How to Measure a House with ANSI Standards

After April 1, 2022, appraisers completing work for Fannie Mae are required to measure single family properties to ANSI® Z765-2021 standards. This is a way appraisers measure, calculate and report the living area and non-living areas areas of home. ANSI (American National Standards Institute) has been adopted and is now becoming the standardized way to measuring a house.

To calculate living area in accordance to ANSI standards requires an appraiser to measure a property to the nearest inch or tenth of an inch on all sides. The most effective way to measure with this accuracy would be with use of a laser measure. 

Can Tape Measures Be Effective ANSI measurement Tools?

Tape measures as well as measuring wheels are still utilized by many appraisers however the potential for inaccuracies in measurements is more likely due to potential slack in a tape measure or a measuring wheel that does not travel in a straight path. It also becomes more of a challenge when measuring a room that may have a knee wall or a space with an open area (open foyers). Remember that ANSI standards require an accuracy to the nearest inch or  1/10 of an inch. The slightest slack in a tape measure would likely alter the results. While the difference may be nominal, the measurement would technically not be ANSI compliant.

Laser Measuring with ANSI Accuracy

A laser measure is only as good as the operator utilizing it. While that can be said with tape and wheel measuring, with weather and outside obstacles along properties, it is more challenging to adhere to ANSI utilizing those tools. Even the most basic laser measure offers accuracy to the nearest tenth of an inch or inch. The issue is confirming that your measurement is a true horizontal measurement. Measuring with even a slight angle will lengthen the distance of the value resulting in a skewed living area value.

Certain Leica Disto products have ‘Smart Horizontal Mode’ which utilizes the gyroscope within the laser measure to calculate the angle. Using trigonometry, it provides the base of the triangle (horizonal length) from you and the measurement. This makes measuring incredibly accurate. By utilizing ‘Smart Horizontal Mode’, bouncing the laser off a gutter, siding edge, roof trim or even an awning can provide for a reliable value.

Laser Measures Equipped with ‘Smart Horizontal Mode’

The above are links to amazon for the measure. There is a large price difference from the X3 to the S910 (roughly an $800-$900 difference) and it is due to the added features of the higher end laser measures. I personally recommend the D810 as it provides for rechargable batteries and an LCD/camera combo allowing for ease of hitting the taget. Seeing a red dot is challenging on sunny days. The higher end models have a screen with crosshairs making sunny day measuring a breeze. Check out our review of the D-810 Leica Disto.

What About measuring Angles

For properties that have those odd angles, see what an Angle Ruler can do for you. You should have one on hand for when a property is not just a typical rectangular construction.