Description
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.
Our gazebo arrived completely intact and damage free. We had a crew of 4 experienced carpenters install our 12 x 20 gazebo in 1 day. Everything fit together perfectly and looks absolutely beautiful. We couldn’t be happier with the product or the craftmanship of all the components. Our main carpenter has installed other gazebos for clients and said this was the best built by far. We are thrilled with the product and have enjoyed our time in our spa inside the gazebo. We’ll take pictures when the weather is nicer. The gazebo sits beautifully on our very large deck overlooking our pool. It’s a shame our pool is closed for the season and our deck looks empty except for the spa. Thanks for all your assistance in acquiring your product and assuring our delivery. We are very happy customers!
I just wanted to let you know that my gazebo arrived about 2 weeks ago. I put it together this past Friday which took about 8 hour to complete. The hardest part about the install was drilling into the concrete to anchor it. The rest of the installation was very easy. Thanks for the quick turnaround on my order!
We got this for our “party pad” and could not be happier! Overall quality is great for the price, especially when you look at other products on the market. My brother in law and boss are already looking at purchasing because of the quality and experience we had. Took 2 days to put together and it is helpful to have at least 3 adults to get the roof on, but it was well worth the time and we are already using it. We built a 8 ft table to put under it just to give you an idea of size.
Hey Guys, What great service! The gazebo was delivered this past Friday. Looking forward to getting it put together and put it to good use. Again, Thank You for the great service. Looking forward to doing business with you again in the future.
My wife and I love the outdoors and wanted to fix up our back yard, this gazebo was a great addition, we now can use our back yard more and have friends over.
Absolutely beautiful product with exceptional customer service! When calling with questions or concerns this company could not have been more helpful! Product is outstandingly beautiful and well built. We were told they have the best customer service in the industry. They did not disappoint! Added so much beauty to our backyard and to our home.
This gazebo is a beautiful addition to our backyard and was an awesome family project last summer. The Ultrawood is gorgeous and the customer service from Westview was excellent. We had some damaged pieces caused by the forklift that were replaced without any issues. Assembly took three days for us. We were happy with the kit and precut pieces that enabled novices to learn on the job. I recommend the gazebo as a beautiful hobby space, and Westview for the great service!
Customer service was extremely helpful from beginning to end. When we ran into a snag with installation, Westview patiently walked us through the steps on the phone, isolated the problem and was able to help us resolve it. Their professionalism and craftsmanship is unmatched!
My wife and I purchased the Colorado 12×20 gazebo as a shelter around our new hot tub. At first we were concerned about the price and the fact that we did not have any construction experience. When we unpacked all of the parts and pieces it was overwhelming and we wondered if we’d made a big mistake by greatly overestimating our abilities. Once the 1st corner was standing and we started putting together other sections, the building started taking shape quicker than we thought. As we studied the directions we were able the figure out how just the two of us could do the next installation steps. Now that the building is finished, we are very pleased with the outcome, the beautiful appearance and strength of the building. As we sit in the hot tube looking up through the skylight, we are both proud of the finished product and find the building worth every penny and all the hard work. You can do this.
Instructions for putting it together were okay, the Roof was the most difficult to put up, definitely easier with more people. I mounted mine to my wood deck it took me 2 days, first day the Walls and Door, the second day the Roof and attaching to the deck. Spent a lot of time looking at instructions and making sure I got it right the first time, so it could probably have been done in a day if need be. Overall I am pretty happy with this Spa Gazebo.
James, attached are two photos of the gazebo. I have been enjoying it very much! Do these photos work? I can get more possibly tomorrow or in a day or two. It ready looks great in my back yard! Thanks!
The gazebo was shipped very fast. 1-2 weeks. Was packed extremely well. No one could believe a 12X20 gazebo came in the shipping crate. Assembly was very straight forward. Just needed to pay attention and use common sense. Anyone that has seen, it Raves about it.
We are really happy with our Colorado 12×20 gazebo. My husband and son put the building up in about 9 hours. We are very social people and enjoy using our backyard to entertain friends and family. This gives us the opportunity to do it year round. Love it and recommend Westview Manufacturing.
This spa enclosure far exceeded our expectations. The gazebo is very well built. The Ultrawood is very nice and not fake looking. The gazebo actually goes really well with the Trex Decking we installed last summer.
The finish is beautiful and cleans easily. Still looks brand new after months.
The Colorado 12×20 is very versatile. We’ve used it for dinners, reading, parties, and even as a home office.
We checked several brands before choosing Westview and we’re glad we did. So happy with our Colorado 12×20.
The structure is heavy and solid—exactly what we wanted. We use our Colorado 12×20 as a boys recreation room for our three teenage sons.
Great product. Everything about it feels well-designed and high quality.
The Colorado 12×20 is perfect for hosting friends. We use it all the time in the summer.
Took two afternoons to build the Colorado 12×20, but nothing was frustrating. Everything fit perfectly.
The Colorado 12×2 Gazebo gives our yard a resort-like feel.