McCullough Architects is located in Georgetown, an energetic neighborhood in south Seattle. We are a full service design firm serving clients in a broad range of project types including custom homes and mixed use buildings. We believe that by integrating architecture and planning in our design process we create solutions of greater value to our clients. Our creativity, attention to detail, and varied experience results in exceptional service and a growing family of satisfied clients.

Founded in 1992 by Greg Hackworth as Hackworth Architecture and Planning, the firm has provided design services for a variety of clients for over twenty years. Originally located in downtown Seattle near Pike Place Market, we have worked with developers, builders, and owners to create projects including large single family developments, multi-family buildings, and custom single-family homes.

In 2010 Philip McCullough, an employee since 1996, purchased the company. Since then, the firm has expanded the range of projects to include mixed-use and commercial with a special focus on custom homes and multi-family projects. In August of 2013, the company became McCullough Architects. Now located in the Georgetown neighborhood, McCullough Architects looks ahead to continued service to our valued clients.

McCullough Services


McCullough Architects has a large body of past and current custom residential work. We provide custom residential design services for both individual clients and home builders.


Our services for single-family home builders include land planning, spec-home design, neighborhood design, and infill housing as well as design review services for more complex projects.


Our attached homes include duplexes, townhomes, stacked flats, and mixed-use buildings. We also provide associated land planning services and design documents for the entitlement process.


From shell-and-core work for our developer clients, to tenant improvement build-outs for tenants and owners, we provide innovative solutions to commercial mixed-use projects. Many of our commercial projects incorporate a residential component into a mixed-use project.


We provide a full range of land planning services including master planning for long term projects of different sizes and scopes. We have worked with both local developers and national developers.