Real Property Appraisals/GLA in garage


I am a RE appraiser in CA with a question. I inspected a two stories residence with a first level built-in garage that has an office and full bathroom area (160 sf) that is accessed through the garage by stairs from the second level. I have consistently not included that area in the GLA of previous work since it is not accessed from the interior of the residence but the garage (typically given value as a guest room with full bathroom). Am I correct? Public records included this office and full bathroom in the GLA and bathroom count, and several appraisals have been completed in the past on the subject with this area included in GLA. I would like to get a second opinion. Thank you.



I followed your explanation up to the point where you wrote: "...accessed thru the garage by stairs from the second level..." Garages are 1st level improvements, so I'm trying to envision this access "..from a second level..." I'm going to give my input anyway, but if I've not understood your explanation, please correct me.

My opinion is that if there is no direct access to this area from the main residence, it shouldn't be included in GLA. This area also needs to be heated and cooled in the same manner as the main house.

You should Google the following: "Square Footage-Method for Calculating: ANSI Z765-2003" This document presents the ANSI standards for measuring a Single-Family Home. You should also Google: "measuring a single-family home", and variations on this description and download other Standards also.

I follow the ANSI Standards and thus would include this as additional, separate living area, not within the GLA of the main house.

BE SURE TO CHECK PERMITS FOR THIS AREA if you are going to include it as any kind of contributory value. Just because a million prior appraisals included it does not mean any of the appraisers checked the permits.

The issues here are that the city/community in which this property is located may require it to be removed if it is discovered. Example is the City of Azusa which states that if an addition does not have a permit, it must be removed. In addition, I understand that many insurance policies exclude unpermitted areas if they suffer a loss.

That's my input on this. Just do the research necessary to support how you include this area in your appraisal.

John C. Carlson
Victorville and Diamond Bar, CA

Real Property Appraisals

All Answers

Answers by Expert:

Ask Experts


John C. Carlson


Any questions regarding commercial and/or residential appraising, appraisals or real estate valuation such as: appraising as a profession, valuation techniques, comparable sales selection & analysis, the new HVCC and how it affects appraisers & Borrowers. Also, questions like: "Why did my appraisal come in low & what can I do about it?" I cannot answer questions about comparable data in areas in which I do not practice. I have expertise in most areas of So. California.


31-years both commercial and residential valuation experience. State of CA Certified General Real Estate Appraiser, licensed to appraise all property types. FHA Approved. Specialized expertise with historic, architectural & luxury residential property valuation. Experienced in industrial building and small commercial property valuation. Experienced Reviewer of appraisal reports and expertise with intensive forensic reviews to uncover fraudulent appraisal reports. Expert Litigation and Expert Witness experience.

Associate Member of the Appraisal Institute. Associate Member of the Certified Fraud Examiners.

Numerous posts to Blogs. Please "Google" "John C. Carlson Real Estate Appraisals" where a list of responses I have made will show up.

Numerous classes by the Appraisal Institute since 1978 in the practice areas in which I specialize

Past/Present Clients
First Republic Bank Wells Fargo Bank California Bank & Trust Preferred Bank Numerous Attorneys.

©2017 All rights reserved.