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
Adding an accessory dwelling unit in Pasadena typically costs between $220,000 and $480,000 for a turnkey build, and most homeowners get a written price before any work begins when they call (626) 658-3527. That’s the standard we’ve held since our parent company started in 2006, and it’s why Troy Eastman leads every Benson ADU Pasadena project with a written guarantee, not a handshake. We’re part of the Relay Home Co. family, which means our clients get the same transparency from a contractor that they expect from a rideshare app: a confirmed price, a real arrival time, and photo proof of progress. If you’ve been sitting on ADU plans because every contractor you called gave you verbal ballparks and vague timelines, you’re in the right place. We build with Abodu, Cover, Dvele, Mighty Buildings, Boxabl, Plant Prefab, and Tuff Shed, plus James Hardie cladding, so you can research every product we recommend before you sign anything. Same-week site visits are available across Pasadena, and a live person answers our phone around the clock.
ADU Construction
ADU Construction is the full-scope build of an accessory dwelling unit on your Pasadena property, from foundation to final inspection, and it’s the service most homeowners need when they want a turnkey rental, in-law suite, or home office without moving. Benson ADU Pasadena handles every phase, including permitting, site prep, utility connections, framing, finishes, and the final walkthrough with the city. A site-built ADU in the Pasadena area generally runs $300,000 to $480,000, while a prefab ADU from Abodu, Cover, or Dvele typically lands between $220,000 and $350,000 installed.
Permit-Ready Builds
We file the plans, pull the permits, and manage every inspection. That means you won’t be making trips to the planning counter or chasing a plan checker. We treat the permit process as part of the build, not a separate headache.
Fixed-Price Framing
The written price we give you before work starts includes framing, roofing, drywall, electrical, plumbing, and finishes. If a change order comes up, it’s in writing before it’s approved. No scope creep billed after the fact, ever.
Detached ADU
A Detached ADU is a standalone unit built separately from your main house, usually in the rear yard, and it’s the right choice when you want a completely private rental or the largest possible floor plan. Benson ADU Pasadena builds detached units from both site-built framing and prefab panel systems, including Abodu, Cover, and Dvele models, which arrive as factory-built modules and are assembled on your foundation. Detached ADUs in Pasadena tend to run $280,000 to $480,000 depending on size, site conditions, and finishes, with prefab options often coming in on the lower end.
Setback Solutions
A setback is the required distance between a structure and your property line, and detached ADUs have to respect them on all sides. We survey your lot before design begins so the unit fits where it’s legal, not where it looks nice in a rendering.
Foundation Options
Your soil and slope determine whether you need a slab, a raised foundation, or piers, and that affects your total cost. We test and report on site conditions before we quote, so the price reflects what we’ll actually build on.
JADU
A JADU, or junior accessory dwelling unit, is a small unit up to 500 square feet created within the existing walls of your primary home, typically by converting a garage, a finished basement, or an attached wing, and it’s the most affordable way to add rental income in Pasadena. Benson ADU Pasadena plans and builds JADUs that meet California’s relaxed requirements for this unit type, often with a shared bathroom and a small kitchenette instead of a full kitchen. JADU projects in Pasadena usually run $80,000 to $150,000, making them the lowest-cost ADU option on the table.
Garage Conversions
Attached garages are the most common JADU starting point because the framing, roof, and foundation already exist. We convert the space, insulate it, add plumbing and electrical lines, and finish it to code. You keep the footprint and gain a rentable unit.
Owner-Occupancy Rules
JADUs have a different set of occupancy requirements than detached ADUs in California, and we’ll walk you through exactly what applies to your property. The rules affect rental strategy, so we cover them before design begins, not after the plans are filed.
ADU Plans
ADU Plans are the architectural and engineering drawings required before any construction can start, and they’re the first deliverable you’ll receive when you work with Benson ADU Pasadena. Our design team drafts plans specific to your lot, your setbacks, and your city’s ADU ordinance, then submits them for plan check. ADU plan sets in Pasadena typically cost $6,000 to $18,000 depending on whether you choose a prefab brand plan, a site-built custom design, or something in between.
Prefab Plan Sets
When you build with Abodu, Cover, or Dvele, the manufacturer supplies engineered plans that are already approved for use in many California jurisdictions. We adapt them to your specific lot and handle the submittal. This cuts design time and often trims thousands off your plan cost.
Custom Drafting
If you want a site-built ADU with a layout no prefab company offers, our drafters produce a full set of architectural, structural, and energy compliance drawings. You’ll review every page before it goes to the city, and revisions are included until the plans pass.
ADU Contractor
An ADU Contractor is the licensed general contractor who pulls the permits, coordinates the trades, and is legally responsible for bringing your ADU to code, and that’s the role Benson ADU Pasadena plays on every project we take on. We employ background-checked, uniformed technicians, and we put our 365-Day Done Right Promise in writing on every single project. General contractor fees for ADU builds in Pasadena are typically built into the total project price rather than billed separately, which is why our written estimate covers the complete scope from demo to final clean.
