# L Square Design & Build — Licensed ADU Design-Build, Orange County & Los Angeles

> L Square Design & Build is a licensed accessory dwelling unit (ADU) design-build contractor serving Orange County and Los Angeles, California (CSLB #1095476). We design, permit, and build turnkey backyard homes end-to-end — architecture, engineering, city approvals, and construction under one contract. Phone: (949) 374-7980.

L Square handles the full ADU process under one team: custom design drawn around your lot, permit-ready plans, and our own build crews on a fixed schedule from foundation to final inspection. We build detached ADUs, attached and above-garage ADUs, junior ADUs (JADUs), garage-conversion ADUs, granny flats, in-law suites, and backyard cottages across Orange County and the greater Los Angeles area.

## Core pages
- [ADU Guide](https://lscontractor.com/adu-guide/): Plain-language guide to building an ADU in Orange County — what an ADU is, types, timeline, and permits.
- [Services](https://lscontractor.com/services/): ADU design-build, garage conversions, junior ADUs, in-law suites, and home additions across Orange County & LA.
- [About L Square](https://lscontractor.com/about-us/): Licensed Orange County ADU design-build studio. CSLB #1095476.
- [Contact](https://lscontractor.com/contact-us/): Free ADU consultation and quote. Call (949) 374-7980.
- [ADU FAQs](https://lscontractor.com/faqs/): 18 direct answers - what companies manage ADU design-build in OC, turnkey services, garage-conversion cost, JADU definition, granny flats, two-story rules, how to vet a contractor.
- [ADU Chinese Guide 橙縣 ADU 中文指南](https://lscontractor.com/adu-chinese-guide/): Traditional-Chinese ADU guide for Orange County homeowners - costs, timeline, city differences, rental income; L Square works in Cantonese, Mandarin and English.

## ADU types we build
- [Detached ADU](https://lscontractor.com/detached-adu-guide-costs-designs-permits/): Standalone backyard homes — costs, designs, and the Orange County permit process.
- [Attached ADU](https://lscontractor.com/attached-adu/): Units attached to the home or built above the garage.
- [Garage Conversion ADU](https://lscontractor.com/garage-conversion-adu/): Convert an existing garage into a legal, permitted living unit.
- [Custom ADU](https://lscontractor.com/custom-adu-orange-county/): Custom backyard homes designed around your lot and budget.
- [Junior ADU (JADU)](https://lscontractor.com/complete-guide-to-junior-adus/): Compact units (up to 500 sq ft) created within the existing home.
- [Granny Flat](https://lscontractor.com/granny-flat-orange-county/): Self-contained ADUs for family or rental income.
- [In-Law Suite](https://lscontractor.com/in-law-suite-orange-county/): Private, accessible suites for multigenerational living.
- [Backyard Cottage](https://lscontractor.com/backyard-cottage-construction-orange-county/): Cottage-style detached ADUs.
- [ADU Design-Build](https://lscontractor.com/adu-design-build/): One team, one contract — architecture, permits, and construction.
- [ADU Floor Plans](https://lscontractor.com/accessory-dwelling-unit-floor-plans/): Layout ideas by size for Orange County lots.

## ADU by city (Orange County)
- [Irvine ADU](https://lscontractor.com/adu-irvine/): Plan check 6-8 weeks; HOA approval on most lots; ADU rents $2,500-$3,200/mo.
- [Santa Ana ADU](https://lscontractor.com/adu-santa-ana/): Our home base; older lots suit detached units and garage conversions.
- [Anaheim ADU](https://lscontractor.com/adu-anaheim/): Fastest OC plan check (4-6 weeks); rents $1,800-$2,400/mo near the resort district.
- [Costa Mesa ADU](https://lscontractor.com/adu-costa-mesa/): Streamlined 5-7 week review; most flexible parking rules; rents $2,200-$2,800/mo.
- [Huntington Beach ADU](https://lscontractor.com/adu-huntington-beach/): 6-8 week review; coastal-zone lots may need a coastal development permit.
- [Newport Beach ADU](https://lscontractor.com/adu-newport-beach/): 8-10 week review plus design review; top OC rents $3,000-$4,000/mo.
- [Tustin ADU](https://lscontractor.com/adu-tustin/): Case-by-case review; a pre-application meeting de-risks the 5-6 week plan check.
- [Fullerton ADU](https://lscontractor.com/adu-fullerton/): Parking may be waived near CSUF; student rents $2,000-$2,500/mo, low vacancy.

