A real number for your ADU or guest house. Without the back-and-forth.
Answer a few questions about the ADU or guest house you have in mind, and the estimator below will give you a project range based on actual Hochuli ADU projects across the Phoenix metro.
No pressure to schedule. No marketing emails twice a day. Just a starting number you can plan from, so you can stop guessing whether you can actually afford this and start figuring out whether it’s the right move.
i.A cost range tailored to the path, size, and scope you have in mind, not a generic “ADU cost in Phoenix” ballpark.
ii.An estimated monthly payment, if you’d rather think about the project that way.
iii.A saved link you can come back to whenever you’re ready to keep planning.
When you’re ready to talk, you’ll meet Scott and Lorrie Hochuli (pronounced Ha-Cue-Lee), the founders. Lorrie joins about three out of four in-home consultations because the design conversation is where the real work starts. If you want the deeper read on what drives ADU costs in Phoenix, including the choice between detached, attached, and conversion paths, the kitchen scope rules, and the lot conditions that move the math, our ADU Cost in Phoenix page walks through the data, the cost drivers, and the investment tiers in detail.
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Hochuli Design & Remodeling Team
ADU & Guest House Cost Estimator
Answer 8 quick questions and we'll give you a real project range. No fluff, no obligation. Takes about 2 minutes.
Step 1 of 8
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What kind of ADU or guest house are you planning?
The path you choose is the single biggest cost driver. A detached new build, an attached addition, and a garage or interior conversion each carry very different starting costs.
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Detached New Build
A standalone structure separate from the main house. New foundation, new roof, full mechanical and utility runs to the site. The most flexible path and typically the highest total investment.
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Attached Addition
An ADU built as an extension of the main house, sharing at least one wall. Lower utility costs than detached, faster to permit on many lots, and a natural fit for primary or aging-in-place use.
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Garage or Interior Conversion
Converting an existing garage, basement, or part of the main house into a livable unit. Lowest typical investment because the shell already exists, but the existing structure can constrain layout and finish ceiling.
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?
I'm Not Sure Yet
That's exactly what our in-home consultation is for. We'll walk your lot together, talk through what your goals are and what your lot will allow, and help you land on the right path.
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Roughly how big should the ADU be?
A rough range is fine. We'll dial in exact dimensions during design. ADU size is regulated in Phoenix and most surrounding cities, and your lot may have its own constraints we'll work through with you.
📐 XS
Studio (Under 400 sq ft)
A compact single-room layout with kitchen scope and bathroom. The right size for a guest suite, a home office with overnight capability, or a rental targeting solo professionals.
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📐 S
One Bedroom (400-700 sq ft)
A defined bedroom separated from the living and kitchen space. The most common ADU size and the sweet spot for both rental income and aging-parent or adult-child use.
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📐 M
Two Bedroom (700-1,000 sq ft)
Two distinct bedrooms with full kitchen and bathroom. The right size for a small family unit, two-person rental, or guest house meant to feel like a real home rather than an apartment.
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📐 L
Large (Over 1,000 sq ft)
A generously sized unit, often used for multigenerational living, long-term family stays, or premium rental positioning. Approaches the upper end of what most Phoenix-area lots and codes allow.
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I'm Not Sure
No problem. We'll use a one-bedroom size as the basis for the estimate. We'll work out exact dimensions during design and confirm what your lot allows.
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What kind of kitchen are you planning?
The kitchen is one of the biggest swing items in an ADU. Full kitchen, kitchenette, or wet bar each carry different cost, code, and use implications.
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Full Kitchen
A complete kitchen with full-size appliances, dedicated cooking and prep zones, and meaningful storage. Standard for any ADU intended for full-time independent living or long-term rental.
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Kitchenette
A compact cooking area with apartment-scale appliances, a sink, and minimal counter space. The right call for guest suites, short-term use, or where local code limits a full kitchen.
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Wet Bar
A compact prep area with a sink, under-counter fridge, and minimal counter space. Common in guest houses, office ADUs, and units where the main house kitchen is nearby. Easier to permit in many Phoenix jurisdictions than a full kitchen.
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I'm Not Sure Yet
We'll walk through how the space is going to be used and help you land on the right kitchen scope for the people who'll actually live there.
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What kind of bathroom are you planning?
Bathrooms drive plumbing complexity and finish costs. A full bath with a tub reads differently than a three-quarter bath with a walk-in shower, and a half bath changes the math again.
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Full Bath
A complete bathroom with shower, tub, vanity, and toilet. Standard for any ADU built for long-term living. Typically 50-80 square feet.
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Three-Quarter Bath
A walk-in shower, vanity, and toilet, no tub. The most common ADU bathroom configuration. Saves space and cost without compromising daily function.
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Half Bath
A vanity and toilet only. Appropriate for a guest suite or studio paired with another bathroom on the property.
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What do the conditions on your lot look like?
Site conditions are one of the most underestimated cost drivers in an ADU. Long utility runs, sloped terrain, mature trees that need protection, and access challenges for equipment all move the number.
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Simple Site
Flat lot, short utility runs from the main house, clear access for equipment, no mature trees in the work zone. The cleanest and least expensive site condition.
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Moderate Conditions
Some challenges. Longer utility runs, a modest slope, a few trees to work around, or tight access from the street. Common for established Phoenix neighborhoods.
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Complex Site
Significant challenges. Steep grade, very long utility runs, tight access requiring specialty equipment, hardscape removal, or mature trees that require protection plans. Adds meaningful cost.
