What’s the Difference Between a Three- and Four-Season Sunroom?

What's the Difference Between a Three- and Four-Season Sunroom?When it comes to sunrooms, there seems to be nearly as many varieties as there are days in the week. Conservatories, solariums, garden rooms, porch enclosures, and screen rooms are all designed to create an indoor space that provides expansive views and lots of light, and each has at least one feature that differentiates it from the others. Generally speaking, however, all of these styles can be separated into two categories: three-season and four-season sunrooms. But what’s the difference?

The answer is one season, namely winter. Three-season sunrooms are designed to be used when outside temperatures are mild. That’s because they’re not heated or cooled by a home’s HVAC unit. Although they often have their own system of climate control such as wall-mounted air-conditioners or fireplaces, interior temperatures will fluctuate far more in a three-season sunroom than throughout the rest of the home. As such, they are better characterized as enclosures rather than home extensions.

Four-season sunrooms on the other hand are fully climate controlled, being heated and cooled by the same system that serves the rest of the house. Because of this, they are included in a home’s overall square footage, as opposed to three-season sunrooms, which are not. A well-constructed four-season sunroom will provide a comfortable environment all year round, making it a great choice for homeowners in harsher climates who want to use their sunroom for holiday entertaining and family gatherings.

There are structural differences between three- and four-season sunrooms as well. The windows in a three-season room are not intended to provide the same thermal performance and energy efficiency as those in a four-season room. The insulation in three-season sunrooms is also less substantial than in four-season rooms. Finally, in terms of their overall design, four-season sunrooms are more fully integrated into the rest of the home. They are often entered though French doors or an open threshold, the flooring is comparable in quality to the flooring in the rest of the house, and the roof is usually shingled or tiled to reflect the profile of the main roof. In contrast, a three-season sunroom is often separated from the main building by an exterior wall and is entered though a former back door.

At Pacific Patio, we have been providing our San Diego, CA, customers with custom-made three- and four-season sunrooms since opening our doors in 1989. If you’re interested in expanding the living space at your residence, contact us today and schedule a no-obligation design consultation.