What LEE & LEE STRUCTURAL ENGINEERING INC does

Lee & Lee Structural Engineering Inc. is a privately held, California-based structural engineering consulting firm founded in 1989 by Sang Youck Lee in Los Angeles. The firm provides structural design, analysis, and permit-ready documentation for commercial, residential, and public projects, with material expertise spanning wood, concrete, structural steel, light-gauge framing, CMU, tilt-up, and hybrid systems. It is differentiated by specialization in seismic engineering and the restoration/retrofitting of historic and non-ductile structures, a particularly relevant competency in California's seismic regulatory environment. The firm is certified as a Minority Business Enterprise (MBE) and claims over 5,000 projects delivered since inception.

The firm's technology stack is built on industry-standard structural analysis and drafting tools — ETABS, SAFE, SAP2000, and AutoCAD — combined with ENERCALC and Excel for calculation packages. All projects receive direct oversight from a licensed structural engineer from concept through construction, with services packaged into three core offerings: Structural Engineering & Design, Remodel & Adaptive Reuse (including seismic retrofits), and Permit-Ready Documentation.

Commercially, Lee & Lee operates as a B2B professional services consultancy with project-based fee engagements negotiated per scope. Its go-to-market is enterprise field sales — direct relationships with architects, contractors, and developers, supplemented by a portfolio website that functions as a credibility and contact vehicle. The firm maintains a single headquarters at 3580 Wilshire Blvd, Suite 526, Los Angeles, and serves clients primarily across California, with no disclosed digital self-serve motion, no channel partners, and no publicly disclosed pricing. Its customer base is concentrated among a recurring set of Southern California architectural firms including PLUS Architects, Corbel Architects, Group Arch, and Birba Group.

Name

LEE & LEE STRUCTURAL ENGINEERING INC

Legal name

Lee and Lee Structural Engineering Inc.

Website

https://leenlee.net

Company type

Private

Founded year

1989

Operating status

Operating

Headcount range

1–10 employees

Short description

Lee & Lee Structural Engineering Inc. is a Los Angeles-based structural engineering consultancy founded in 1989, providing design, seismic retrofit, and permit-ready documentation for commercial, residential, and adaptive reuse projects across California, primarily serving architects, developers, and contractors.

Ownership category

akta.pro rank

Product category

Structural Engineering Services

NAICS

Architectural Services (54131)

SIC

Services-Engineering Services (8711)

akta.pro primary industry

Civil & Structural Engineering Consulting (BPAHAIAA)

akta.pro secondary industry

Architectural Reconfiguration & Structural Alterations (HSAPAEAB)

Keywords

• Structural engineering design
• Seismic retrofit services
• Building permit documentation
• Adaptive reuse engineering
• Commercial structural consulting

Headquarters

HQ city

Los Angeles

HQ country

United States

HQ region

North America

Offices1 record

Markets served

GTM type

B2B

Offering type

Services

Cost components

Personnel, Operations

Revenue model

1. Structural Engineering Consulting Services: Lee & Lee generates revenue by providing structural engineering design, analysis, and consulting services to architects, contractors, developers, and building owners across commercial, residential, and public projects. Revenue is earned through project-based professional service engagements, typically billed per project scope or milestone.

Go-to-market motion1 record

Distribution channels1 record

Marketing channels1 record

Core offering

Lee & Lee Structural Engineering Inc. provides project-based structural engineering design, analysis, remodel/adaptive reuse, and permit-ready documentation services for commercial, residential, and public building projects across California. Services span wood, steel, concrete, CMU, tilt-up, and hybrid structural systems and include specialized seismic retrofit work, delivered using ETABS, SAFE, SAP2000, and AutoCAD.

Product overview

Lee & Lee Structural Engineering Inc. is a structural engineering consulting firm offering three core service offerings: Structural Engineering & Design (covering wood, steel, concrete, CMU, and tilt-up systems), Remodel & Adaptive Reuse (including seismic retrofits and renovations), and Permit-Ready Documentation (structural calculations and construction drawings). The firm serves commercial, residential, and public projects across California and beyond, working with various building types including residential complexes, commercial buildings, hotels, factories, and religious facilities.

Differentiator

Problem solved

Functional benefit

Products and services

• Structural Engineering & Design Delivers safe, efficient, and code-compliant structural designs across wood, steel, concrete, CMU, and tilt-up systems tailored to meet project goals from concept through construction. Serves architects, contractors, developers, and building owners on commercial, residential, mixed-use, and institutional building projects.
• Remodel & Adaptive Reuse Provides structural design solutions for renovations, seismic retrofits, and adaptive reuse projects that bring aging structures up to current codes and performance standards. Targeted at owners of older buildings, including historic and non-ductile structures in California.
• Permit-Ready Documentation Prepares complete structural calculation sets and construction drawings ready for submission, review, and approval, ensuring smooth permit processes and compliance with all regulatory requirements. Used by architects, contractors, and developers to support permit approval for new construction, remodel, and adaptive reuse projects.

