To Roof or Not to Roof

The decision to build an open-air or enclosed stadium is no longer just a matter of preference — it's a defining choice that shapes a venue’s identity, functionality, and long-term financial performance. As sports franchises and municipalities invest billions into next-generation facilities, the question of roofing has become one of the most costly and complex decisions in the stadium development process.

This is especially true in the wake of Major League Soccer’s shift to a summer-to-spring calendar beginning in 2027. With northern markets now facing regular season matches in November, December, and February, the calculus around roofing has changed dramatically.

So how should owners approach this decision? What are the real trade-offs between canopy, full roof, and retractable systems? And what lessons can we learn from recent stadium projects, both across the U.S. and abroad?

Let’s break it down.

Why Owners Want Operable Roofs — And Why They Rarely Use Them

The National Football League and Major League Baseball have increasingly considered operable roofs when evaluating the roofing decision for their venues. Retractable roofs promise the best of both worlds: the ability to host events in any weather while preserving the open-air experience fans love. But in practice, the flexibility often goes unused.

• NGR Stadium (Houston): The roof last opened only twice during the 2024 season, after remaining closed since 2021
• Globe Life Field (Arlington): In recent seasons the roof has been opened for fewer than 20% of home games
• AT&T Stadium (Dallas): The roof has been opened 30 times across 126 home games — approximately 24% overall
• Lucas Oil Stadium (Indianapolis): Opened in about 29% of 134 total games
• Chase Field (Phoenix): The roof was not fully functional for two years due to a cable issue, preventing the fan favorite pregame ritual of ceremonially opening the roof

Why the disconnect? Operational costs, mechanical complexity, and strict usage thresholds (wind speed and temperature) often outweigh the benefits. In many cases, the retractable roof becomes a rarely used feature with a steep price tag.

Mechanizing a roof adds significant complexity to the structural system and has numerous secondary impacts to other building systems. Retractable roofs also require specialized maintenance long after initial construction is finished. Teams need to consider the long-term cost impacts of keeping trained operators on staff, conducting regular mechanical inspections, and eventually replacing major components.

The Rise of the Canopy: Cost-Effective Coverage with Character

For many MLS clubs, the canopy has emerged as the architectural centerpiece of modern stadium design. These structures offer partial weather protection, enhance acoustics, and create a signature visual identity without the cost or complexity of full enclosure.

• Allianz Field (St. Paul): A 360° metal canopy covers 85% of seating, with a PTFE mesh exterior and integrated LED lighting. Designed to cut wind and protect fans from Minnesota’s harsh winters, the stadium may consider additions like warming zones or radiant heat after the club completes its analysis of the new MLS calendar.
• GEODIS Park (Nashville): The largest soccer-specific stadium in the U.S. features a cantilevered canopy that provides 80% seating bowl coverage that provides shade and rain protection while preserving an open-air atmosphere allowing the natural playing surface to thrive.
• Energizer Park (St. Louis): A sleek, acoustically optimized canopy amplifies crowd energy while offering comfort and shade with 80% seating bowl coverage.

Full Enclosure: When Climate and Revenue Demand Certainty

In extreme climates or multipurpose venues, full roof coverage can unlock year-round revenue and operational flexibility.

• U.S. Bank Stadium (Minneapolis): A fixed ETFE roof provides natural light and snow-load resilience, enabling the venue to host NFL games, concerts, and conventions regardless of weather. The stadium design also incorporates 95-foot-tall operable glass door panels that are opened when conditions are favorable.  Without a roof U.S. Bank would never have hosted the Super Bowl or the NCAA Final Four.

Hybrid Innovation: Retractable Pitches and Moveable Fields

Some venues are pushing the boundaries of flexibility not with retractable roofs, but with retractable fields.

• Allegiant Stadium (Las Vegas): Combines full enclosure with a moveable natural grass field tray, one of only two such systems in North America. The solution balances fan comfort in extreme heat with the Raiders’ preference for natural grass.
• Tottenham Hotspur Stadium (London): Features a world-first dividing pitch system with three massive trays that slide beneath the stands to reveal an artificial NFL field. The stadium can convert between soccer and football configurations in under four hours.

Lessons from the Field: What the Data Tells Us

• Retractable roofs are often underutilized. Owners should model realistic usage scenarios before committing to the premium.
• Natural grass playing surface is a growing priority, especially as leagues and players push back against synthetic turf.
• Climate is the most consistent driver of enclosure decisions. In cold or hot markets, full roofs or hybrid systems may be necessary to ensure year-round usability.
• Acoustics matter. Canopies can be engineered to amplify crowd energy, a critical factor in soccer-specific venues.  Traditional and ETFE roofs can also play havoc with concert ready acoustics.
• Construction timelines and lifecycle costs vary widely. Retractable systems can add months to schedules and millions in maintenance over time, significantly increasing a venue’s capital and operating expenditure.

The Path Forward: A Framework for Informed Decision-Making

Before comparing roofing systems, owners should answer one critical question: What is the primary purpose and revenue model of the facility?

From there, five essential criteria should guide the decision:

1. Climate and usage calendar
2. Revenue model and event mix
3. Lifecycle cost (not just construction)
4. Player and fan preferences (including playing surface)
5. Future flexibility and adaptability

Final Word: There’s No One-Size-Fits-All

A canopy that works in San Diego may be inadequate in Minneapolis. A retractable roof that looks great on paper may rarely be used in practice. The key is to approach the roofing decision with clear-eyed analysis, grounded in climate data, operational realities, and long-term ROI.

As the stadium landscape evolves — and as leagues like MLS shift their calendars — owners must future-proof their investments. The roof isn’t just a capstone. It’s a strategic asset that shapes everything from acoustics to revenue to fan experience.