AmGen Builders

AmGen Builders is the general contracting arm of the AmGen Group, providing comprehensive construction services across California, Hawaii, and Utah. With over 35 years of experience in the industry, we have built a wide array of residential, commercial, and hospitality properties.

Our current focus is on:

Commercial Tenant Improvements (T.I.)
Multi-Family Residential
Hospitality
Senior and Assisted Living Communities

Our methodology is designed to deliver results that exceed expectations while staying on budget and on schedule. Over decades of successful projects, we have refined an approach that provides our partners and project owners with reliable, transparent, and high-quality outcomes.

Our Approach

Our construction methodology is organized into three key phases, which also form the main groups of services we offer.

Pre-Construction

During this phase, we focus on planning and preparation to ensure projects are feasible, cost-effective, and constructible. Services include:

Provide budget estimates
Advise on means & materials
Implement value engineering
Conduct constructibility reviews
Compare cost options
Facilitate green building requirements

Construction

Our construction phase emphasizes precise management and coordination, ensuring quality and safety at every stage. Services include:

Site project management
Contractor procurement and coordination
Safety management
Move management and relocations
Document control
Develop and implement strategies for unique site conditions

Post-Construction

After the build is complete, we ensure every project is fully operational and meets all compliance requirements. Services include:

Punch list management
Provide Maintenance & Operations (M&O) manuals
Oversee start-up procedures
Obtain final inspections and Certificates of Occupancy
Compile closeout documentation
Provide in-house warranty services

At AmGen Builders, we are committed to delivering excellence in every project, from pre-construction planning through post-construction support.

Case Study: GST HQ Expansion – Cerritos, CA

When GST (Golden Star Technologies) needed to grow its Cerritos headquarters for the next chapter of its business, they needed more than a contractor. They needed a builder who could expand a fully operational campus — on schedule, without interrupting a single day of business — and deliver a facility worthy of a 40-year company milestone.

AmGen Group delivered a $9,000,000, 50,000 sq. ft. expansion that added tilt-wall warehouse capacity, a purpose-built technology integration floor, and a fully reimagined lobby — all while GST’s team worked, shipped, and served customers around them.

The project was completed in time for GST’s 40th anniversary grand re-opening in August 2024, an event recognized by the City of Cerritos as a landmark economic development milestone.

SCOPE OF WORK

50,000 sq. ft. tilt-up concrete warehouse addition
Full site work: grading, paving, utilities, and fire-lane circulation
High-rack industrial shelving and logistics infrastructure
10,000 sq. ft. computer, AV integration, and product staging area with specialized power, data, and environmental systems
Complete lobby remodel with upgraded reception and employee amenities
Executed on a fully active, operating campus with zero business interruption

Project Significance

Occupied-facility construction is one of the most demanding categories in commercial building. There is no margin for schedule slippage, no tolerance for disruptions that affect the client’s operations, and no second chances with a 40-year company’s anniversary on the calendar. AmGen delivered on all counts — on time, within budget, and with a client ready to put their name and logo behind us.

For owners and developers evaluating a general contractor for an industrial, flex, or technology-integrated facility in Southern California, the GST project represents exactly what AmGen brings to the table: boutique-firm accountability with the experience and subcontractor relationships to execute complex work at scale.