9 Home Measurement FAQ’s For Agents

Correct Home Measurement Can Prevent Mistakes

home measurement FAQThis week, while working on appraisals, I had a couple of situations where the real estate agents for two homes I was appraising used the incorrect square footage in their listings. If they would have known the guidelines for home measurement this could have been avoided.

The first situation involved the agent using a square footage that was less than what the house actually had. The house ended up appraising for more than what the contract was for and money was left on the table.

The second situation was just the opposite. The agent used a square footage figure that the owner had given them and it turned out to be more than what the house had. The appraisal value for this home was less than what the contract was for. This was probably due to the fact that the list price was based on how big the house was.

These two examples emphasize the importance of having accurate square footage for real estate listings. While each example had different outcomes both results were based on what the agent had used as the square footage.

I have written previously about the different aspects of getting accurate square footage so if you’d like to dig deeper into that I highly recommend reading my previous posts. Today I thought I would share some FAQs I’ve been asked over the years to help clarify some confusion about home measurement.

If you have any additional questions please let me know by adding a comment below.

Top Home Measurement Questions

What measuring standards do you use- There are various measurement standards available, however, I use the ANSI Z765 standard. It is a widely accepted standard that makes it possible to obtain accurate and reproducible measurements of square footage in single-family homes.

The FAQs below are answered based on the ANSI standard.

Can staircases be included?- Staircases can be included in the square footage calculations. The area of the stairs and landing are included in the square footage of the floor they are coming from. The only area not included would be an opening where there were no stairs.

Can a two-story foyer be included?- Two story foyers are not included in the living area of the second floor because they cannot be used or walked on.

Do you measure from the inside or outside- House measurements on the first or main level of a multi-level home are taken from the outside. If a home is a true two story where the second story is the same as the first then measurements for the second level would be the same as the first.

If the second floor is a half story then measurements must be taken from inside. When this is done the estimated wall thickness can be added back to approximate what the exterior measurement would be. I have found that wall thickness is typically around 6 inches.

Can an enclosed porch be included?- It depends on the quality of finish, type of heating and cooling system used, and floor plan layout. Each case is unique. You can read more about this in a previous post I wrote where I go into more detail.

Can my garage apartment be included?- It is possible for garage apartments to be included if they meet certain guidelines. The most important thing to remember is that in order for it to be counted you have to be able to access the apartment from a continuous finished area from the main area of the house.

There are two scenarios where the area would NOT be counted. The first would be where you have to go outside of the main residence to get to the garage apartment such as when it is detached.

The second situation would occur when the garage is attached to the home but you have to go through the unfinished area to get to the finished area. I typically see this when you go into the unfinished garage to get to a staircase that then leads you up to the apartment over the garage.

Can my walkout basement be included in GLA?- Most people understand that basement area is not included in the gross living area of a home. The walkout basement can be a little more confusing. A walkout basement is one where the home is built on a slope and one side of the home is built underground and the other side opens up to the outside.

Because part of the basement is underground it must be included in the basement area and you cannot include it in the gross living area. This area will contribute to the overall value of the home but usually at a lower rate.

Most people think that if the basement area is not included in the gross living area that it is not given value but this not true. All features of a home contribute to value but at different rates.

Can attics be included?- Like basements, attics can be confusing. For an attic room to be included in the gross living area, it must be finished off to the same quality as the rest of the home and the heating and cooling must meet the same guidelines as the enclosed porch.

One feature of attics that present problems are that of the sloped ceiling and wall. There are severalattic floor height requirement criteria that must be met in order for this area to be included. The first criteria is that at least one-half of the finished square footage in that room must have a vertical ceiling height of at least 7 feet and no portion of the finished area that has a height of fewer than 5 feet may be included in the finished square footage.

Can additions be included?- Additions can be included in total gross living area calculations if they meet all of the criteria previously noted. The reason I bring this up is because of a situation that occurred in a past appraisal.

The owners had enclosed a large storage area attached to the back of the house. The only problem was that there was no direct access to the room and you had to go through the back door to the outside and then enter another door to get to this room. It could not be included in the gross living area but it was included in the appraisal and contributed to value.

One thing to keep in mind in situations like this is that if it’s possible to create a doorway or hallway to the living area you should probably go ahead and do this because the cost to do so will probably be less than the additional value you get by being able to include that area in your home’s gross living area.


Knowing the rules for what can and cannot be included in the gross living area of a house can help an agent know more about home measurement. This can help prevent mistakes in your MLS listings that cause appraisal problems. If you need a listing measured feel free to give me a call.

Order Your Floor Plan Sketch Now

If you liked this post subscribe by email (or RSS feed). Thanks for visiting.


  1. Nice work here Tom. I think you hit on some huge points. I also appreciate your honesty that the answers aren’t always straightforward when it comes to attics and basements. It really depends on what is there.

    • Thanks, Ryan. ANSI is a standard but sometimes (not much) you may have to deviate based on the market. When this is the case I think it is very important to make sure you are comparing apples to apples when it comes to square footages and the different levels of the home.

  2. Thank you for the post Tom. What is amazing to me is how often appraisers in my area will say they are measuring to ANSI standards, but then they do not include the stairs. Thank you for making a point of the stairs. Appraisers often get ANSI and AMS confused. The other issue I see is when appraisers get sloppy with rounding to the nearest foot or sometimes even to the nearest half foot, do not cross check through interior at the end. ANSI standards of a 10th foot are are to meet, but I’ve seen tolerance stacking result in measurements that are off by hundreds of square feet.

    • Thanks, Gary. I agree that we should be accurate when it comes to rounding and not round too much as small errors here and there can really add up.

  3. I enjoyed your post Tom! I always do! I’ve run across the same kinds of situations where the appraised value was higher or lower than the contract price due to measurement innacuracies. Thank you for the comprehensive list of answers about how we measure homes. Hiring an appraiser to measure a home is a great idea!

    • Thanks, Jamie. I’m passionate about the accuracy of square footage in the MLS because so many things depend on it. Agents use it to price their listings and we use it in our appraisal reports. Having inaccurate square footage figures also affects statistical data that the MLS provides when they give market report updates to the public. You know the old saying “garbage in, garbage out” right? This is no truer than in housing stats and it makes us no more accurate than Zillow if it’s wrong.


  1. […] 9 Home Measurement FAQ’s For Agents – Birmingham Appraisal Blog […]

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.