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Facade and Curtain Wall Details: The Architect's Role

On most curtain wall projects, the specialist designs the system. The Architect still owns the performance intent and the interfaces.

Curtain walls and complex facades are usually designed in detail by specialist contractors, based on the Architect's design intent. Getting the balance right, enough information to define the design but not so much that it conflicts with the specialist's system, is key.

Design intent drawings

The Architect typically produces:

• Elevations showing panel layouts, mullion grids and materials
• Plans and sections showing facade zones and setting out
• Typical details showing intent at key junctions
• Interface details with adjacent construction
• A performance specification

These define what the facade should look like and how it should perform, without fixing every component.

Performance requirements

Performance specifications commonly cover:

• Structural performance, such as wind loads, usually coordinated with the structural engineer
• Weather tightness, including air and water
• Thermal performance
• Acoustic performance
• Fire performance
• Movement accommodation

The specialist then designs a system to meet them and submits shop drawings and calculations.

Interfaces

The most important Architect drawings are often interfaces, where the facade meets:

• Slab edges and structure
• Roofs and parapets
• Ground level and thresholds
• Other facade systems
• Internal finishes

Show who's responsible for each element at each interface.

Fire at slab edges

Fire stopping between the facade and slab edge is critical. Requirements depend on the code and building type. In England, Approved Document B sets requirements, including restrictions on combustible materials in external walls of certain buildings. In the US, the IBC addresses exterior wall fire performance and perimeter fire barriers. In the UAE, the Fire and Life Safety Code sets facade requirements. Confirm requirements with the fire engineer.

Movement

Facades need to accommodate building movement, such as slab deflection and thermal expansion. The structural engineer usually provides movement values, which the facade specialist designs for.

Reviewing specialist drawings

Coordinate early

Early engagement with facade specialists, where procurement allows, helps resolve technical issues before the design is fixed.

Plan for maintenance and access

Facades need cleaning and maintenance over the building's life. Consider how glazing will be cleaned and replaced, whether building maintenance units or access systems are needed, and how these affect the facade design. Showing these provisions early avoids late changes to roof layouts and facade fixings.

1. 01Design intent drawings
2. 02Performance requirements
3. 03Interfaces
4. 04Fire at slab edges
5. 05Movement
6. 06Reviewing specialist drawings

Mock-ups and testing

Larger facade packages often include visual mock-ups and performance testing. Allow for them in the specification and programme.

Good facade documentation defines what matters and leaves room for specialist expertise, giving the building an envelope that looks right and performs well.

If your team needs extra production capacity for work like this, take a look at our Architectural production services, or tell us about your project.