Starr Electric Company, Incorporated in North Carolina, we significantly improved our electrical off-site construction capabilities and offerings and will continue to invest in the improvement of these offerings. Although complex modular construction is a small percentage of our current revenue, we believe that it is ripe for investment and growth and that it helps us to sell work and improve outcomes across our businesses.
Service Growth Initiative—Over the last several years we have made substantial investments to expand our service and maintenance revenue by increasing the value we can offer to service and maintenance customers. We are actively concentrating managerial and sales resources on training and hiring experienced employees to sell and profitably perform service work. In many locations we have added or upgraded our capability, and we believe our investments and efforts have provided customer value and stimulated growth in all aspects of our businesses.
Seek Growth through Acquisitions—We believe that we can further increase our cash flow and operating income by continuing to opportunistically enter new markets or service lines through acquisition. We have dedicated a significant portion of our cash flow on an ongoing basis to seeking opportunities to acquire businesses that have strong assembled workforces, excellent historical safety performance, leading design and energy efficiency capabilities, attractive market positions, a record of consistent positive cash flow, and desirable market locations.
Operations and Services Provided
We provide a wide range of construction, renovation, expansion, maintenance, repair and replacement services for MEP and related systems in commercial, industrial and institutional properties. Our local management teams maintain responsibility for day-to-day operating decisions. Local management is augmented by regional leadership that focuses on core business competencies, regional financial performance, cooperation and coordination between locations, implementing best practices and corporate initiatives. In addition to senior management, local personnel generally include design engineers, energy efficiency and sustainability experts, sales personnel, customer service personnel, installation and service technicians, sheet metal and prefabrication technicians, estimators and administrative personnel. We have centralized certain administrative functions such as insurance, employee benefits, training, safety programs, marketing and cash management to enable our local operating management to focus on pursuing new business opportunities and improving operating efficiencies.
Construction and Installation Services for New Buildings—Our installation business related to newly constructed facilities, which comprised approximately 45.9% of our consolidated 2019 revenue, involves the design, engineering, integration, installation and start-up of MEP and related systems. We provide “design and build” and “plan and spec” installation services for office buildings, retail centers, manufacturing plants, healthcare, education and government facilities and other commercial, industrial and institutional facilities. In a “design and build” installation, we work with the customer to determine the needed capacity and to optimize energy efficiency of the MEP systems that best suit the proposed facility. The final design, terms, price and timing of the project are then negotiated with the customer or its representatives, after which any necessary modifications are made to the system plan. In “plan and spec” installation, we participate in a bid process to provide labor, equipment, materials and installation based on the end user’s plans and engineering specifications.
Once an agreement has been reached, we order the necessary materials and equipment for delivery to meet the project schedule. In many instances we fabricate ductwork, conduit and piping and assemble certain components for the system based on the mechanical drawing specifications. Finally, we install the systems at the project site, working closely with the owner or general contractor. Our average project takes six to nine months to complete, with an average contract price of approximately $822,000. We also perform larger project work, with 761 contracts in progress at December 31, 2019 with contract prices in excess of $1 million. Our largest project in progress at December 31, 2019 had a contract price of $97.2 million. Project contracts typically provide for periodic billings to the customer as we meet progress milestones or incur cost on the project. Project contracts in our industry also frequently allow for a small portion of progress billings or contract price to be withheld by the customer until after we have completed the work. Amounts withheld under this practice are known as retention or retainage.
Renovation, Expansion, Maintenance, Monitoring, Repair and Replacement Services for Existing Buildings—Our renovation, expansion, maintenance, monitoring, repair and replacement services in existing buildings comprised approximately 54.1% of our consolidated 2019 revenue. Maintenance and repair services are provided either in response to service calls or under a service agreement. Service calls are coordinated by customer service representatives or dispatchers that use computer and communication technology to process orders, arrange service calls, dispatch