Can a sunroom be included in the gross living area of a home?

I was asked by a real estate agent recently whether a sunroom could be included in the gross living area of a home, and after thinking about it I decided it was a very timely question, so I decided to share it with you. As you may recall I recently wrote about how the Birmingham Multiple Listing Service will be requiring accurate square footage on their listings come May 1, 2014. Deciding what areas can and cannot be included in the heated and cooled gross living area (GLA) is very important and I thought this example might help agents understand how to look at these areas. If you incorrectly add areas to the GLA that you should not, you can get inaccurate price per square foot calculations and incorrectly price the home. Let’s take a look at what goes into deciding what can be included in the heated and cooled gross living area.

One of the first things to look for is whether the sunroom is heated and cooled by a separate unit than the rest of the house. If it is then the room may have been added on after the original construction of the home. This is not necessarily a bad thing but the room may have been built as an enclosed porch rather than an extension of the main residence. This type of room typically has as one of its walls the exterior wall of the house, and you access the room through the back door of the house. One other feature is that the construction quality may be less than that of the main structure. You will be given credit for the room, however it will be to a lesser degree than the main residence, and this square footage should not be included with the overall GLA but it can  be listed separately.

In contrast to the type of room described above the sunroom that is made a part of the home so that it is heated and cooled by the heating and cooling system that services the rest of the house will typically be included in the overall GLA. This criteria however is not the only thing that should be considered. There may be a wall separating the room from the adjacent living area but the design will be more pleasing and the level of quality will be identical to the other parts of the house. Sometimes french doors are used to separate the living spaces while other times there may be a wall with a larger than typical cased opening and the floor plan flows well. There are no hard and fast rules but the main characteristics that should be present are the same level of quality between the two areas, good functionality, and heated and cooled with something more than a window or wall unit.

Take a look at some examples of sunrooms that I have looked at recently. The first picture is of a small garden home with an add-on sunroom.

sunroom that cannot be included in gross living area

While it cannot be seen in this picture, the room had a wall unit for heating and cooling. In addition, the floor is stained concrete and the quality is not at the same level as the rest of the home, so it cannot be included in gross living area. As I noted previously, this room will be included and given credit but not at the same level as the main house, because its construction quality is not as good.

This next image shows a higher quality construction home, however that is not a determining factor. What is more important than the quality is the degree to which the room has been built to blend in with the rest of the house.

sunroom that can be added to gross living area

The room is heated and cooled by the same unit as the main house, is of similar construction quality, and has a good floor plan flow from the main house to the sunroom. Its roof has been tied into the roof line of the rest of the house, unlike the previous example, which had a flat roof. In this scenario it should be included in the total GLA of the home.

I hope my explanation and the pictures I’ve included help you to understand when a sunroom should be included in the GLA. If you have any questions leave me a comment below.

If you found value in this post or in my blog you can subscribe by email or RSS feed. Thanks for visiting.




  1. Hi, I am looking for purchase a home which has a sunroom with a separate wall heating unit from the house. The orginal sqft is 1950 and with sunroom it is 2250. The sunroom is built with the same roofline as the original home so I believe it used to be a porch with ceiling fan and lighting. The floor is still the original concrete. Access is from a frenchdoor in the back of the house. Would this extra 300 sqft be including as GLA? If not, how much credit should I put on it?

    • I would probably need to see the interior to determine the level of finish, however, if the flooring is concrete this may give an indication that the quality is below that of the main residence. Based on this information I would probably not include it in the main residence gross living area, however, it would most likely contribute to value. This amount would depend on what the sales indicate so it is not a fixed amount or percentage of the main residence. The dollar per square foot adjustment for the 300 sf would probably be less than what is used for the main residence.

  2. Pierce Blitch, III says

    I have a “solarium” attached to the house. It is a true solarium with 2 exterior walls that are made up of only glass panels separated by powder coated metal brackets. The ceiling is the same glass panels 24″x36″ and the roof has a 4 in 12 slope out to the section that joins with the back side vertical wall. The last panel of the roof portion is curved to meet the rear vertical wall. There is a through the wall hotel type heat pump on a separate wall mounted thermostat for this room only. The entrance from the house is a 36″ case opening. The floor is 16″ ceramic tiles. It is used as an additional living space by the owners. The contract with the builder for labor and materials for this 15.8’x16.2′ room was $15,462 in 2012. I checked, they did get a building permit. Based on the quality, floor finish, access, and HVAC, I am inclined to include it as GLA in this case. Your thoughts please. Thanks in advance.

