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Private Developer-Focused Construction Leadership

Build with Certainty.
Deliver with Trust.

A cost-certain, schedule-driven construction firm — general contracting, construction management, and owner representation for owners and developers who value clarity, accountability, and disciplined execution.

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30+PROJECTS DELIVERED
27+YEARS IN CONSTRUCTION
5SERVICE LINES
CA + COLicensed & Historic-Certified
✓Cost-Certain Pricing✓Schedule-Driven Delivery✓Owner's-Rep Perspective✓Licensed in CA & Aspen, CO
What We Stand For
Our Values
01

Good Fit Matters

We work with people who value honesty, accountability, respect, and teamwork.

02

No Surprises. Solve It Early.

We communicate early, clearly, and directly.

03

Own the Outcome

We take personal responsibility for results.

04

Finish Strong

We bring the same discipline to closeout that we bring at the start.

How We Deliver
Services

Preconstruction-Led Delivery. Hands-On Project Leadership.

General Contracting

  • Preconstruction & budget development
  • Tenant improvements
  • Facility upgrades & renovations
  • Ground-up & site-based construction

Construction Management

  • Delivery planning & procurement
  • Budget, cost & schedule control
  • Field oversight & quality assurance

Owner Representation

  • Owner-focused project leadership
  • Developer-focused coordination
  • Reporting & decision support

Alternative Dispute Resolution

  • Mediation & neutral services
  • Expert analysis & testimony
  • Claims & dispute consulting

Industrial & Logistics

  • Warehouse, distribution & logistics facilities
  • Tilt-up & pre-engineered structures
  • Industrial-park TIs, repaints & upgrades
  • Process piping & central plant systems
Specialized Expertise
Complex, critical, code-intensive construction.
🏥

Healthcare & Medical

Occupied hospitals, correctional-medical, and treatment facilities where infection control, life-safety, and 24/7 uptime are non-negotiable.

🧪

cGMP · Pharma & Biotech

Cleanrooms, controlled environments, and validation-ready manufacturing built to exacting regulatory standards.

🔬

High-Tech & Laboratories

Advanced facilities and lab build-outs demanding precision, cleanliness, and specialized MEP systems.

❄️

Central Plants & Mechanical

Central chilled-water plants, thermal energy storage (TES), and large-scale HVAC modernization.

🔧

Plumbing & Process Piping

Building, process, and life-safety piping executed in critical, occupied environments.

🏢

Large-Scale Multifamily

Ground-up multifamily at scale, including delivery of a 465-unit apartment community.

Selected Work
Projects

Multifamily, luxury residential, industrial & logistics, commercial, and civic work across the West and beyond. Click a highlighted project for the case study.

Charlmont Village Apartment ADU'sMultifamily

Charlmont Village Apartment ADU's

📍 Ontario, California

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Broadview ApartmentsMultifamily

Broadview Apartments

📍 San Bernadino, CA

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Ridgeline ApartmentsMultifamily

Ridgeline Apartments

📍 San Bernadino, CA

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Meredith Lake HouseLuxury Residential

Meredith Lake House

📍 Meredith, NH

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Twin Towers Elevator ReplacementCivic / Correctional

Twin Towers Elevator Replacement

📍 Los Angeles, CA

View case study →
Century Regional Detention FacilityCivic / Correctional

Century Regional Detention Facility

📍 Lynwood, CA

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SWORD Logistics CenterIndustrial / Logistics

SWORD Logistics Center

📍 Tulsa, OK

View case study →
Principal’s Background
Prior Leadership Experience

Projects Ryan Dumoulin led in senior roles at previous firms — individual credentials of key personnel, not Seamline Pacific Builders, Inc. company past performance.

