How Are Price per Square Foot Adjustments Made?

 

As a property appraiser, one of the most common questions I hear is:

“The average price per square foot in my neighborhood is $170.
My appraisal only adjusted the gross living area at $50 per square foot. Why wasn’t it adjusted at $170?”

It’s a fair question - and an important one.

The short answer is this:

Price per square foot and square foot adjustments are not the same thing.

Let’s break it down.

Price Per Square Foot Includes Everything

When someone says a home sold for $170 per square foot, that number reflects the total sale price divided by total living area.

But that sale price includes:

• The house
• The lot (site value)
• Garages
• Pools
• Landscaping and patios
• Views
• Remodeling
• Construction quality
• Location within the neighborhood

That $170 figure represents the entire property - not just the additional living area.

So when we adjust for square footage in an appraisal, we’re not applying the full neighborhood average. We’re isolating the value of the additional living space only.

How Appraisers Break It Down

Here’s a simplified example.

A home sells for $200,000.
It has 1,200 square feet of living area.

That equals about $166 per square foot.

But now let’s extract the other components:

• Site value: $50,000
• Golf course view premium: $25,000
• Two-car garage: $20,000
• In-ground pool: $20,000
• Landscaping, patios, fencing: $20,000

That totals $135,000 in non-living-area value.

Now subtract that from the $200,000 sale price.

$200,000 – $135,000 = $65,000

That leaves $65,000 attributable to the house structure itself.

Divide $65,000 by 1,200 square feet:

You get about $54 per square foot.

That’s much closer to the type of adjustment you might see in an appraisal.

The Principle of Diminishing Returns

Another important factor is market expectation.

Let’s say the typical home in a neighborhood is around 1,000 square feet.

If one home is 2,000 square feet, buyers may not pay double the price. Why?

Because neighborhoods have size norms.

As homes get significantly larger than typical market expectations, the price per square foot often decreases.

This concept is called diminishing returns.

As size increases, the incremental value per additional square foot usually declines.

How Appraisers Determine the Right Adjustment

Appraisers don’t guess at square footage adjustments.

We use market-supported methods such as:

• Paired sales analysis (comparing similar homes with different sizes)
• Regression analysis (statistical modeling)
• Market extraction (isolating value components from sales data)

The goal is always the same:

To determine what buyers are actually paying for additional living space in that specific market. Not what the average looks like - but what the data supports.

Think Of It This Way

Square Footage = A Starting Point
Value = What the Market Pays

When reviewing an appraisal, remember:

• Square footage is just one component of value.
• Larger homes don’t automatically command higher per-foot pricing.
• The market - not averages - determines adjustments.

Understanding this difference helps explain why a $170 neighborhood average might translate to a $50 – $60 per square foot living area adjustment.

That adjustment is not a mistake.
It’s market-supported.

What This Means For Your Appraisal

Price per square foot is a useful reference point - but it does not replace a professional appraisal.

An appraisal separates the components of value and applies adjustments based on actual buyer behavior.

If you have questions about your appraisal or how adjustments were calculated, Master Appraisal Services is always happy to explain the process.

 

Need An Appraisal In Phoenix AZ?

If you have additional questions or want to schedule a home appraisal, contact us. We do home appraisals in the Phoenix area including Scottsdale, Chandler, Gilbert, Mesa, San Tan Valley and surrounding areas.

Give us a call to schedule your appraisal.