







A free site visit, a check of what your lot allows and a written, line-item price.
Get your free estimateADU Company in Lennox, CA
An ADU in Lennox runs between $180,000 and $320,000 for a detached one-bedroom unit with a kitchen and bath, before site preparation. Most Lennox jobs land in the $210,000 to $260,000 range, depending on lot access, existing concrete, and utility distances. What makes Lennox work different is the lot geometry: many homes here sit on compact 4,000 to 5,500-square-foot parcels, which means setback compliance and foundation placement require careful measurement long before a permit application goes in. Call (472) 248-8213 when you want a written price for your specific property.
Why Lennox Homes Are Different

Lennox is an unincorporated Los Angeles County pocket bordered by Inglewood to the north, Hawthorne to the south, and the 405 to the east. Homes here are predominantly stucco bungalows and post-war single-story structures built between the late 1940s and early 1960s, with flat or low-pitched roofing and slab foundations. That age matters when you add square footage: original electrical panels are often 100 amps, which an ADU with a mini-split, electric range, and laundry will exceed, meaning a panel upgrade commonly rides along with the build. The county’s unincorporated status also means ADU permits go through LA County Planning rather than a city planning desk, and that process has its own review timelines and inspector routing. Lennox sits on mostly flat land with no meaningful grade changes, so foundation costs stay predictable. The bigger variable on Lennox lots is how much of the rear yard the existing house and driveway have already consumed.
Our crews confirm lot lines and setback distances, also known as the required gap between a new structure and the property line, before drawings are finalized. That single step prevents the most common Lennox surprise: a design that fits on paper but not on the parcel once the survey is staked.
Our Main Lennox Services
Most Lennox homeowners reach out for one of two reasons: a detached ADU in the rear yard, or an attached addition that expands the original footprint. Each service has its own Lennox page with full pricing and process detail.
Home Addition Contractor in Lennox
A home addition in Lennox typically extends a single-story home at the rear or side property line, adding a bedroom, a family room, or a primary suite with its own bath. The original framing, stucco exterior, and flat roof profile have to be matched closely enough that the addition doesn’t read as an afterthought, and that’s a detail we plan from the first framing walk. Because Lennox lots are compact, we spend real time on where the addition meets the existing rear yard, and whether the remaining outdoor space still works for the homeowner. The written price includes that planning time, not just nails and lumber. Home Addition Contractor in Lennox

ADU Builders in Lennox
Detached ADUs are the fastest-growing request in Lennox, driven mostly by extended-family living and rental use. A rear-yard unit in the 400 to 700-square-foot range is the typical build here, with one or two bedrooms, a full bath, and a compact kitchen. Lennox lots often have older concrete slabs in the rear that can be removed and reused as a foundation pad location, which trims excavation expense when conditions allow. Utility runs from the main house to the ADU are shorter on these small parcels, which keeps trenching and electrical distances more predictable. ADU Builders in Lennox

Room Addition Contractor in Lennox
A room addition in Lennox is the smaller-scope path: one room, one purpose, one permit. Homeowners ask for home offices, ground-floor bedroom additions for aging family members, and expanded kitchens that open onto the rear yard. The work involves tying rooflines into the existing structure, which on Lennox’s mostly flat-roof and low-slope homes means more flashing and membrane detail than on a pitched suburban roof. The county permit process for a single room is lighter than a full addition, and the occupied home has to stay livable during the build, so we sequence work to keep the house sealed at the end of every day. Room Addition Contractor in Lennox

What happens when you call
- 1
A real person answersNo phone trees - you reach a local pro.
- 2
You get an upfront price rangeHonest numbers before anyone is dispatched.
- 3
A background-checked tech heads outLicensed & insured, dispatched right away.
- 4
You approve before work beginsNothing starts until you say go.
Brands We Service in Lennox
We work with prefab and modular ADU systems from Dvele, Mighty Buildings, and Boxabl, plus James Hardie exterior cladding for site-built additions. Prefab panels and modules are delivered to Lennox lots on scheduled truck deliveries, and we coordinate crane or forklift placement with the county’s right-of-way rules before arrival. See our brands for full product detail and which system fits a compact Lennox lot.
Pricing for ADU Company in Lennox, CA
| Service | Typical range in Lennox |
|---|---|
| Detached ADU, 400 – 700 sq ft | $180,000 – $320,000 |
| Garage conversion to ADU | $120,000 – $180,000 |
| Attached home addition, 300 – 500 sq ft | $150,000 – $250,000 |
| Room addition, single bedroom | $60,000 – $110,000 |
| Room addition, kitchen expansion | $80,000 – $150,000 |
| Primary suite addition | $110,000 – $190,000 |
| Site preparation and grading | $8,000 – $22,000 |
| Utility trenching and connection | $5,000 – $14,000 |
| Electrical panel upgrade, 100A to 200A | $3,500 – $6,500 |
| Foundation work for detached unit | $18,000 – $40,000 |
Two things push Lennox prices higher than the countywide average: older electrical panels that need a service upgrade before inspection, and rear yards where the existing slab has to be removed before new foundation work starts. Every written price from us includes the full build scope, so neither of those becomes a surprise line item after work begins.
Neighborhoods We Serve in Lennox
We serve every part of Lennox, from the blocks along Lennox Boulevard to the residential streets east of Inglewood Avenue and the quiet pockets north of Imperial Highway. Response and scheduling are coordinated from our Los Angeles office, with crews dispatched locally to Lennox each day.
- Lennox Town Center area
- East Lennox, near the 405
- North Lennox, bordering Inglewood
- South Lennox, near Hawthorne
- West Lennox, along Inglewood Avenue
Service Area – Cities Near Lennox
We also run ADU and addition projects in the surrounding metro area, including Los Angeles, CA, Long Beach, CA, Anaheim, CA, and Riverside, CA. Lennox remains the central service area for this team, but if your property sits within a mile of the city boundary, give us a call and we’ll confirm coverage.
Serving Lennox, CA - Our Local Coverage Area
We’re based in the Lennox area and know this community well. Use the map below to see our service coverage - if you’re nearby, we can almost certainly help.
FAQs About ADU Company in Lennox

LA County Planning typically reviews an ADU application within 60 days from submittal, assuming the plans are complete and no corrections are requested. A site survey and ready-to-issue drawings shorten that timeline, and that’s why we handle both before submitting.
Yes. State law requires accessory dwelling units of at least 800 square feet to be allowed on any residentially zoned lot regardless of size, and Lennox parcels under 5,000 square feet can usually support a compact rear-yard unit. The actual buildable envelope depends on your specific setback distances, which we verify before pricing.
We prepare the plans, submit the application to LA County Planning, and pull the permit once approved. Inspections are scheduled by our team and walked with the county inspector on site. Call (472) 248-8213 for a free written estimate on your Lennox property.
What happens when you call
- 1A real person answersNo phone trees - talk to a local adu pro.
- 2You get an upfront price rangeHonest numbers before anyone is dispatched. No surprises.
- 3We come out and measureLicensed & insured, at a time that suits you - the visit and the quote are both free.
- 4You get the price in writingLine-itemed, yours to keep, and nothing starts until you say go.
What Lennox Customers Say
"Itemized estimate with allowances laid out. Final cost was within a hair of the quote."
- Naomi R."Backyard ADU for my mother. The project manager showed ID and walked me through the permit steps, the foundation plan, and the schedule. Moved her in on time."
- Margaret C."Insulated the walls and ceiling properly. It stays comfortable even in July."
- Tamika W.



