A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateTrusted ADU Builders for Pasadena Homeowners
An ADU in Pasadena typically costs between $180,000 and $380,000 depending on whether you’re converting a garage, building detached in the backyard, or adding a JADU inside the existing house footprint. For homeowners exploring nearby options, we also serve as ADU Builders in San Marino. Most projects take 8 to 14 months from first plan to final inspection. If you’ve already been through a remodel that went sideways – missed schedule, price moved at the door, permit board left blank – you know exactly what we’re talking about. Fielding ADU Pasadena, led by Reed Calloway, has been building to The Garrison Standard since 2006, which means the price goes in writing before a single nail is driven, permits get pulled by the book, and every project carries a written one-year guarantee. Call (626) 657-5541 and a live person answers, day or night.
Key Takeaways
- Written price before any work starts. The number you approve on day one is the number on the final invoice. No change orders, no surprises.
- Permitted work, every time. We pull permits in Pasadena and pass inspections. No blank permit board, no “we’ll handle it later.”
- 365-Day Done Right Promise. Every ADU we build is backed in writing for a full year. If something fails, we return and fix it at no charge.
- Background-checked, uniformed crew. You know exactly who is on your property, every day.
- Live person answers 24/7. No voicemail, no callback queue. Call (626) 657-5541 at noon or midnight.
ADU Construction
ADU Construction is the full process of building an accessory dwelling unit on your Pasadena property – from site assessment and design through foundation, framing, mechanical, finishes, and final inspection. It’s not a side project for a general contractor who mostly does kitchens; it’s a specialty that requires understanding Pasadena’s zoning code, setback rules, and the California statewide ADU mandates that override some local restrictions. Fielding ADU Pasadena does this work as our core business, not an add-on. Garage conversions in Pasadena typically run $180,000 to $260,000 before permit fees; detached new construction runs $280,000 to $380,000 depending on size and finish level. We hand you a written price before any work starts, so you know the full number on day one.
Garage conversions
Converting an existing garage is usually the fastest and most cost-effective way to add a legal ADU in Pasadena or through our ADU Builders - Temple City service area. The structure already exists, which saves foundation and framing costs. We handle the entire conversion – insulation, electrical panel upgrades, plumbing runs, egress windows, and the finish work – and we pull the permits so the unit is legal when it’s done.
New construction ADUs
Building from the ground up gives you full control over layout, ceiling height, and orientation on the lot. We work with both conventional stick-built methods using James Hardie siding and with prefab platforms like Abodu and Cover when the lot and budget favor factory-built. The right approach depends on your setback constraints, soil conditions, and how quickly you need the unit finished.
Detached ADU
A Detached ADU is a standalone living unit built in the backyard, fully separate from the primary residence – its own foundation, walls, roof, kitchen, bathroom, and entrance. ADU Builders in Pasadena help homeowners choose a detached unit when they want complete privacy for a tenant, aging parent, or adult child. Reed Calloway has guided dozens of Pasadena homeowners through this decision, and the price range is $280,000 to $380,000 depending on square footage, site prep, and finish level. The written price you approve covers everything – design, engineering, permits, construction, and the one-year written guarantee – before we break ground.
Site constraints in Pasadena
Pasadena lots run tight, and many were subdivided before modern setback rules existed. That means setback variance applications – the city’s written permission to build closer to the property line than the standard rule allows – are a regular part of detached ADU work here. We handle the variance paperwork and represent you at the planning counter.
Prefab vs. conventional build
For a detached unit, we can go conventional stick-built or bring in a modular system from Dvele or Plant Prefab. Prefab can cut on-site construction time significantly, but it requires a lot that can accommodate crane access or panel delivery. We’ll tell you honestly which method fits your property and budget, and the price goes in writing either way.
JADU
A JADU – Junior Accessory Dwelling Unit – is a smaller living unit created within the existing footprint of your house, usually by converting a bedroom, attached garage, or bonus room and adding a kitchenette and separate entrance. California law caps JADUs at 500 square feet. They’re the least expensive path to a legal rental or family unit, and in Pasadena a JADU conversion typically runs $90,000 to $150,000 before permit fees. Fielding ADU Pasadena handles the full conversion, including the required separate entrance, the kitchenette with cooking appliance, and the permit package that makes it legal.
