How much value will an ADU add to your home?

Most ADU builders will tell you what a casita costs. The question that decides whether to build is what the finished home will be worth, and what the unit will rent for. We answer that before we quote, in writing, from comparable sales near your address. This page shows exactly what you get and walks through a sample built from a sale you can look up.

What the property review delivers

Buildability

What fits on the lot and what construction involves: setbacks, utilities, the realistic project type, and the permit path for your city.

Value

An estimated completed-property value from recent comparable sales within about a mile, with the adjustments spelled out, and the same for the home as it stands today.

Financing

The routes that fit your equity and income, reviewed with Jesus Lopez, a licensed mortgage professional (NMLS #1915703). An inquiry is not a loan application.

The value analysis is part of every property review, not an add-on. It is prepared by Juan M Lopez Solano, listing agent of record on both completed casita sales (ARMLS #6974372 and #6859624, Planet Realty). It is dated and signed, and it says what it is: a market analysis, not an appraisal.

What is in the report

Subject property	Address, parcel number, year built, lot size, living area the assessor counts, and the existing structure (garage, addition, yard).
Current estimated value	What the home would sell for today, as it stands, from the closest recent sales of similar homes.
Proposed project	The project type, approximate unit size, and the scope on the main house if any.
Projected completed value	What the home with the finished unit is likely to sell for, from sales of comparable homes that already have a casita or equivalent space, and the price-per-square-foot range they set.
Comparable sales and adjustments	Each comparable with address, sale date, price, square footage and price per foot, and a plain statement of how it differs from your home: size, condition, lot, the unit itself.
Rental income analysis	A separate section. Market rent for a unit of that size from current listings nearby, gross yield on the build cost, and the lender rules that let the rent count. Kept apart from resale value on purpose.
What this is and is not	A market analysis prepared by the person named on it, with the date. Not an appraisal; a lender orders its own.

A sample, built from a public sale

We use one of our own completed projects for the sample because every figure is on the public record and you can check it. The home was bought before the renovation, finished with a studio casita, and resold. The report below is reconstructed the way we would have written it in February 2025, then compared with what actually happened.

Sample property-value analysis

3802 N 48th Dr, Phoenix, AZ 85031

Prepared by Juan M Lopez Solano · Reconstructed October 7, 2026

1. Subject property

Parcel

APN 107-31-012

Built

1956

Lot

5,996 sq ft

Living area, assessor

1,228 sq ft

Living area, listing

1,588 sq ft

Neighborhood

Maryvale

2. Current value, as it stood

$280,000 ($176 per listed square foot). Recorded purchase before the renovation (public record). Recorded February 18, 2025. An arm's-length purchase is the cleanest possible current-value figure; for a home you already own we use the nearest recent sales of unrenovated homes instead.

3. Proposed project

Renovate the existing garage conversion into a complete studio casita (about 300 sq ft) with private entrance, full kitchen and full bath; renovate the main house (3 bed / 2 bath) to the same standard.

4. Comparable sales

Renovated three-plus-bedroom homes sold within about a mile in the six months before the subject closed, from the MLS-sourced Redfin record. Price per foot is the comparison unit; the note is the adjustment in words.

Address	Sold	Price	Sq ft	$/sq ft	Adjustment
4335 W Monterey Way	Apr 25, 2025	$414,000	1,704	$243	Larger (4 bed / 3 bath); closest in bedroom and bath count.
2640 N 49th Ave	Mar 28, 2025	$400,000	1,522	$263	Similar size; 5 bed / 3 bath.
5313 W Osborn Rd	Apr 3, 2025	$397,000	1,680	$236	Larger; 5 bed / 2 bath; one fewer bath than the subject.
4210 N 48th Dr	Jun 6, 2025	$420,000	1,117	$376	Smaller house on a 0.3-acre lot; full remodel, new roof and A/C. The lot, not the house, drives the price per foot.
5024 W Osborn Rd	May 15, 2025	$455,000	1,702	$267	Fully rebuilt five-suite multigenerational home. Shown for completeness; too different to weight.

The three rows in black are the projection basis. The two in grey are shown so nothing is hidden, and excluded because the lot or the rebuild makes them a different product.

5. Projected completed value

The basis sold at $236 to $263 per square foot. Applied to the 1,588 square feet a buyer walks through once the casita is finished, that is $375,000 to $417,000. A list price near the middle of that range is the recommendation the report would have carried.

6. Rental income, kept separate

A finished studio with its own entrance, kitchen and bath in this area: about $932 to $1,200 a month (September 2026 readings), or $11,184 to $14,400 a year before vacancy and expenses. Phoenix studio and one-bedroom apartment medians (Zumper) and the low end of the casita range builders report. A casita with a private entrance and yard usually rents above an apartment of the same size. Rent is reported on its own because it is a different decision from resale: an owner who keeps the home collects it; a buyer's lender may count most of it toward qualifying (see rental math).

7. What this is and is not

A market analysis prepared by Juan M Lopez Solano on the date shown, from public sale records. It is not an appraisal. An appraisal is ordered by a lender, performed by a state-licensed appraiser, and follows the lender's rules on which square footage counts and how an ADU is credited. Expect the two to differ, and expect the appraisal to govern the loan.

What actually happened

	Projected	Actual
Completed value	$375,000 to $417,000	$399,000, listed May 1, 2025 at $399,000, closed July 15, 2025
Price per listed sq ft	$236 to $263	$251 ($310 on the 1,289 sq ft the appraiser counted)
Against the Maryvale median	Median $221/sq ft (November 2025)	+14% on listed area, +40% on appraised
Days to first contract		39. Sold at the original list price; the first buyer fell out and the home went back under contract within two weeks.

About the $119,000 difference. The $119,000 between the as-is purchase and the resale came from three things at once: the whole-home renovation, the finished casita, and five months of market movement. This analysis does not assign a share to any one of them, and neither should a buyer or a lender. What it shows is the method: comparable sales set the range, and the completed home sold inside it.

Why a value analysis before you build

It tells you which project type to build. If renovated homes near you sell for more per foot than a casita costs to build, new construction pencils; if not, a garage conversion or a family-use plan is the honest answer. The target areas page shows this for every Valley neighborhood.
It sizes the loan. Renovation and construction loans lend against completed value. A written projection with its comps is what the loan officer needs to start.
It sets the exit. Whether you keep the home or sell, you know the number the market will test you against.

What we need from you

The address. The review pulls the parcel record, the city's rules and the comparable sales; a site visit confirms the lot. Both are included in the property review, and the analysis comes back in writing with the preparer's name and the date.

Request my property review

Sources for the sample: Maricopa County Assessor, parcel 107-31-012; Redfin listing and sale record (ARMLS #6859624); Redfin: Maryvale housing market; Zumper: Phoenix rent report. Comparable-sales set from the MLS-sourced Redfin sold export within a 1-mile straight-line radius; some MLS listings are excluded from that export and non-MLS transfers are absent. Financing is discussed with Jesus Lopez, NMLS #1915703; an inquiry is not a loan application.

Request a property review

Find out what your property can hold.

Send the address and your goal. Anthony Alexander Lopez or Juan M Lopez Solano will review zoning, setbacks and utilities and reach out within one business day. No obligation, and no city approval implied: it is our professional read of your lot.

Prefer to talk? (602) 386-6623 · See completed projects