Braintree’s Integrated Builders, a construction management, design-build and general contracting firm, has completed of a 13,000-square-foot interior office fit-up project at 300 Apollo Drive in Chelmsford.

The space will be occupied by Intersil Corp., a designer and manufacturer of high-performance analog and mixed-signal semiconductors.

Integrated Builders, which was hired by the landlord, Chelmsford Associates LLC, provided demolition, millwork, roofing, glass and glazing, drywall, ACT, flooring, painting, window treatments, fire protection, plumbing, HVAC and electrical, and other general contracting services.

Prior to the Intersil project, Integrated Builders completed several projects at 300 Apollo Drive, including a two-phase, 133,500-square-foot interior construction project for the corporate headquarters of Aspect Software, a customer service, collections, sales and telemarketing solutions provider.