Owner-occupancy rules
JADUs come with one requirement detached ADUs don’t have: the property owner must live on the lot, either in the main house or in the JADU itself. That’s a state rule, not a Pasadena quirk. If you’re planning to rent the main house and live in the JADU, or vice versa, this is the fastest legal path.
Utility sharing
A JADU typically shares the main house’s water, sewer, and electrical service, which is why it costs less than a detached unit. That also means the conversion work has to be coordinated carefully with your existing panel and plumbing. We inspect the service capacity before we finalize the written price, so there’s no surprise upgrade cost mid-project.
ADU Plans
ADU Plans are the architectural drawings and permit documents that Pasadena’s Building & Safety Division requires before any construction can legally begin – site plan, floor plan, elevations, structural calculations, and Title 24 energy compliance. They’re not a formality; they’re the document set that keeps your project legal and insurable. Fielding ADU Pasadena produces permit-ready plan sets as part of every project we build, and the plan phase typically costs $8,000 to $18,000 depending on unit type and site complexity. That cost is included in the written total price we hand you before any work starts, not billed as a separate surprise.
Survey and site plan
Every ADU plan package starts with a property survey and a site plan that shows the existing structures, proposed unit footprint, setbacks, and utility connections. Pasadena requires specific setback dimensions – 4 feet for side and rear yard setbacks for most ADUs under state law – and the site plan has to show compliance in writing. We coordinate the surveyor and the city submittal.
Permit submittal and corrections
Pasadena’s planning department reviews every ADU submittal and nearly always requests corrections on the first pass. That’s normal, not a signal something’s wrong. We handle the resubmittal cycle and track the review status, so you don’t have to learn the city’s comment system or chase a plan checker. The permit is pulled in our name, and the inspections are scheduled by us.
ADU Contractor
An ADU Contractor is the licensed general contractor responsible for building the accessory dwelling unit to the approved plans, managing the subcontractors, pulling permits, scheduling inspections, and standing behind the finished work. In Pasadena, that contractor should be fluent in the city’s ADU ordinance and the state housing laws that preempt local restrictions. Fielding ADU Pasadena has been doing exactly this work since 2006, and our written price policy means the contractor relationship starts with a number you can hold in your hand. A full ADU build in Pasadena – design through final inspection – runs $180,000 to $380,000 depending on scope and finish.
Written price before work starts
Most contractor disputes start with a verbal estimate that drifts. Our policy is different: the price goes in writing before a single nail is driven, every time, with no exceptions. The scope, the materials, the timeline, and the guarantee are all spelled out on paper. The number you approve is the number on the final invoice.
The Garrison Code
We operate by The Garrison Code, and it’s simple enough to write on a job-site whiteboard: show up in the window, price in writing, by the book, leave it clean, stand behind it for a year. Reed Calloway and every crew member on a Fielding ADU Pasadena job works to that standard. The one-year written guarantee is not a verbal promise; it’s a document that says exactly what’s covered and exactly how we make it right.
ADU Design
ADU Design is the phase where the unit’s layout, size, roofline, window placement, and finishes get worked out before plans are drawn – the point where a good designer saves you money by solving problems on paper instead of in the field. Pasadena lots vary enormously: some are flat, some slope toward the Arroyo, some have protected oak trees that constrain the footprint. Fielding ADU Pasadena handles design in-house and with our platform partners, and design work typically costs $6,000 to $15,000 as part of a full build. The design fee is included in the written total, never billed separately.
Matching the unit to the neighborhood
Pasadena has strong design review in some districts, especially in historic neighborhoods like Bungalow Heaven and the Arroyo Seco area. That means the ADU’s exterior – siding material, roof pitch, window style – may need to match the main house. We use James Hardie siding and other materials that satisfy the review board while keeping costs predictable.
Working with prefab platforms
When a prefab ADU makes sense, we work directly with Abodu, Cover, and Dvele on the design side. Their standard models can be modified to fit your lot and your budget, and we integrate their drawings with Pasadena’s permit requirements. The result is a design that’s approved faster and built cleaner than a fully custom plan.
Backyard ADU
A Backyard ADU is a detached accessory dwelling unit built in the rear yard of a Pasadena property – the classic backyard home. We also build these as ADU Builders - Arcadia. It’s the most expensive ADU type and the most flexible: full privacy, no shared walls, and complete control over the floor plan. Backyard ADUs in Pasadena typically run $280,000 to $380,000 before permit fees, depending on square footage, site access, and foundation requirements. Fielding ADU Pasadena builds backyard ADUs as our primary business, and we carry the one-year written guarantee on every one.
