The Difference Between A Sunroom And A Room Addition

Homeowners who are considering adding a sunroom to their home may have a lot of questions and we here at Custom Sunrooms Richmond would like to help take the confusion out of making this important decision.

For starters, there are distinct differences between putting in a sunroom versus building a room addition even though it may not seem so at first glance. It’s true that a sunroom is a sort of room addition even though they are two very different things.

Room Additions

The most important thing to keep in mind is that a room addition has all of the facets of adding a whole new room to the house. It contains everything you might expect to have in any other room of the home including a heating and cooling system to control the climate inside that space. So if you feel chilly you can turn up the thermostat and have heat blown into the room addition. Same with your air conditioning.

As a result, any room addition must be connected to a central HVAC system if there is one in the home already. This room must be tapped into the central furnace or central cooling that regulates the climate of the rest of your home.

Depending on the intended use of your room addition, you may also want to incorporate plumbing into the space.

Room additions are also characterized by the way you enter and exit the room. You typically won’t find a door leading to the exterior of the house in a room addition. In most instances, the only way you can access your room addition is through an archway or interior doorway leading from a hallway or adjacent room.

The construction of your room addition is also different from a sunroom. With an addition, the work is done on-site, at your home, built in the same manner as the rest of the house. There is little to no pre-fabrication done prior to the contractors’ arrival at your property.

Room additions are the ideal solution to add more space to the home when you need privacy, full amenities, and you don’t require any access to the outside. These spaces are characterized by an extension of the exterior walls and existing roofline of the home.


Adding a sunroom to the home offers a multitude of options as to how you choose to integrate the space to the rest of the dwelling. You can choose to install a three-season sunroom or a four-season sunroom. The delineation between them can be found in how you design the room.

Most three-season sunrooms will not have climate control capabilities, so there is no HVAC unit in the room, nor is the sunroom insulated all that well, so you’re at the mercy of the outside temperatures when you enter the room. This is not the case with four-season sunrooms as these will have some kind of HVAC component, but that heating and cooling apparatus will not be hooked up to the central system that heats and cool the rest of the home.

Four-season sunrooms will often a standalone heating and cooling unit installed and these rooms are usually much better insulated than their three-season counterparts. This makes four-season sunrooms better suited for homes that reside in colder regions of the country. Much like a room addition, a four-season sunroom can be used all year round as opposed to a three-season sunroom which may not be all that comfortable to use in the dead of winter.

One of the biggest differences between a sunroom and a room addition is the amount of glass that is used in the construction of the former. Sunrooms are recognizable by how much glass is incorporated into the manufacturing. Under the International Energy Conservation Code (IECC) any conditioned living space may not be built with more than 40% of glass as part of the walls. Sunrooms do typically contain over 40% glass, giving you the opportunity to see more of the outdoors surrounding your home and your property overall. These expansive views of the outside are among the most popular reasons why homeowners choose these types of dwellings.

In addition, a sunroom is not built on your property from the ground up. Most sunrooms are constructed elsewhere and transported to your location for assembly. They are pre-fabricated structures that are put together at your home and attached to the exterior of the house. This makes for less of a mess around the outside of your house and all around the property, unlike the construction of a whole new room addition.


David Rosenberg: A seasoned political journalist, David's blog posts provide insightful commentary on national politics and policy. His extensive knowledge and unbiased reporting make him a valuable contributor to any news outlet.