between a cool winter night and a hot summer afternoon grows by about 5.5 mm. That’s small, but a rigid joint can’t absorb it and will crack seals or rattle. The anchors and the slip joints between sections are there to let the frame breathe.

Performance Testing: What to Ask For

Curtain wall systems can look perfect and still leak. Testing is how you find out before the building is occupied. The usual sequence for a mock-up includes:

• Air infiltration, tested to ASTM E283
• Static water penetration, tested to ASTM E331
• Dynamic water penetration, tested to AAMA 501.1, which uses a wind-generating rig and sprays water onto the face
• Structural performance under wind load, tested to ASTM E330
• Building movement, tested to AAMA 501.4, which simulates floor-to-floor drift during sway
• Thermal cycling, tested to AAMA 501.5

European specifications typically reference EN 13830, the product standard for curtain walling, which classifies air permeability, watertightness and wind resistance.

Specifications on Saudi projects can cite ASTM, AAMA or EN methods, and which ones apply is written in the consultant’s documents, not here. What you can do is ask each shortlisted fabricator which reports exist for the system they propose and which tests are planned for your project mock-up. A clear answer tells you a lot. A vague one tells you more.

Fire Safety at the Slab Edge

There’s a gap between the edge of each floor slab and the back of the curtain wall. Left open, it’s a chimney.

The International Firestop Council explains why this gap matters with a worked example: a square building about 61 m on each side with a 75 mm gap leaves roughly 18 m² of open area per floor, through which flame and smoke can reach the floor above. Multiply that by the number of floors and the risk is clear.

Mineral wool packed tightly into the gap is the standard answer, tested to ASTM E2307 for perimeter fire barrier systems. There’s a catch. If the spandrel panel fails or falls away in a fire, the insulation behind it can fall too, so the spandrel’s fixing and backing are part of the fire design. Mullions and anchors also need protecting.

In Saudi Arabia, fire provisions sit in SBC 801 and in any civil defense requirements that apply to your project. Raise perimeter fire containment with your fire consultant at concept stage, not at shop-drawing stage, when changes get expensive.

Buying Curtain Wall Systems in Saudi Arabia

This is the section for people about to request prices. If you’d rather settle scope first, the facade and glazing service page lists what Rounuq Almsar’s factory covers.

Start With the Right System Type

A KFUPM-indexed study in the journal Structural Survey looked at curtain wall types used in Saudi building construction and ranked them against performance and cost criteria. Published in 2014 for medium to high-rise buildings, it ranked precast concrete curtain walls first and prefabricated brick panels second. The takeaway: “curtain wall systems” covers more than glass, and the best choice depends on how you weigh cost, maintenance and appearance.

For glass-and-aluminum curtain wall systems, that weighing is your brief.

What to Send With a Quotation Request

Quotes for curtain wall systems come back faster and closer to final when the inputs are complete.

Table 2: Inputs a fabricator needs

Cost Factors in SAR

We won’t quote a price per square meter here. It would be wrong for most projects, and anyone who gives you one without drawings is guessing. What decides the number in Saudi riyals is more useful to know:

• Glass performance level and thickness
• Mullion depth and aluminum weight, which rise with wind load and span
• Assembly method, since unitized shifts cost from site labor to factory work and logistics
• Finish and coating system
• Fire-rated spandrel and perimeter containment
• Access equipment, crane time and installation height
• Testing, mock-up and engineering fees
• Freight and site storage

Also ask whether a quotation includes VAT. Saudi Arabia charges VAT at 15%, and two quotes can look 15% apart only because one included it.

How a Typical Project Runs

The order rarely changes: shop drawings and calculations, consultant approval, mock-up and testing, fabrication, delivery, installation, and handover with a maintenance manual. Most delays start at the first step, when drawings are incomplete. Our list of common architectural metalwork mistakes covers the ones we see most often, from missing tolerances to unclear scope.

Design Choices That Work Alongside Curtain Wall Systems

Few modern elevations are all glass. Many Saudi façades pair curtain wall systems with metal layers for shading and character. Perforated metal facade panels can sit in front of glazing to cut glare and heat, and custom skylights bring light through the roof where a wall can’t.

Pay close attention to transitions. The point where glass meets cladding, a canopy or a roof is where most water and air leaks begin, so those junctions deserve detail drawings of their own.

Frequently Asked Questions

What are curtain wall systems made of?

Most are aluminum framing with glass or opaque infill panels. The frame includes mullions, transoms, gaskets, thermal breaks and anchors. Insulation sits behind opaque panels, and mineral wool fire barriers fill the slab-edge gap.

Are curtain wall systems structural?

They aren’t part of the building’s main structure. They carry their own weight and the wind loads, then transfer both to the floor slabs through anchors. The concrete or steel frame carries everything else.

What’s the difference between curtain wall systems and a window wall?

A curtain wall passes in front of the slab edge and runs continuously over several floors. A window wall sits between slabs, one story at a time. Curtain wall gives a continuous glass skin; window wall is common in residential towers.

Should I choose stick-built or unitized curtain wall systems?

Stick-built suits lower buildings, irregular plans and short lead times. Unitized suits tall, repetitive elevations and fast-track sites because more work happens in a factory. Confirm with your fabricator which methods they can actually deliver.

How do curtain wall systems cope with Saudi heat?

Through glass selection and shading. Low-SHGC coated glass, thermal breaks and external shading reduce heat gain, while movement joints absorb expansion. Check the energy requirements in SBC 601 for your building type and climate zone.

Which tests should curtain wall systems pass?

Common tests cover air leakage, static and dynamic water penetration, wind-load structural strength, building movement and thermal cycling, using ASTM, AAMA or EN methods. Your project specification names the ones that apply.

What affects the cost of curtain wall systems in SAR?

Glass performance, mullion depth, assembly method, finish, fire-rated spandrels, installation access, testing and freight. Prices without drawings are guesses. Check whether a quotation includes 15% VAT.

What should I send to get a quotation?

Send elevations, floor heights, wind design data, glass targets, location, finish, fire requirements, access method, test requirements and target dates. The more complete the package, the closer the first price will be to the final one.

How Rounuq Almsar Can Help

Rounuq Almsar is an architectural metalwork factory in Riyadh. Its facade and glazing solutions cover curtain wall systems alongside structural glazing, skylights, aluminum cladding and perforated panels, and the team works with architects and consultants on design intent.

Every project is different, so the assembly method, scope and testing for yours are confirmed in a technical review rather than assumed. If you have drawings, send them through the contact page and ask for a review of your facade and glazing scope.