Crafting Your Dream Home Into Reality

Seal Harbor Companies is a family-owned business serving Massachusetts and Southern Maine, specializing in turning visions into reality. With a talented management team and decades of experience, Seal Harbor has become synonymous with quality development and construction.

Mark M. Gallagher, founder and senior manager, has been a prominent developer and builder in New England since 1982. A graduate of Suffolk University, Mark’s journey began in 1981 when he designed and oversaw the construction of his own home. This sparked his passion for land development and home construction, particularly in the Acton, Concord, and     Lexington areas. 

Over the next 25 years, his expertise expanded to include building homes in Maynard, Carlisle, Westford, and beyond.

By the mid-1980s, Mark had extended the business into New Hampshire and Maine, offering services that range from residential development to design/build and commercial projects, including office buildings and boutique resorts. Seal Harbor Companies continues to be a leader in the New England construction industry, driven by a commitment to quality and innovation.