Project Delivery
Planning a Steel Building for Future Expansion
Planning for future expansion means designing a pre-engineered building so it can later be extended in length, width or height with minimal disruption, typically by using expandable endwalls, allowing for additional loads, preparing foundations and keeping complete drawings and design records.
Key facts
- Length extension is usually easiest when the endwall is designed as expandable.
- Width extension may require frames designed for added loads or new interior columns.
- Foundations, drainage and utilities should consider the future layout.
- Crane runways and mezzanines need special attention in expansion planning.
- Complete drawings and design records make later extension easier.
Why plan for expansion at the start
Many businesses grow faster than expected. A building designed only for current needs may require major alteration later, while a little planning at the start can make expansion simpler and less disruptive.
Planning does not mean building larger now. It means making choices that keep future options open at modest cost.
Expandable endwalls for length extension
The most common expansion is adding bays to the length of the building. An expandable endwall uses a full rigid frame instead of a lighter post and beam endwall. When the building is extended, the endwall cladding and columns can be removed and the frame becomes an interior frame.
Endwall girts, doors and openings should be planned so they can be relocated or reused. Bracing in the endwall bay may need to move to a new bay.
Width and height expansion
Extending the width usually involves adding a lean-to or a new span beside the existing building. The existing frames may need to carry added loads, such as from a lean-to rafter or from drifting snow at a new valley. These loads should be considered in the original design if expansion is foreseeable.
Increasing height is rarely practical for an existing frame, so the eave height should allow for future racking, cranes or equipment.
Foundations, drainage and services
Foundations along the future expansion side can be designed for the future frame reactions, or space can be left for new foundations. Drainage, utilities and site access should consider the future footprint.
Gutters and downspouts on an expansion wall should be arranged so they can be relocated, and internal valleys created by future spans should be anticipated in the drainage design.
Cranes, mezzanines and records
Crane runways can be extended if the runway beams, columns and rails are aligned and the crane system allows. Mezzanines may be extended if columns and connections are planned for it.
Keep complete as-built drawings, design loads and calculations. When expansion is planned, World Steel can review these records with the project engineer to design new work that integrates with the existing building.
Points to confirm with your engineer
- Direction and scale of likely expansion.
- Expandable endwall frame on the expansion side.
- Loads from future lean-tos or adjacent spans.
- Foundation and drainage provisions for future work.
- Crane runway and mezzanine extension requirements.
- As-built drawings and design records retained.
Frequently Asked Questions
What is an expandable endwall?
An expandable endwall uses a full rigid frame instead of a lighter post and beam system, so when the building is extended, the endwall frame becomes an interior frame without major alteration.
Can a pre-engineered building be widened?
Yes, usually by adding a lean-to or new span. The existing frames and foundations must be checked for added loads, so planning ahead makes this easier.
Can I extend a building from another supplier?
Often yes, if drawings and design information are available or the existing structure can be surveyed. The project engineer reviews the existing building before new work is designed.
Engineering content is general guidance. Every World Steel building is designed by qualified engineers to the code and loads of the project.