Foundation and site work
Pasadena’s soil varies block to block – some areas have expansive clay that moves with the seasons, others sit on stable alluvial deposits. The foundation design has to match the soil report, and that report is part of our pre-construction process. We don’t guess at slab thickness; we engineer it to the lot.
Utility connections
A backyard ADU needs its own sewer lateral, water service, and electrical feed, run from the main house or the street. In older Pasadena neighborhoods, the existing sewer line may be cast iron and decades old, which can add cost. We scope the lines before we finalize the written price, so the underground work is in the number from day one.
Brands We Service
We work with Abodu prefab ADUs regularly, and we know their standard models, their site-prep requirements, and their permit package workflow. Abodu units are factory-built in California and assembled on your Pasadena lot, which cuts on-site construction time compared to a conventional build. We handle the foundation, utility stubs, and city paperwork, then coordinate the installation.
We also build with Cover and Dvele panels when the project calls for a more customized prefab approach. Cover’s panelized system allows design flexibility that a standard module doesn’t, and Dvele builds high-efficiency units that meet strict energy standards. For conventional builds, we use James Hardie fiber cement siding, which holds up to Pasadena’s dry summers and rainy winters without warping or fading. Whether you want a prefab platform or a fully conventional build, we can help you sort the options and put a written price on the table.
Signs You Need a Pro Right Now
- Your contractor stopped returning calls after the deposit. If you’ve paid money and the crew hasn’t shown up in weeks, that’s not a schedule slip – that’s abandonment. A licensed ADU contractor with a written price and a written guarantee doesn’t disappear. Call us and we’ll give you an honest assessment of where your project stands and what it takes to finish it.
- The city posted a stop-work notice on your property. Pasadena Building & Safety posts a red tag when work is being done without a permit or in violation of the approved plans. That stops the project until the violation is corrected, and correcting someone else’s unpermitted work is often harder than starting fresh. We handle permit rescues and can bring the project into compliance.
- Your plans were rejected twice and you don’t know why. Pasadena’s plan check process is technical, and resubmittals that don’t address the reviewer’s comments get rejected again. If you’re stuck in a correction loop, you need someone who reads the comments and fixes the drawings. We’ve done it for years.
- The price changed at the door. A contractor who quotes $220,000 and then hands you a change order for $48,000 during framing is not running an honest job. The Garrison Standard is a written price before any work starts. If the number moves, it’s because you changed the scope, not because we “discovered” something we should have seen on day one.
- The work failed inspection and no one’s fixing it. A failed inspection means the work doesn’t meet code, and code compliance is not optional. If the contractor walked away, the defect is still there. Our 365-Day Done Right Promise covers workmanship defects in writing, and if something fails inside that year, we return at no charge and correct it.
Our Process, Step by Step
- 1
Site visit and feasibility assessment. Reed Calloway or a senior project lead walks your Pasadena property, reviews the lot dimensions, checks the existing utilities, and talks through what you want. We look at setbacks, access, and the condition of the garage or yard. You’ll leave that meeting knowing whether an ADU fits your lot and roughly what it will cost.
- 2
Written price proposal. Within days of the site visit, we hand you a written price. It includes design, engineering, permits, construction, and the one-year written guarantee. The scope is spelled out line by line. This is the number you approve, and it does not change unless you change the scope.
- 3
Plans, permits, and pre-construction. We produce the permit-ready plan set, submit to Pasadena’s Building & Safety Division, and track the review cycle. We handle corrections and resubmittals. Once the permit is issued, we order materials, schedule utility locates, and set the construction window.
- 4
Construction and inspections. The background-checked, uniformed crew builds the unit to the approved plans, with inspections scheduled at each required stage – foundation, framing, rough mechanical, insulation, and final. You’re kept informed at every step, and the site stays clean at the end of each workday, per The Garrison Code.
- 5
Final walkthrough and guarantee activation. We walk the finished ADU with you, demonstrate the systems, and hand you the written guarantee. It covers workmanship defects for 365 days from completion. If something fails inside that year, we return at no charge and make it right.
How Much Does ADU Builders Cost in Pasadena?
