ADU Builder in Pasadena, CA

Dn Builders Group Inc Services designs and builds accessory dwelling units in Pasadena — garage conversions, detached backyard units, attached units and JADUs — from drawings and permits through final inspection. Pasadena writes its own ADU rules, limits units on narrow hillside streets and protects trees on private lots, so we check all three before anyone draws a floor plan.

What we build

For permits, landmark districts and the presale certificate, see our Pasadena contractor page and remodeling in Pasadena.

Pasadena's ADU ordinance and the state's review of it

Pasadena adopted its current ADU rules as Ordinance No. 7420 on April 15, 2024, in Zoning Code Section 17.50.275. On February 26, 2025 the California Department of Housing and Community Development sent the city a findings letter listing where that ordinance did not match state law. The ordinance allowed only one “exemption ADU” on a single-family lot, while the state lets a homeowner combine a converted ADU, a new detached ADU and a JADU; it required a front setback that could block an 800-square-foot unit the state guarantees; and it applied parking to units the state exempts. It also had not picked up the January 1, 2025 rules allowing up to eight detached ADUs on a lot with existing apartments.

The city brought ADU amendments back to Council in early 2026. An older handout may simply be out of date, so we design to the state minimum, then check the current text of 17.50.275 at submittal. For the statewide count, see how many ADUs you can build on one lot in 2026.

Hillside Overlay lots on narrow streets

This is the rule most specific to Pasadena. In the Hillside Overlay Districts, lots served by a public or private street 26 feet wide or narrower are limited to the statewide exemption ADUs only — essentially a conversion of existing space, a JADU, or a new detached unit of up to 800 square feet with four-foot side and rear setbacks. The city's staff report counted about 1,600 properties, roughly 5.3 percent of single-family-zoned lots, and tied the limit to evacuation: those streets sit in Very High Fire Hazard Severity Zones, and the Pasadena Fire Code wants fire roads 20 feet clear.

On those lots the question becomes how to get the most out of 800 square feet, and the unit also falls under wildfire construction rules, priced in what Chapter 7A fire hardening costs, and the site work behaves like any steep lot, covered in hillside lots, the hidden costs.

Pasadena's trees decide where a backyard unit goes

Pasadena's City Trees and Tree Protection Ordinance, Municipal Code Chapter 8.52, reaches onto private property. It protects native trees — the code lists thirteen native species, coast live oak and California sycamore among them — above about 8 inches in trunk diameter measured 4½ feet above grade, along with designated landmark trees, and, outside the RS and RM-12 zones, mature trees of 19 inches or more. Removal needs a permit and findings, replacement can be charged at appraised value, and protected trees on a job site are monitored for three years.

An old oak in the back third of the lot can decide the footprint, the foundation and the utility trench, so we locate protected trees before the site plan is drawn and design around them.

PWP and the utility run

Electrical service in Pasadena comes from Pasadena Water and Power, not Southern California Edison or LADWP, so any service upgrade or separate meter for the ADU is coordinated with PWP. An older 60- or 100-amp panel rarely carries a second kitchen and heat pump, so the upgrade becomes the critical path — see how panel upgrades differ by utility.

What an ADU costs

Typical Los Angeles market ranges, not a quote: a garage conversion $100,000–$200,000, a JADU $40,000–$100,000, a detached 600–800 sq ft unit $150,000–$350,000. Units of 750 sq ft or less are exempt from impact fees under state law. Details in what an ADU costs in 2026, garage conversion costs and ADU vs JADU.

Licensed and bonded

Dn Builders Group Inc Services holds an active California General Building license (#1139710), carries a $25,000 surety bond, and is fully insured. In California any project over $500 in labor and materials legally requires a licensed contractor. Verify the license with the California Contractors State License Board before you sign anything — with us or with anyone else. Here is how to check a contractor's license.

How we work

We walk the lot, check the zoning, the street width and the trees, and give you a fixed, itemized scope before anything is demolished. Permits are pulled by us. Change orders are approved in writing, never sprung at the end. You get a weekly update, every week, and a detailed walkthrough when we finish. You can see finished work on our portfolio page.

Questions

Are you a licensed contractor for ADUs in Pasadena?

Yes. Dn Builders Group Inc Services holds an active California General Building contractor license (#1139710), carries a $25,000 surety bond, and is fully insured. We handle ADU drawings, permits through the Pasadena Permit Center, PWP coordination and inspections.

How many ADUs can I build on a single-family lot in Pasadena?

State law allows a converted ADU, a new detached ADU and a JADU on the same single-family lot. In February 2025 the state housing department told Pasadena its ordinance, which allowed only one exemption ADU, did not match that rule, and the city has since taken amendments back to Council. We confirm the current text at submittal.

Can I build an ADU on a Pasadena hillside lot?

Usually yes, but on a narrow street the options shrink. In the Hillside Overlay Districts, lots on streets 26 feet wide or narrower are limited to the statewide exemption ADUs, such as a conversion, a JADU or a detached unit of up to 800 square feet. The city counted about 1,600 properties in that category.

What does an ADU cost in Pasadena?

A garage conversion typically runs $100,000 to $200,000, a JADU $40,000 to $100,000, and a detached 600 to 800 square foot unit $150,000 to $350,000. These are typical Los Angeles market ranges, not a quote. Trees, the street and the electrical panel move the number most.

Where else we work

Altadena, La Cañada Flintridge, Glendale, and Greater Los Angeles.