    • I think this could possibly be one of those gray areas, however, considering that it has a permanent heating and cooling source that is self-regulating I believe that you would not be wrong to include it. If it is the same or near the same quality as the rest of the house then that would be even more reason to include it. Sometimes the quality of these types of rooms vary and those at the lower end should not be included, however the better quality ones should.

      • Thank you so much for the quick reply Tom. With the current craziness in the real estate market, I just have to bid more and take the chance that the appraisal is not too far away from my bidding price. Will consider the extra 300 Sqft value at less than half (35-45%) of the local market price per sqft for similar houses. Is that a good way to estimate the appraisal value? Thank you again Tom. Really appreciate it.

        • There is no rule of thumb like the 35-45% you mention. It really depends on how buyers react to it and how much they are willing to pay for it. You can look at other similar sales that do not have the feature and see how different the price is.

  3. Kevin Miller says

    Slightly different topic. What if a house has conventional HVAC for the first floor and the finished second floor is a large open room only heated by a gas stove. Is that GLA?

    • If the appraisal is done as-is then yes the flooring will be considered into the value. If your home is worth enough to get the amount of money you want to borrow I would not worry about it but of course, if it is not then you may want to take care of it.

  4. Elizabeth Rivera says

    So I purchased a home back in 2001 (FHA) The appraisal shows a total of 4 rooms ( 2 bed, 1 living 1 Florida room. On the appraisal the Florida room shows it to be GLA. Now 2020 I got my home appraised and they will not include it as GLA. The appraiser says that due to new FHA guidelines. It can’t be included. Back then it was and now I am having problems because the appraisal in coming in lower. Because they say the home is 630 sq ft. instead of 901 sq ft. This is very frustrating and not fair. Please advise if there is anything I can do?

    • I do FHA appraisals but I am not familiar with the new guidelines that they mentioned. You can ask them to provide you with a copy of the FHA guidebook pertaining to this. If anything I would think that it would be because of ANSI guidelines which pertain to how to classify certain living areas and what can be classified as gross living area. It is also possible that the appraiser than included it before should not have.

  5. doris mattson says

    I am buying a house with a covered porch that has had the ceilings and floors insulated and a split heat/cool system, it is screened in with plastic type pull or down windows (no glass). would it be included in sf of house?

    • It sounds like it has a lot of the traits of finished area, however, you say it is screened it so I’m not sure about that. In order for it to be included it should look as much like the rest of the home in terms of walls, degree of finish, etc.

  6. April Jamison says

    Put in an offer partially based on comparing square footage listed on the listing to other houses of same square footage (comps provided by realtor). Now I find that the screened in porch is counted in the square footage making my comparisons (of price per square foot) incorrect. Screened porch isn’t heated, has a cement floor and has a flat room Not integrated to the home’s roof. I didn’t think this was counted in the square footage. Will the appraiser catch this, so I may be able to get the price adjusted down to account for the lower square footage (about 260 sq ft)

    • Yes, April, the appraiser should catch that and not include it in the total gross living area. This could result in the appraisal being lower than the contract and a good opportunity to negotiate the price down. I would definitely point out that the price was based on the larger square footage and since it should not have been then the price should be lower. Good luck.

  7. Vernese Gunter says

    Thanks so much for posting the many questions and answers regarding sunroom additions. You are very knowledgeable.

    • Thanks, glad it is helpful.

      • Lisa Wolff says


        • If the quality of construction is similar and the access provides good functionality it should help. The only other thing that might concern me is whether the HVAC is sufficient to handle the additional square footage, however, if it is sufficient then I would include it in the overall gross living area.

    • Debbie Shaw says

      So glad I found your article. A permitted and on a concrete foundation sun room like your picture #1, with access via a sliding door. Obvious add on, well built however, your article confirmed what I was thinking, that it is not part of the gla. Although it was fun going back and forth between the real estate agent on this . Thanks for the article, I saved it to refer back to it.