A JADU conversion in Pasadena typically runs $90,000 to $150,000 before permit fees. A garage conversion runs $180,000 to $260,000. A detached backyard ADU runs $280,000 to $380,000, depending on square footage and finish level. These are real numbers from real Pasadena projects, not national averages pulled from a website. Your price depends on the foundation type, the utility distances, the finish level you choose, and whether the city requires design review for your neighborhood. Prefab units from Abodu or Cover can land on the lower end for detached construction, while fully custom conventional builds with James Hardie siding and premium finishes land higher.
What affects the price: site access (can a concrete truck reach the backyard or do we pump), soil conditions (expansive clay costs more to engineer), existing utility capacity (an older home may need a panel upgrade), and the Pasadena design review process in certain districts. How to avoid overpaying: get a written line-item price, not a verbal estimate; ask whether the permit fees are included; ask who handles the plan check corrections. What’s included in our free estimate: a site visit, a feasibility assessment, and a written price proposal with the full scope spelled out. Call (626) 657-5541 to schedule yours.
Our Service Area Near Pasadena
Fielding ADU Pasadena serves Pasadena and the surrounding San Gabriel Valley communities, including ADU Builders in Burbank, ADU Builders in Arcadia, La Cañada Flintridge, Temple City, Highland Park, Montebello, South El Monte, Pico Rivera, East San Gabriel, South San Gabriel, and Mayflower Village. We’re a local crew, not a franchise flying in from elsewhere, and we know the permit offices and the inspectors in each of these cities. Visit our home page to see the full range of services, or stay here to learn more about ADU Builders in Pasadena specifically.
Serving Pasadena, CA - Our Local Coverage Area
We’re based in the Pasadena area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
Frequently Asked Questions About ADU Builders in Pasadena
An ADU builder is a licensed general contractor who specializes in accessory dwelling units – designing, permitting, and constructing them from start to finish. Unlike a general remodeler who occasionally takes an ADU job, a specialist handles the Pasadena-specific zoning rules, the state ADU mandates, and the permit process as routine work. Reed Calloway and the Fielding ADU Pasadena team have done this exclusively since 2006.
A typical Pasadena ADU takes 8 to 14 months from first plan to final inspection, depending on unit type and city review cycles. Prefab units can cut on-site construction time, but the permit process still runs on the city’s clock, not ours. Your written proposal includes a construction schedule, and we hold to it. Call (626) 657-5541 for a timeline specific to your project.
A JADU runs $90,000 to $150,000, a garage conversion runs $180,000 to $260,000, and a detached backyard ADU runs $280,000 to $380,000 before permit fees. The exact number depends on your lot, your finish choices, and the build method. We give you a written price before any work starts, so the number you approve is the number you pay. Call (626) 657-5541 for an exact quote – estimates are free.
Yes. We work directly with Abodu, Cover, and Dvele, and we know their standard models, site-prep requirements, and permit packages. We handle the foundation, utilities, and city paperwork, then coordinate the installation. The prefab price goes in writing just like a conventional build, and the one-year guarantee covers the complete project.
ADU construction is planned work, not emergency work – no one builds a legal dwelling same-day, and any contractor who says otherwise is not being straight with you. What we do offer is a live person on the phone 24 hours a day, 7 days a week. If you have a question at midnight about your project or you need to schedule a site visit, call (626) 657-5541 and a person answers.
Yes, in writing. The 365-Day Done Right Promise covers workmanship defects for one full year from project completion. If something fails inside that year, we return at no charge and correct it. The guarantee is spelled out on paper – what it covers, how long it runs, and exactly how we make it right. No verbal promises, no fine print games.
Start by gathering your property’s parcel number, any existing survey documents, and your budget range. Then call us at (626) 657-5541 to schedule a free site visit. Reed Calloway or a senior project lead will walk the lot, answer your questions, and hand you a written price proposal. You’ll know whether the project is feasible and what it costs before you spend a dollar.
Schedule Your ADU Builders Service in Pasadena Today
You’ve already dealt with a contractor who missed the schedule or moved the price. You don’t need that again. Call Fielding ADU Pasadena at (626) 657-5541 and talk to a live person – 24 hours a day, 7 days a week. We’ll schedule a free site visit, walk your property with you, and hand you a written price before any work starts. The number you approve is the number you pay, and the one-year written guarantee backs every nail. Call now for your free, no-obligation estimate.
Written by Reed Calloway, Owner at Fielding ADU Pasadena, serving Pasadena since 2006.