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I'm Not Sure
We'll walk your lot together during the consultation and tell you exactly what we see.
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What finish level are you planning?
This is one of the biggest cost drivers. Most homeowners find that the right finish level for an ADU depends on who's going to use it and how long they'll be there.
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All-In
Full custom cabinetry, premium natural stone, designer fixtures, integrated technology, and architectural-grade finishes throughout. The Hochuli signature build. Pairs naturally with detached new construction.
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Premium ★ MOST POPULAR
Semi-custom cabinetry, designer tile, upgraded fixtures, and elevated finishes throughout. The right level for an ADU meant to feel like a real home, including most long-term rentals and aging-parent units.
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Essential
Quality semi-custom cabinetry, durable stone, mid-grade fixtures, and clean, well-designed finishes. The right call for a guest house, short-term rental, or any ADU where function carries more weight than statement.
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I'm Not Sure Yet
We'll walk through your plans, look at how the space is going to be used, and help you land on a finish level that fits both the project and your goals.
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How will the ADU primarily be used?
This shapes the design conversation and helps us understand what you're trying to accomplish.
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Family Member (Aging Parent or Adult Child)
A long-term home for a family member. The conversation centers on accessibility, privacy, and how the unit relates to the main house day to day.
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Long-Term Rental
A unit you'll rent on a month-to-month or annual basis. The conversation centers on durability, code compliance, and finish choices that hold up to tenant turnover.
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Short-Term Rental (Airbnb or Vrbo)
A unit you'll rent nightly or weekly to travelers. The conversation centers on design impact for listing photos, durability against high turnover, and amenities that drive review ratings.
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Home Office or Guest Suite
A workspace during the week, a guest space for visiting family on the weekends. The conversation centers on flow, quiet, and how the space transitions between uses.
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Combination of Uses
The unit will flex across more than one of these over time. Common, and worth designing for explicitly so the space holds up to changing use.
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When are you looking to start your ADU project?
This helps us understand urgency and make sure we can plan our schedule around your goals.
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Within the Next 30 Days
You're ready to move quickly. We'll prioritize your consultation and get you on the design schedule.
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Within a Few Months
You have time to plan properly, which usually leads to better outcomes on an ADU. We'd love to get you on our calendar.
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Just Researching Right Now
You're doing your homework, which is smart. Zero pressure. We'll send you your estimate and be here when you're ready to take the next step.
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Your Estimate Is Ready
$250,000 – $370,000
Enter your info below to unlock your personalized project range
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We'll also reach out to answer questions and schedule next steps.
Your ADU or Guest House Estimate
Based on your selections. Actual costs vary by scope, site conditions, lot conditions, and material choices.
Estimated Monthly Payment
Based on 120-month financing at 6.99%–14.99% APR via Acorn Finance
Financing illustration only. Monthly payment estimates are for informational purposes and do not represent a financing offer or guarantee of loan availability. Actual rate, term, and approval are determined solely by Acorn Finance's lending partners based on your credit profile and other factors. APRs on loans through Acorn Finance range from 4.99% to 35.99% with terms from 2 to 12 years. Loans up to $100,000 available to qualified borrowers.
Learn more at acornfinance.com →
About Your Estimate
This range reflects your project selections and is based on real Hochuli ADU projects completed in the Phoenix metro area. ADU costs vary widely based on the path you choose (detached, attached, or conversion), the size, the kitchen and bathroom scope, lot conditions, and finish level. This is a general planning tool, not a quote or contract. Actual project costs are determined after a thorough in-home consultation, design development, and final material selections. Hochuli Design & Remodeling Team provides firm, fixed-price contracts. You'll know exactly what you're paying before a single nail is driven.
Ready to Make It Real?
Whether it's a phone call to answer more questions, or if you've made up your mind and you're ready to get started planning; we're here to guide you through the process.
Save or share this link to come back to your estimate any time.
What Happens Next
Getting an estimate is easy. Getting the right plan is where most ADU projects fall apart.
An ADU involves more decisions than most homeowners expect. Whether you’re building detached, building attached, or converting existing space, each path carries its own structural choices, utility runs, lot considerations, and design tie-ins. Without a plan that holds all of those decisions together, even thoughtful homeowners end up with an ADU that’s close to what they pictured but never quite right.
A unit that feels disconnected from the main house. A layout that fights the lot instead of working with it. Scope that grew without anyone catching it in time.
That’s where the planning conversation matters.
Here’s how we make sure your ADU starts the right way:
1
We walk through your estimate and your vision
We sit down with you in person or by phone to talk through what you selected and the picture you have in your head of how this ADU should look, function, and relate to your main house when it’s finished. We make sure the new space feels like an intentional part of your property, not a separate project parked next to it.
2
We align your goals with your investment
We talk through the choices that drive the overall investment and how each one connects to what you’re trying to accomplish. You walk out with a clear understanding of what matters most, where your money has the most impact, and how to phase or prioritize the work.
3
You walk away with clarity on your next step
Whether you decide to move forward with us or take time to think things through, you’ll know what it takes to build the ADU you want and how to get there without losing the thread along the way.
Every Hochuli project is fixed price, fixed contract, with everything in writing before a nail is driven. You’ll know exactly what you’re paying for before construction starts, even on a project that involves new foundation work, a new utility plan, and tying into the home you already live in.
If you want to get this right the first time, this is your next step.
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