ADU Before & After in Pasadena, CA
Talk is cheap. We could tell you we build clean ADUs, hit permit deadlines, and leave the site better than we found it. But you’d be right to want proof. This page shows what actually happens when a Pasadena lot goes from unused space to a finished, permitted dwelling. We’re not showing renderings. These are the transitions our crews execute week in and week out under The Garrison Code: show up in the window, price in writing, by the book, leave it clean, stand behind it for a year.
Recent Transformations
Detached Garage to One-Bedroom Backyard ADU
The problem: a 1930s detached garage off a rear alley in the Bungalow Heaven area. Original slab was cracked, the roof framing had sagged, and the structure sat six inches from the side property line. We lifted the roof, retained the original roofline at the street-facing side to keep the neighborhood character, and rebuilt the interior as a 480-square-foot one-bedroom with a full bath and kitchenette. The side setback stayed as-is because we filed a setback variance (the city’s written permission to build closer to the property line than the standard rule allows) and got it approved before framing started. Result: the owner now rents it for long-term income and the exterior still looks like the garage their neighbors remember.
Backyard Slope to Two-Bedroom Prefab ADU
The lot sat in the San Rafael Hills with a 14% grade and drainage that ran toward the house. Every conventional builder the owner talked to wanted to cut and fill the whole yard, which would have meant retaining walls pushing $60,000 before any living space got built. We brought in a soils engineer, pinned the pad to bedrock, and specified a Dvele modular unit that arrives panelized and goes up in days rather than months. The foundation work took three weeks. The module set took four days. The owner avoided a winter of open excavation, and the Grade 4 concrete stem wall we poured handles the hillside pressure without a single crack line showing through the drywall.
Covered Patio to Attached Junior ADU
Pasadena allows junior ADUs to attach directly to the main house with separate entrances, and this 220-square-foot covered patio in the Madison Heights neighborhood was already under the main roof. That saved the owner roughly $120 per square foot compared to a ground-up detached build because the roof, one wall, and the foundation were already there. We enclosed the open sides with James Hardie siding and a new insulated wall assembly, ran a 40-amp subpanel from the main service, and plumbed an efficiency kitchen and full bath along the existing wet wall. The JADU was permitted as a separate dwelling unit, which means it rents independently and adds to the property’s assessed income potential.
Oversized Two-Car Garage to Three-Bedroom Rental House
This one was a 700-square-foot garage in the Historic Highlands, and the owner’s first instinct was a straight conversion. But the slab had no rebar and the roof framing was attic trusses never designed for ceiling insulation. We pulled the structure down to the slab edge, poured a new monolithic foundation with proper footings, and framed a 1,050-square-foot three-bedroom under a pre-engineered roof. The owner chose conventional framing over a prefab platform because they wanted 9-foot ceilings and space for a stacked laundry. Total build time: 14 weeks from demolition to final inspection. The garage conversion cost more than a simple remodel would have, but the finished building rents at full market rate instead of a discounted converted-garage rate.
Awkward Side Yard to Studio ADU Above Storage
The owner had a 120-foot side yard in Lower Arroyo that did nothing but collect leaves. We designed a 400-square-foot studio ADU stacked above a single garage bay, which kept the project inside the city’s height limit for a two-story detached structure while adding covered parking the lot never had. The foundation is a stem wall over a crawlspace, because building over a garage requires fire separation at the floor assembly, and we used a cementitious floor underlayment to deaden sound between the two levels. The ADU’s entry faces the main house across a small landscaped court, so it feels like a second home rather than a backyard afterthought.
What These Projects Share
Every job above started with a written price before a single nail was driven. That’s not a pitch, it’s how Garrison Partners has operated since 2006, and Fielding ADU Pasadena runs the same way. The number you approve on day one is the number on the final invoice. If a change comes up mid-project, you get a written change order before work continues, with the new line-item price in front of you.
Each project is also covered by The Garrison Standard: a written one-year guarantee on workmanship. It spells out what’s covered, how long it runs, and exactly how we make it right if something fails. If a door binds, a seam opens, or a fixture leaks inside that year, we come back and correct it at no charge. Reed Calloway signs that guarantee on every Fielding ADU project in Pasadena, and he’s the person you’ll see on site checking the work against the plan.
We also don’t send strangers to your property. Every crew member is background-checked before they set foot on a job, and they arrive in uniform. You know who’s on your site, and you can reach a live person at (626) 657-5541 anytime, day or night. Not a voicemail tree, not a callback queue. Someone picks up.
How Long Do These ADU Projects Take in Pasadena?
Pasadena’s planning and building departments move at a pace you can plan around if you file correctly the first time. A straightforward garage conversion to an ADU, where the structure is already permitted and the foundation passes inspection, runs 10 to 14 weeks from permit approval to final. A ground-up detached ADU, especially one requiring a setback variance or hillside soils work, runs 16 to 24 weeks. Prefab and modular platforms like Abodu, Cover, Mighty Buildings, Boxabl, and Plant Prefab compress site time significantly: once the foundation is in, a panelized module set often goes up in under two weeks. But the foundation, utility trenching, and city inspections still need the time they need. Concrete cures on the city’s clock, not ours.
What Do ADU Projects Cost in Pasadena?
Here are real ranges from Pasadena projects we’ve priced in the last two years, before permit fees:
- Garage conversion to ADU (400-550 sq ft): $150,000 to $220,000
- Junior ADU attached to the main house (220-350 sq ft): $90,000 to $140,000
- Detached studio ADU, ground-up (400-500 sq ft): $180,000 to $260,000
- Detached two-bedroom ADU, ground-up (700-900 sq ft): $260,000 to $380,000
- Prefab or modular ADU, installed on your foundation: $200,000 to $350,000 depending on platform and site prep
Permit fees in Pasadena add roughly $8,000 to $18,000 depending on project valuation and school impact fees. Any builder who quotes you a Pasadena ADU “all-in” and doesn’t break out the fee schedule is guessing. We don’t guess. The written price includes line items, and you’ll see exactly what goes to the city and what goes to the build.
Want Results Like These?
If your garage, side yard, or backyard looks like the “before” photos on this page, the next step is a conversation. We’ll walk your property, talk through what’s buildable under Pasadena’s current ADU rules, and hand you a written price before you commit to anything. Call (626) 657-5541 to schedule a free estimate. Reed Calloway or a member of the Fielding ADU team will answer the phone.
Written by Reed Calloway, Owner at Fielding ADU Pasadena, building additions and ADUs in Pasadena under The Garrison Standard since 2006.