  8. Steve Desper says

    According to the guidelines concerning AC… Suppose two houses are build and decorated exactly alike, side by side. Both houses have sun rooms that are part of the original structure. Each house is 2000 sq ft. Each sun room is 350 sq ft. One house has central AC and the sun room has a separate AC unit. The second house’s owner prefers natural cooling from cross-ventilation throughout the entire house and did not install any AC. According to the ANSI guidelines, one house is 2000 sq ft and the other is 2350 sq ft OR the house without AC has NO square footage. So the question is, if the second house should install an AC unit in the wall of the sun room, does that make the area of the second house 350 sq ft., or 2000 sq. ft., or 2350 sq ft.?

    • Since the sunroom is not too large it’s quite possible that the existing HVAC system is adequate to heat and cool the new room. If this is the case, and the sunroom is of equal quality and has good access, etc. then I think it should be included in the rest gross living area.

  9. Hi Tom, I am building a Sunroom that will look just like the main part of the house ie. Roof, Siding, eletrical, plumbing, etc.. I am installing what is called a Mini-Split by Mitsubishi ( Definition: It’s a split system heat pump, which means that he compessor and condensing coil are outdoors, and the evaporator coil and blower are indoor. It is ductless. The Condensor unit is the size of a suite case and is placed on a slap outside. Could I include this in the GLA (Gross Living Area)?

    • Mike, I think the biggest deciding factor is how the rooms is tied into the rest of the house. If it is made to look like the rest of the home in terms of quality and design I would say you can include it in the GLA.

  10. Beth Waldner says

    So you have 2 houses with sunrooms that are both heated and insulated and of construction quality similar to the main house. House #1 has baseboard electric heat throughout and in the sunroom. House #2 has a furnace and baseboard electric in the sunroom. Under this scenario you could count the sunroom in the overall square footage in house #1 but not #2. Does not seem fair and thus I question the requirement that the heat source has to be tied into the source for the main house. I understand that that is what is stated in ANSI guidelines but I think if the sunroom has a reliable and permanent heat source it should be counted. Your thoughts?

    • Thanks for the question Beth, I’ll do my best to answer it from an appraiser’s perspective. My belief is that the construction quality of the room is the first thing that should be considered. If the construction quality is there and the room is tied nicely into the rest of the house then I would include the square footage as long as it has an acceptable permanent heating and cooling source. Many times rooms that are not up to this quality will only have a lesser source of heating and cooling. I think this is what ANSI is talking about. I would look at each situation on a case by case basis before making a final decision.

  11. Great post thanks for the info.

  12. Terrie Fuehrer says


    Thanks so much for your information. I have a room similar to the first one it was built on but does have carpeted floors, wall plugs, two doors and under the main roof of the home but the heat and air of the main home is not big enough to handle that room as well. I was wondering if I had the sellers put in one of the free standing a/c units (not window) what range would that add. I know not same as living sq ft but how do I know how much above non-living sq. ft.? If you did like 5% to the cost of non-living sq ft would that make it way over?

    • Thanks Terrie for the question. It is hard to say how much value it adds since every location is different and there is no given percentage to add to the non-living square footage. The best thing to do is bracket the property with sales that don’t have this feature and also with ones that have this or even better and that way you can approximate the value by reconciling in the middle of the sales. Hope this helps.

  13. Nice job, Tom. I think your photos are great to help show how a big difference in quality can make all the difference whether something is considered to be living area or not.

    • I have found the enclosed porch or sun room can be confusing to agents when trying to decide whether to include it in the square footage. This is going to be very important in my area because agents are now required to include accurate square footage in their listings.

  14. David Black says

    Thanks for sharing these comments. I’m convinced a lot of Agents have questions about how to properly cite square footage in their Listings on Greater Alabama MLS. Your information is helpful…

Speak Your Mind


Sign up and get valuable content!

  • Get local real estate market data
  • Learn valuable information from a seasoned appraiser
  • Find out what adds value to your home

I respect your privacy. Your information stays with me.

Call Now Button