One Point of Contact
You get one project lead who answers your calls and texts, plus a live person on our main line 24/7. No getting bounced between a salesperson, a designer, and a foreman who each have a different answer. The person who quotes your job is accountable for it.
Subcontractor Vetting
Every electrician, plumber, and roofer who steps onto your Pasadena property is background-checked and arrives in uniform. We don’t hire day laborers off the corner and call them a crew. You’ll know who’s on your property, and we’ll have a record of their work.
ADU Design
ADU Design is the process of matching a floor plan, exterior finish, and product lineup to your lot, your budget, and how you intend to use the unit, whether that’s housing a parent, renting it out, or working from it. Benson ADU Pasadena offers design through two paths: prefab configurations from Abodu, Cover, Dvele, and Mighty Buildings, or custom site-built layouts drafted from scratch. Design fees in Pasadena typically run $3,000 to $12,000 when billed separately, but we wrap design into the full project price so you’re not paying a separate retainer.
Prefab Configuration
Prefab design means selecting a factory-built floor plan, choosing exterior cladding like James Hardie siding, and picking fixtures from a curated menu. It’s faster and often cheaper because the structural engineering is already done. You get a fixed set of options instead of unlimited, expensive customization.
Site-Built Customization
When your lot has odd angles, steep slopes, or you simply want a layout that prefab can’t offer, we design site-built. That means full architectural freedom: rooflines, window placement, ceiling heights, and square footage are all negotiable. It costs more and takes longer, but the result is one of one.
Backyard ADU
A Backyard ADU is a detached unit built in your rear yard, often visible from the main house but fully independent, and it’s the most popular ADU type in South Pasadena because it maximizes privacy and rental appeal. Benson ADU Pasadena constructs backyard ADUs using either site-built framing or panelized prefab systems, and we handle the site work, foundation, utility trenching, and landscaping restoration that a backyard build requires. Costs in Pasadena generally span $260,000 to $460,000 for a complete backyard ADU, including permit fees and utility connections.
Trenching and Utilities
Bringing water, sewer, and electrical lines from the main house to a backyard unit means digging trenches, and that work can add $10,000 to $30,000 depending on distance and soil. We include trenching in our written estimate, so the price you see is the price you pay. Not a surprise line item at the end.
Site Access Planning
The path between the street and your backyard dictates how crews and materials move onto the site. We plan access routes before we quote, because a tight side yard can change equipment choices and influence the final number.
Brands We Service
We’re authorized to build with Abodu, a California-based prefab ADU manufacturer known for complete units that arrive on a truck and are set on your foundation in a single day. Benson ADU Pasadena handles the site work, foundation, utility hookups, and finishing touches, then manages the entire permit process around Abodu’s engineered plans.
We also work with Cover and Dvele. Cover builds custom prefab panels with integrated steel framing, and Dvele focuses on high-performance, energy-efficient ADUs with a strong emphasis on indoor air quality. When you choose a James Hardie-clad prefab or site-built unit, we handle the installation to manufacturer spec so the warranty stays intact. Whether you have Abodu, Cover, Dvele, or any other make, we can help.
Signs You Need a Pro Right Now
- You’ve received three different verbal estimates. If three contractors gave you three wildly different numbers just by looking at your yard, none of them did any real takeoff. A written, line-item price requires measurements, utility checks, and city research. We do that work before we hand you a number.
- Your city sent a correction notice or code violation. An unpermitted structure on your Pasadena property can hold up a sale or refinance. Bringing it to code is a specialty job that involves as-built drawings, inspections, and sometimes partial demolition. We handle that process from notice to sign-off.
- You need rental income by a specific date. If you’ve promised a tenant, a parent, or an adult child a move-in date, the schedule matters as much as the budget. We build schedules around deadlines and publish progress with photo updates, so you never wonder where the project stands.
- Your lot has obvious site challenges. Slopes, utility lines, old trees, and short side yards all change what’s buildable and what it costs. A contractor who quotes without walking your lot is guessing. We survey and report before we propose.
- You want to research the product, not just trust the contractor. Homeowners who research Abodu, Cover, Dvele, Mighty Buildings, Boxabl, Plant Prefab, Tuff Shed, and James Hardie want to know exactly what they’re getting. We give you brand names you can verify, not an unnamed “supplier” we won’t reveal.
Our Process, Step by Step
- 1
Discovery call and site walk. You call (626) 658-3527, we talk through your goals, and we schedule a walk of your Pasadena property. Troy Eastman or a senior project lead will be on-site, measuring, testing soil where relevant, and mapping utility locations.
