Build with certainty. Deliver with trust.
Preconstruction-led general contracting, construction management and owner representation for owners and developers.
- California
- Contractors License #1153483
- California DIR
- Registration #2000028522
- City of Aspen / Pitkin County
- Unlimited License #UC-000382
- Aspen HPC
- Historic Specialty Certified
One team from first budget to turnover.
Estimator-to-execution continuity: the people who price your project are the people who build and close it.
30 years in construction. 50+ projects delivered. Building in California, Colorado (Aspen), Arizona, Oklahoma and New Hampshire.
General contracting
Preconstruction and budget development, tenant improvements, facility upgrades and renovations, ground-up and site-based construction.
Construction management
Delivery planning and procurement, budget, cost and schedule control, field oversight and quality assurance.
Owner representation
Owner-focused project leadership, developer-focused coordination, reporting and decision support.
Industrial and logistics
Warehouse, distribution and logistics facilities. Tilt-up and pre-engineered structures. Industrial-park TIs, repaints and upgrades. Process piping and central plant systems.
Alternative dispute resolution
A builder's read on the record, for counsel who need analysis that holds up: mediation and neutral services, expert analysis and testimony, claims and dispute consulting.
Preconstruction
Conceptual estimating, budgeting and strategy. Value engineering, scope alignment and bid packaging, with clear assumptions before a shovel moves.
Execution
Trade partner sourcing, bid leveling and buyout. Scheduling, phasing and occupied-site planning. Hands-on field oversight throughout.
Closeout
Contract administration and closeout by the same team that priced the work, through turnover.
What we stand for
- Good fit matters
- We work with people who value honesty, accountability, respect and teamwork.
- No surprises. Solve it early.
- We communicate early, clearly and directly.
- Own the outcome
- We take personal responsibility for results.
- Finish strong
- We bring the same discipline to closeout that we bring at the start.
Selected work
Century Regional Detention Facility
A comprehensive replacement of the fire-alarm system and elevators at an LA County jail housing ~2,150 inmates — executed inside a fully operational, high-security correctional environment. Delivered to a 14-month schedule while meeting Project Labor Agreement and prevailing-wage requirements, without taking the facility offline.
- Lynwood, CA
- 426 days (14 months)
- PLA and prevailing-wage compliant
Twin Towers Elevator Replacement
Civic / Correctional, Los Angeles, CA
SWORD Logistics Center
Industrial / Logistics, Tulsa, OK
Meredith Lake House
Luxury Residential, Meredith, NH
Ridgeline Apartments
Multifamily, San Bernardino, CA
Broadview Apartments
Multifamily, San Bernardino, CA
Charlmont Village Apartment ADU's
Multifamily, Ontario, California
500 West Francis Street
Luxury Residential, Aspen, Colorado
406 West Smuggler Street
Luxury Residential / Historic, Aspen, Colorado
Lower Buckeye
Industrial / Logistics, Phoenix, Arizona
Senior people on every job.
The leadership team works the project directly, not through layers.
“He doesn’t just manage a project; he owns it.”
Ryan Dumoulin
President
Bill Lee
Project Executive
Quentin Johns
Chief Financial Officer
Questions owners ask
What does Seamline Pacific Builders do?
We provide general contracting, construction management, and owner representation for owners and developers, with a cost-certain, schedule-driven approach from preconstruction through closeout.
Where do you work?
We are headquartered in Westminster, California, and licensed there and in Aspen / Pitkin County, Colorado. We also take on work in Arizona, Oklahoma, and New Hampshire. Tell us your location and we will confirm fit.
Are you licensed and insured?
Yes. Seamline Pacific Builders holds California Contractors License #1153483 and CA DIR registration #2000028522, and carries full commercial insurance.
What types of projects do you take on?
Multifamily and apartments, ADUs, commercial and institutional work, tenant improvements, and owner's-representation engagements. See our projects for representative work.
How do we get started?
Request a consultation or email us. We will bring a builder's read on your project and a cost-certain plan for delivering it.
Start a project.
Tell us about your project. We will bring a builder’s read and a cost-certain plan.
- Office
- 6152 Camphor Ave, Westminster, CA 92683
- President
- Ryan Dumoulin
- Licenses
- CA Contractors License #1153483. CA DIR #2000028522. City of Aspen / Pitkin County Unlimited License #UC-000382. Aspen HPC Historic Specialty Certified.