About Seal Harbor Companies

Seal Harbor Companies is a family owned business operating in Massachusetts and Southern Maine. The company is comprised of talented management staff that bring your dreams to reality!

Mark M. Gallagher is the founder and senior manager of the companies. As a developer and builder, he has been developing land and constructing homes in the New England area since 1982. A graduate from Suffolk University, Mark began in this industry first by designing his own home shortly before being married in 1981. After overseeing the construction of our new home, he began developing land and constructing homes in the Acton, Concord and Lexington area. Throughout the next 25 years, he has continued to build homes in these areas as well as Maynard, Carlisle and Westford, Massachusetts.

In the mid-80s, the business expanded to include construction in New Hampshire and Maine. My experience allowed me to expand the business into design/build as well as commercial construction such as office buildings and small resorts.

In the 90s, my construction business evolved to focus solely on commercial construction, including the design and installation of fire suppression systems and construction in larger commercial buildings. Major customers included Irving Oil, AT&T, Exxon Mobil and the United States Government.

Since 2001, my company has enjoyed an office in both Massachusetts and Maine.

Mark P Gallagher is the vice president and manager of Seal Harbor. Mark has been involved in the development and construction business since his graduation from college in 2016. Mark attended Bryant College in Smithfield, Rhode Island and graduated with a degree in accounting and a minor in law. Mark is married and has two wonderful growing children. Mark manages our offices in Massachusetts and also manages the daily scheduling and all of the permitting required to run our business.

Kayla N Gallagher recently joined our business. Kay graduated from Wentworth University in Boston in 2017 with a degree in Interior Architecture. Kay works with us with customer management. She is also responsible for the design of the floor plan changes and construction elements of our single family homes. Kay works closely with our customers providing renderings and guidance through their selection process. Kay also manages our Design Center in Massachusetts.

Patrice M Gallagher, Mark Senior’s wife, manages the accounting group in our business. Patrice is a graduate from Saint Anselm College in Manchester New Hampshire. Patty manages our bookkeeping group and ensures our business including cash management and purchasing of our goods flows freely to ensure our construction schedule moves forward on any given day.

Throughout the years, Seal Harbor has offered the following services:

  • Restoration and remodeling – Restored several “period” homes from as early as 1735 through the late 1800s
  • Development – Purchase land and plan developments from permitting and consulting through road construction
  • New homes – Design and build of new homes from 400 square feet to over 10,000 square feet
  • Commercial – Construction of hotel units and cottages as well as commercial buildings
  • After care – Care of your home or investment after the sale

The following are developments by State consisting of 1 to 250 homes within the property.



  • Anthem Villages, Acton
  • Preserve at Audubon Hill, Acton
  • Crane’s Crossing, Ayer
  • Bennett Orchards, Littleton
  • Wildflower Meadows, Littleton
  • Freedom Farm, Acton
  • Lady Slipper Lane, Acton
  • Wampanoag Drive, Acton
  • Larch Road, Acton
  • Evergreen Road, Acton
  • Mocking Bird Lane, Maynard
  • Sutton Place, Acton
  • Stoneymead Farm, Acton
  • Strawberry Hill Road, Acton
  • Mattison Drive, Concord
  • Channing Road, Concord
  • Ayshire Road, Concord
  • Macmillan Drive, Concord
  • Arrowhead Farms, Concord
  • Old Marlborough Road, Maynard
  • Pine Meadows, Maynard
  • Pine Ridge Meadows, Acton
  • Tatnic Road, Wells
  • Seal Harbor Condominiums and Homes, Wells
  • Atlantic House, Wells
  • Holiday House, Moody
  • Perry Oliver Road, Wells
  • Red Coat Lane, Wells
  • Oqunquit House
  • The Homes at 293 Main Street Ogunquit
  • Beach Dreams, Post Road Wells
  • Sea Oaks, Ogunquit
  • The Heights, Ogunquit
  • Barefoot Cottage Homes, Wells
  • The Compass Pointe Club, Wells
  • Topsail Homes, Wells
  • Ocean Mist Village, Wells