- 2
Written, line-item estimate. Within days of the site walk, you receive a written estimate that includes materials, labor, permits, utility work, and design. This is the price. If something changes later, it changes in writing with your signature, not as a surprise invoice.
- 3
Plan design and permit submittal. We draft or adapt your plans, submit them to the city, and answer plan check comments until approval. You get a copy of every submittal and every response, so there’s no black box between you and the permit office.
- 4
Construction with live updates. Our crews build on the schedule we agreed to, and you receive photo updates at every major milestone: foundation, framing, rough-in, drywall, finishes. You’ll see the work as it happens, not just hear about it after the fact.
- 5
Final inspection and 365-Day Done Right handoff. We walk the finished ADU with you, complete the city’s final inspection, and hand you a written 365-Day Done Right Promise. If anything covered fails within a year, we come back and make it right, free.
How Much Does ADU Builders Cost in Pasadena?
A typical ADU build in Pasadena runs $220,000 to $480,000 depending on whether you choose a prefab unit from Abodu, Cover, or Dvele, a custom site-built design, or a compact JADU conversion. Prefab units on simple sites usually land between $220,000 and $350,000. Site-built detached ADUs run $300,000 to $480,000. JADUs inside your existing home footprint are the most affordable path at $80,000 to $150,000. What moves the number: lot slope, soil condition, distance from the main house to the utility connections, whether you need a new electrical panel, and your finish level. The way to avoid overpaying is to get a written, line-item estimate that names every product, every trade, and every permit fee before work starts. That’s what we deliver on every single project at Benson ADU Pasadena. A free estimate includes the site walk, the measurements, and the written price.
Our Service Area Near Pasadena
Benson ADU Pasadena serves homeowners across Pasadena and the surrounding San Gabriel Valley, including El Monte, East Los Angeles, Monterey Park, San Gabriel, Duarte, Altadena, Boyle Heights, La Crescenta-Montrose, San Marino, South Monrovia Island, and South Pasadena. Site visits are typically scheduled within a week of your call. For a broader look at how we work across our parent company’s network, visit our home page to see the full Relay Home Co. service map.
Serving Pasadena, CA - Our Local Coverage Area
We’re based in the Pasadena area and know this community well, including nearby San Marino. 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
ADU Builders are contractors who specialize in accessory dwelling units, the secondary housing units built on single-family lots. Benson ADU Pasadena handles design, permitting, construction, and final inspection for detached ADUs, JADUs, and backyard units across Pasadena. We build with prefab manufacturers like Abodu, Cover, and Dvele, and we also frame site-built units from scratch. Call (626) 658-3527 for a free written estimate.
A prefab ADU from Abodu, Cover, or Dvele typically completes in 4 to 8 months from permit submittal to final inspection, with site-built ADUs taking 8 to 14 months. The timeline variance comes down to plan check queues, site conditions, and finish selections. We publish a schedule before we start and update you with photo proof at every milestone so you always know where the project stands.
A JADU conversion typically runs $80,000 to $150,000, a prefab detached ADU $220,000 to $350,000, and a custom site-built ADU $300,000 to $480,000. Your specific price depends on lot conditions, utility distances, finish level, and whether you choose a prefab brand or custom design. Benson ADU Pasadena provides a written, line-item estimate before any work starts. Call (626) 658-3527 to schedule a free site walk.
Yes, we’re authorized to build with Abodu, Cover, and Dvele, which means we can assemble their prefab modules, complete the site work and utility connections, and manage the permit process around their engineered plans. We also install James Hardie cladding on both prefab and site-built ADUs. If you already own a unit from one of these brands and need finishing work, we handle that too.
We’re not an emergency contractor in the sense of storm damage or flood response, but our live support line is answered 24/7, every day of the year. If you need a question answered at 9 p.m. or want to book a site walk for the weekend, someone will pick up the phone. Call (626) 658-3527 whenever you’re ready to talk.
Our 365-Day Done Right Promise covers every part of the build for a full year after handoff. If anything we installed isn’t right, we come back and make it right at no charge. We also include a free second visit if any covered repair fails. The warranty is written into every project agreement, signed before work begins.
Gather any existing property surveys, think through how you’ll use the unit (rental income, family housing, workspace), and write down your must-haves versus nice-to-haves. Then call (626) 658-3527 and we’ll handle the rest, including the site walk, measurements, and written estimate. The more honest you are about your budget up front, the better we can tailor the design.
Schedule Your ADU Builders Service in Pasadena Today
You’ll get a written price before any work starts, not a verbal guess that shifts later. Call (626) 658-3527 to book a free site walk with Troy Eastman and the Benson ADU Pasadena team. No obligation, no pressure, just a real number on paper.
Written by Troy Eastman, Owner at Benson ADU Pasadena, serving the San Gabriel Valley since 2006.
