Colorado 12x20

The Largest Colorado Gazebo: Built for Swim Spas, Oversized Hot Tubs, and Outdoor Living

The Colorado 12×20 is the flagship of the Colorado collection — and for good reason. With interior dimensions of 132 5/8″ x 227 7/8″ (roughly 11 feet by 19 feet of usable floor space), this is a large enclosed gazebo with enough room to house a full-size swim spa, a party-size hot tub with a complete lounge area, or a combination entertainment room with spa, seating, a mounted television, and a sound system. This is not just a hot tub shelter. It is a year-round outdoor living space.

If you own a swim spa or are planning to purchase one, the Colorado 12×20 is purpose-built for that use case. Most swim spas range from 12 to 16 feet in length and 7 to 8 feet in width. The 12×20 provides the interior clearance needed to fit the spa itself along with walking space around all sides for safe entry and exit, maintenance access, and room for a small seating area at one end. Protecting your swim spa investment with a fully enclosed structure reduces heat loss, lowers energy costs, keeps debris and leaves out of the water, and allows you to swim and exercise year-round regardless of outside conditions.

 Ultrawood Composite: The Last Gazebo You Will Ever Buy

Like every model in the Colorado line, the 12×20 is constructed from Ultrawood composite. This is not a temporary structure or a disposable big-box store gazebo that lasts two or three seasons before the wood rots, the fabric tears, or the frame rusts. Ultrawood is an engineered composite material designed for permanent outdoor use. It does not absorb moisture, crack, splinter, fade, or attract insects. And it requires zero maintenance — no staining, no sealing, no painting, no sanding. Ever.

The coastal gray exterior with gray driftwood trim on windows and doors gives the Colorado 12×20 a refined, modern look that integrates naturally with a wide range of home styles. Whether your property is a lakefront cabin, a suburban family home, or a rural retreat, this enclosed outdoor structure looks intentional and premium.

Duraflex Roof: Engineered for Snow, Rain, and Wind

The Duraflex PC roof on the Colorado 12×20 carries the same 35 lb. per square foot snow load rating, or 40 lbs. per square foot with the bracket upgrade, as the rest of the collection, which is critical at this larger roof span. A wider structure means more total surface area catching snow and rain, so engineering matters. The hardtop polycarbonate roof handles it without issue. It is also far quieter during rainstorms than a metal roof, and far more durable than any fabric canopy or soft-top gazebo alternative on the market.

A skylight centered in the roof brings daylight into the interior, which is especially important in a structure this size. Without it, a 12×20 enclosed space could feel dark. With it, the Colorado feels open and inviting. Six aluminum-framed sliding glass windows surround the structure, providing ample ventilation in warm months and a sealed, weatherproof enclosure in cold months. Each window slides smoothly and locks securely.

Practical Considerations for Larger Structures

A structure this size requires a properly prepared foundation. Most Colorado 12×20 buyers install their gazebo on a reinforced concrete pad, which is the best surface for supporting both the weight of the structure and a water-filled swim spa or hot tub. A wood or composite deck, tiled or paver patio also work well as mounting surfaces. Westview’s engineering stamp document is available for customers who need documentation for permit applications or HOA approvals.

Assembly of the 12×20 follows the same pre-assembled panel kit approach as every Colorado model. The panels are larger and heavier at this size, so plan for two to three people and a full day (or a comfortable two-day weekend project). All you need is a power drill, a tape measure, a level, a step ladder, and some wood clamps for holding panels in position while you fasten them. Westview’s detailed instruction manual walks you through each step, and phone support at 1-800-895-1972 is always available.

Transform Your Backyard into a True Outdoor Living Room

The Colorado 12×20 is the model that Westview customers choose when they want to create a destination in their backyard, not just protect a hot tub. Owners have transformed this space into resort-style pool houses with lounge seating and wet bars, private home spas with aromatherapy and ambient lighting, and multi-use outdoor rooms that serve as an entertainment pavilion in summer and an enclosed retreat in winter.

Optional upgrades include screen kits for insect-free warm-weather use, tempered glass for enhanced insulation and safety, and reinforced bracket kit for extreme weather regions. Multiple upgrades can be bundled at a reduced package price. Affirm financing is available at checkout. To discuss whether the 12×20 is the right size for your swim spa or hot tub setup, call the Westview team at 1-800-895-1972 — they are happy to walk you through measurements and options.