Sunset + Vine TowerHigh-Rise / Mixed-Use

Sunset + Vine Tower

📍 Hollywood, CA

★ Project Executive · Prior firm

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USC Galen CenterSports / Arena

USC Galen Center

📍 Los Angeles, CA

★ Project Executive · Prior firm

View project →
5600 WilshireMultifamily

5600 Wilshire

📍 Los Angeles, CA

★ Project Manager · Prior firm

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NRDC — Robert Redford BuildingCommercial

NRDC — Robert Redford Building

📍 Santa Monica, CA

★ Project Manager · Prior firm

View project →
Doheny Eye InstituteHealthcare / Medical

Doheny Eye Institute

📍 Pasadena, CA

★ Project Executive - Mechanical Contractor · Prior firm

View project →
Kaiser Permanente South Bay Medical CenterHealthcare / Medical

Kaiser Permanente South Bay Medical Center

📍 Santa Ana, CA

★ Project Management · Prior firm

View project →
EVOQ Properties OfficesCommercial

EVOQ Properties Offices

📍 Los Angeles, CA

★ Prior firm

View project →
Santa Monica College — AET CampusHigher Education

Santa Monica College — AET Campus

📍 Santa Monica, CA

★ Project Executive - Mechanical Contractor · Prior firm

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LAX — Security Systems IntegrationAviation

LAX — Security Systems Integration

📍 Los Angeles, CA

★ Project Management · Prior firm

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CSU Long Beach — Central PlantHigher Education

CSU Long Beach — Central Plant

📍 Long Beach, CA

★ Project Executive - Mechanical Contractor · Prior firm

View project →
CSU Dominguez Hills — Science & Innovation BuildingHigher Education

CSU Dominguez Hills — Science & Innovation Building

📍 Carson, CA

★ Project Executive · Prior firm

View project →
CSU Dominguez Hills — Innovation & Instruction BuildingHigher Education

CSU Dominguez Hills — Innovation & Instruction Building

📍 Carson, CA

★ Project Executive - Mechanical Contractor · Prior firm

View project →
CSU San Bernardino — Central PlantHigher Education

CSU San Bernardino — Central Plant

📍 San Bernardino, CA

★ Project Executive - Mechanical Contractor · Prior firm

View project →
Pierce College — Advanced Automotive Technology BuildingHigher Education

Pierce College — Advanced Automotive Technology Building

📍 Woodland Hills, CA

★ Project Executive - Mechanical Contractor · Prior firm

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Pierce College — Central PlantHigher Education

Pierce College — Central Plant

📍 Woodland Hills, CA

★ Project Executive - Mechanical Contractor · Prior firm

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Cabrillo High School (LBUSD)Higher Education

Cabrillo High School (LBUSD)

📍 Long Beach, CA

★ Project Managment · Prior firm

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LAUSD — Multiple Projects (13 total)K-12 Education

LAUSD — Multiple Projects (13 total)

📍 Los Angeles, CA

★ Project Manager · Prior firm

View project →
Positioning
A builder’s discipline. An owner’s perspective.

A cost-certain, schedule-driven construction firm — general contracting, construction management, and owner representation for owners and developers who value clarity, accountability, and disciplined execution.

Answers
Frequently Asked Questions
We provide general contracting, construction management, and owner representation for owners and developers — a cost-certain, schedule-driven approach from preconstruction through closeout.
We serve owners and developers across California, headquartered in Westminster. Reach out with your location and we'll confirm fit.
Yes. Seamline Pacific Builders holds California Contractors License #1153483 and CA DIR registration #2000028522, and carries full commercial insurance.
Multifamily and apartments, ADUs, commercial and institutional work, tenant improvements, and owner's-representation engagements. See our Projects for representative work.
Request a consultation below or email us. We'll bring a builder's read on your project and a cost-certain plan for delivering it.
Get In Touch
Start a Project
📍6152 Camphor Ave, Westminster, CA 92683
📞(714) 307-8345
✉️Ryan@SeamlinePacific.com
🪪CA Contractors License #1153483 · CA DIR #2000028522
City of Aspen / Pitkin County Unlimited License #UC-000382 · Aspen HPC Historic Specialty Certified
👤Ryan Dumoulin, President
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