Quantifiable outcome

• 5,000+ projects delivered since 1989
• +1 more outcomes

Named customers13 records

Segments3 records

Ideal customer profiles3 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature4 records

Partnerships

Four partnerships are on record, tiered core.

• PLUS ArchitectscoreStrategic or Co-development PartnerLee & Lee collaborated with PLUS Architects on the Fairfax Apartments project at 731 N. Fairfax Ave., Los Angeles, providing structural engineering to support a modern multi-residential development with advanced materials and engineering techniques. Also partnered on the vine 901 mixed-use project at 901 Vine St., Los Angeles.
• Corbel ArchitectscoreStrategic or Co-development PartnerCorbel Architects is a recurring project partner across multiple Lee & Lee projects including OnBeach Medical Center & Senior Residence (5832 Beach Blvd., Buena Park), Yaya Vanowen 101-unit Apartments (Los Angeles), Lankershim Apartments (Los Angeles), 731 Oxford (Los Angeles), and ARCHWOOD Apartment (Van Nuys). The firm provides architectural design while Lee & Lee delivers structural engineering.
• Group ArchcoreStrategic or Co-development PartnerLee & Lee partnered with Group Arch on the Star Express Car Wash facility (Bellflower, CA), the 2545 W. Olympic mixed-use development (Los Angeles), and the La Puente 30-unit mixed-use building, providing structural design to support Group Arch's architectural vision.
• Birba GroupcoreStrategic or Co-development PartnerLee & Lee collaborated with Birba Group on the El Nuevo Amanecer 61-unit affordable apartment complex in Los Angeles, providing structural engineering solutions to ensure long-term durability and compliance with contemporary building codes.

Scale indicators3 records

Recent moves5 records

Expansion highlights5 records

Direct peers

• John A. Martin & Associates: Los Angeles-based structural engineering firm serving commercial, healthcare, education, and residential developments across the Western U.S. Comparable to Lee & Lee in California-centric structural consulting with seismic and large-building capabilities.
• Holmes Structures: San Francisco-based structural engineering firm with West Coast presence spanning new construction, seismic retrofit, and adaptive reuse — directly comparable to Lee & Lee's seismic retrofit and adaptive reuse specialization in California.
• DCI Engineers: West-Coast-rooted structural engineering consultancy with offices across the U.S., serving multifamily, commercial, healthcare, and educational projects. Comparable in multi-material design capability and multi-story wood-frame expertise relevant to Lee & Lee's multifamily portfolio.
• MHP Structural Engineers: Los Angeles-headquartered structural engineering firm focused on residential, commercial, and healthcare projects with seismic expertise. Comparable in size, geography, and building-type mix to Lee & Lee.
• Nishkian Menninger: California structural engineering consultancy with offices in Los Angeles and the Bay Area, serving residential, commercial, and healthcare projects. Comparable multi-material scope and West-Coast market focus.
• Englekirk Structural Engineers (IDS Group): Southern California-headquartered structural engineering consultancy with deep multi-material and seismic expertise across commercial, residential, and institutional projects — the closest direct peer to Lee & Lee by geography, service mix, and project typology.

Broad incumbents

• Simpson Gumpertz & Heger (SGH): National structural engineering consultancy with established expertise in building structures, seismic engineering, and forensics. Larger and broader than Lee & Lee but competes for similar seismic retrofit and complex structural assignments.
• Walter P Moore: National engineering firm with a strong structural engineering practice covering healthcare, sports, and civic projects. Competes with Lee & Lee in larger structural commissions and seismic engineering consulting.
• Martin/Martin Inc. Multi-office structural engineering firm with residential, commercial, and healthcare expertise. Overlaps with Lee & Lee's multi-material scope and multi-story wood-frame project typology.
• Thornton Tomasetti: Global structural engineering consultancy with deep seismic, retrofit, and high-rise expertise. Operates at a larger scale than Lee & Lee but competes in the same structural consulting category for complex California projects.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat3 records

Key risks5 records

Key highlights6 records

Customer concentration

Compliance1 record

Revenue estimate

Valuation estimate

Number of profiles

Profiles1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about LEE & LEE STRUCTURAL ENGINEERING INC