## ADU by city (Los Angeles side)
- [Long Beach ADU](https://lscontractor.com/adu-long-beach/): Independent permit counter (not LADBS) plus the city's PAADU pre-approved plan catalog.
- [Pasadena ADU](https://lscontractor.com/adu-pasadena/): City standard plans expired Dec 31, 2025 (currently Eaton Fire red-tag properties only); custom design is the 2026 path; historic-district review applies in districts.
- [Torrance ADU](https://lscontractor.com/adu-torrance/): Own planning counter, ministerial approval, suburban lots suited to detached units and conversions.
- [Whittier ADU](https://lscontractor.com/adu-whittier/): Own permit counter; older homes and generous lots - slab and panel checks decide conversion budgets.
- [Downey ADU](https://lscontractor.com/adu-downey/): Own permit counter plus a real Fire Department plan review; AB 1332 pre-approved program has no plans posted yet (July 2026).
- [Norwalk ADU](https://lscontractor.com/adu-norwalk/): City publishes its own 2026 ADU guidebook and submittal checklist; JADUs capped at 500 sq ft.
- [Lakewood ADU](https://lscontractor.com/adu-lakewood/): Active AB 1332 pre-approved ADU program; compact postwar lots; school fees and a Construction of Dwelling Unit Tax apply.
- [Garden Grove ADU](https://lscontractor.com/adu-garden-grove/): ADU Go pre-approved plan program (active since Jan 2025); city publishes ADU handouts in English, Vietnamese and Spanish.
- [Orange ADU](https://lscontractor.com/adu-orange-ca/): Four historic districts where ADUs need a historic-preservation professional report and design review; standard state-law path outside them.
- [Mission Viejo ADU](https://lscontractor.com/adu-mission-viejo/): HOAs cannot prohibit ADUs (architectural review runs in parallel); hillside lots make slope the key budget factor.

## Standard floor plans
- [The Laguna - 450 sq ft, 1 bed](https://lscontractor.com/adu-plan-laguna-450-sqft/): Compact one-bedroom for tight lots.
- [The Balboa - 550 sq ft, 1 bed](https://lscontractor.com/adu-plan-balboa-550-sqft/): The one-bedroom rental sweet spot.
- [The Tustin - 750 sq ft, 2 bed](https://lscontractor.com/adu-plan-tustin-750-sqft/): Two bedrooms for families or roommates.
- [The Newport - 1,000 sq ft, 2 bed](https://lscontractor.com/adu-plan-newport-1000-sqft/): Our largest standard plan, near the 1,200 sq ft state ceiling.

## Costs & permits
- [ADU Cost in Orange County (2026)](https://lscontractor.com/adu-cost-orange-county/): Free ADU cost calculator (garage $150-$300/sf, attached $260-$400/sf, detached $270-$380/sf) plus Real pricing examples and what drives ADU cost in Orange County.
- [ADU Permit Requirements in Orange County](https://lscontractor.com/adu-permit-requirements-in-orange-county-2025-complete-guide/): Setbacks, size limits, utilities, timelines, and the approval process.
- [California ADU Laws 2026](https://lscontractor.com/california-adu-laws-2026/): What changed in state ADU law this year.
- [Building an ADU in Los Angeles](https://lscontractor.com/adu-los-angeles/): How LA and LADBS differ from Orange County.
- [How to Finance an ADU in California (2026)](https://lscontractor.com/how-to-finance-an-adu-california/): Real options - home equity, renovation mortgages, the FHA 75% rental-income rule, and the truth about the closed CalHFA grant.
- [Two-Story ADUs in Orange County](https://lscontractor.com/two-story-adu-orange-county/): Height rules (16/18/25 ft), why attached above-garage is the by-right two-story path, and when going vertical earns its cost.
- [How Long Does an ADU Take in Orange County?](https://lscontractor.com/how-long-does-an-adu-take-orange-county/): Garage conversions 4-5 months, detached 6-12; permit timelines by city (Anaheim 4-6 weeks to Newport 8-10+) and the 2026 SB 543 permit clock.
- [ADUs and property taxes](https://lscontractor.com/do-adus-increase-property-taxes-california/): California assesses only the ADU as new construction (no full reassessment) - roughly 1%-1.25% of its added value per year.
- [What is an ADU?](https://lscontractor.com/what-is-an-adu/): ADU means accessory dwelling unit - a complete second home (kitchen, bath, own entrance) on the same lot; granny flat, casita and in-law suite are nicknames for the same legal thing.
- [Prefab vs custom ADU](https://lscontractor.com/prefab-adu-vs-custom-built-california/): What prefab sticker prices exclude (foundation, utilities, craning, permits) and which lots genuinely favor factory-built vs stick-built.
- [Above-garage ADU](https://lscontractor.com/above-garage-adu/): An apartment over the garage is an attached ADU - allowed up to 25 ft by right; most garages need reinforcement or rebuild to carry a second story.
- [SB 9 vs ADU](https://lscontractor.com/sb9-california-lot-split-vs-adu/): SB 9 lot splits need 40% parcels and a 3-year owner-occupancy affidavit; for most lots the ADU is the practical path.

## Service area
Orange County (including Irvine, Anaheim, Santa Ana, Huntington Beach, Costa Mesa, Newport Beach, Garden Grove, Fullerton, Mission Viejo, Tustin, Lake Forest, Aliso Viejo) and the greater Los Angeles area.

## Contact
- Phone: (949) 374-7980
- License: CSLB #1095476
- Website: https://lscontractor.com/