Daytime view of a marina in Hawaii

Ameresco Welcomes Chelsea Group Limited

After more than 25 years of preserving and enhancing the mechanical infrastructure in existing commercial office, institutional, retail, and industrial facilities, Chelsea Group Limited has joined the Ameresco team.

Together our building scientists and engineers solve problems and find opportunities that add asset value to facilities. The application of good science and engineering to existing buildings allows us — and you — to take into account the whole facility, as well as its complex parts.  Working together to implement our recommendations, we can achieve a balance of performance, comfort, and aesthetics, resulting in greater property value and productivity.

Our Offerings

Providing customers throughout Hawaii with assessment, design, construction project management, commissioning, and Sustainability & Performance Certification.


Assessment: Knowledge brings value and power to building owners, managers, and operators.  Our team’s in-depth analysis offers insight and provides real solutions for challenges and opportunities in your building.  We conduct PCAs — Property Condition Assessments — as well as energy & IAQ audits, and CapEx planning, providing the vital knowledge necessary to make good financial and operational decisions.

Design: Implementing recommendations within an existing building often requires custom design for major infrastructure improvements, such as chiller replacement or air handler replacement.  Our engineers conduct detailed site investigations to determine existing conditions, updating or creating as-built drawings.  Combining knowledge of technology options with our comprehensive understanding of site conditions, our team — working closely with the owner to review and approve designs at each stage — develops cost-effective infrastructure improvements.  Following full approval, our engineers prepare construction documents for use in the procurement process.  These high-quality bid documents result in well-tuned contractor proposals.

Construction Management: The high-quality construction documents produced by our design team provide an effortless hand-off to our construction management team. Our professionals prequalify appropriate contracting resources with the owner, assist in bid solicitation, and recommend the best resources for the project. From pre-bid to selection, our team focuses on quality and cost effectiveness. We chair the OEC — owner, engineer, contractor — meetings and actively track and guide construction through the challenges of existing conditions to achieve project goals.

Commissioning: Commissioning (Cx) is a process by which projects are tracked and measured — from beginning to end — against the owner’s goals and project specifications.  Our team develops an OPR — owner project requirements — and a BOD — basis of design — providing higher probability of an on-time, on-budget project.  Our commissioning agent starts reviewing a project at the onset of design and continues with field verification of contractor work throughout.  As the project construction nears completion, our team applies a systematic process of functional performance testing, resulting in demonstrable proof that the finished project meets owner’s expectations. Our commissioning agent documents the entire process — from design through start-up — to achieve the best result, reporting it all for the owner.

On-going Services: Existing buildings have a continuous need for maintenance, as well as verification of peak efficiency operation.  We provide owners with on-going support, enabling them to keep building systems operating correctly.  When performance lags, our building scientists select the appropriate actions, maintaining thorough documentation of building energy use trends.  Many of our clients have chosen to seek recognition for their on-going efforts through certifications of the performance of their buildings, such as:

  • LEED Certification from the US Green Building Council
  • Energy Star Certification from the US EPA
  • Energy Project of the Year awards from the Association of Energy Engineers


Square Feet of LEED Certification


ENERGY STAR Certifications


Client Buildings


Hawaii Energy Rebates


Central Plant Improvement: Repair or replace?  Like-for-like or upgrade the technology?  Our experienced engineers can guide you through the decision process and then design, manage, and commission everything from a minor pump change to a full central plant replacement.

Mechanical Infrastructure Needs: Heart and lungs – central plant and air handlers; veins and arteries – air and water supply and distribution; brain. nerves and muscles – building automation and control – the infrastructure of a building holds it up and makes it work.  Be done with band-aids on problems to hide symptoms.  Our building scientists can help you look at the whole picture, then plan and implement solutions.

Property Condition Assessment: Transaction support?  Market repositioning?  Capital planning?  A substantial part of the fundamental value of a property – the part that doesn’t rely on location – depends on the age and condition of the infrastructure of the building.  Our engineers and building scientists aid your property team – owners, asset managers, and property managers – in evaluating the condition of that infrastructure and developing multi-year cap ex plans that match your needs.

Indoor Air Quality Management: Breathe easier?  Happier more productive occupants?  Temperature, odor, and respiratory issues top the list of reasons tenants complain about building operations.  Our building science teams understand the root causes and the best management practices for these concerns and pair them with efficient solutions for outcomes that please both landlords and tenants.

LEED & Energy Star Certifications: Market positioning credential?  Proof of superior facility management performance?  Energy Star Certification has become de rigueur in many commercial real estate markets today.  LEED Certification is a prerequisite for the US Government and many top corporate tenants.  Our Professional Engineers and LEED Accredited Professionals can guide you to success in both certifications.

Building Automation Optimization: See inside machinery?  Make all the parts sing harmony?  Building automation has progressed nearly apace with computer technology and software advancements, giving you unprecedented data and potential control of mechanical infrastructure.  Our engineers and commissioning agents can set up the best monitoring and control strategies and turn that raw data into information and control to optimize your plant.

Distribution Investigation: Clogged arteries?  Leaking valves?  Aging buildings, like aging people, may have a buildup of dust and debris in supply and exhaust ducts, chilled and hot water lines, or basic water and sewer lines.  Using a range of diagnostic tools including robotic probes, fiber optic snakes, ultrasonic flow measurement, and ground penetrating radar, our building scientists can peer into the unknown depths and recommend and specify efficient solutions to distribution challenges.

Building Energy Planning: Cut cost?  Prove your operational efficiency?  Benchmarking energy use and plant operations, then developing a systematic plan to manage energy demonstrates your facility management skill.  Our energy engineers can audit your facility and set up Energy Star and advanced benchmarking tools – and set up multi-year cap ex programs to match your needs.

Featured Projects

Daytime view of a valley in Hawaii bordered by jagged mountains

The Queen’s Medical Center – Award-Winning Central Plant Optimization

The Queen’s Medical Center retained Chelsea Group in a series of central plant studies that began in 2008 and culminated in the Retro-commissioning and Central Plant Optimization. The net result was an annual saving rate that totals 687,013 kWh, which equates to electrical bill savings of $197,68, winning the project Energy Project of the Year Award 2015 for Region V by the Association of Energy Engineers.

Daytime view of a rocky beach on a Hawaiian island

Pearlridge Mall – Award-Winning Central Plant Replacement

Chelsea Group helped achieve 54% energy use reduction in the Pearlridge Mall with a complete central plant replacement, winning the project the 2016 Energy Project of the Year for Region V by the Association of Energy Engineers. Pearlridge was sold for a 100% return on investment, reflecting improved value from new mechanical infrastructure.