There are three main divisions in the indoor-or-outdoor swimming pool debate; apart from the obvious 'indoor' and 'outdoor' preferences, there is the 'both' camp which wishes to have the benefits of an enclosed pool in cooler weather and an open-air pool on warm, sunny days.
Two families who live near Canada have had swimming pools for a number of years; one family has an open-air pool and their friends have an indoor pool. Both families claim that this is an ideal arrangement because they are happy to share facilities, depending on the weather. You can get more information about swimming pool via https://www.coversinplay.ca/.
The family with the open-air pool uses it most of the year because, even in cold weather, the water and the air just above the surface are warm. The children of the family with the indoor pool prefer to use their friends' open-air pool during the summer months.
It isn't just the weather that is a factor when deciding whether to house the swimming pool or not, permanent buildings are generally subject to planning permission and will require a larger budget than the pool alone. Most popular are brick-built or timber-framed pool-houses; occasionally a pool may be housed in a permanent glass structure.
Retractable glass doors require a solid structure on which they can hang, accommodating an aperture width of up to 7 or 8 meters. They are made of tempered ('unbreakable') safety glass. When open, the breeze can flow through unhindered and sightlines are minimal; when the doors are closed, they are weather-resistant yet allow an uninterrupted view through the sets of frame-less glass doors.