Custom Homes, Remodels, and Commercial Construction in Mercer Island, WA

Gallagher Co. handles three types of work: custom homes, remodels, and commercial projects. Based in Mercer Island, we serve neighborhoods across the Puget Sound region, including Greater Seattle and the Eastside.

We are not a volume contractor. We take on projects where the complexity and expectations match what our team does best. If you are building, renovating, or developing something that needs to be done right, look no further and see what we can do for you.

Custom Homes

New construction designed for your lot, your lifestyle, and the way you want to live. We take projects from initial planning through move-in, coordinating with your architect and design team at every stage.

Remodels

Renovations for homeowners who expect the same level of precision and accountability as a new build. Whether it is a single floor or a full gut, we treat every remodel as a complete project, not a side job.

Commercial

Tenant improvements, office buildouts, and ground-up commercial construction with the scheduling discipline and site management standards we built our reputation on.

Why Clients Choose Gallagher Co.

There are a lot of builders on the Eastside. Here is what makes working with us different.

We are local.

With roots in Mercer Island, we know the permitting process, the subcontractor relationships, and the site conditions all across the shorelines of the Puget Sound region and Greater Eastside. We are not entering this market from a distance, we have a long history here.

We manage projects, not just builds.

Communication, scheduling, and budget management are built into how we work. You get proactive updates, honest timelines, and a team that takes accountability for the outcome.

The work speaks for itself.

Two decades of completed custom homes, remodels, and commercial projects across the Eastside. Recognized by Luxe Magazine and the Puget Sound Business Journal for both quality and growth.

We are selective.

We do not take on every project. We take on the ones where our capabilities match what the project demands. That is better for you and for us too.

Ready to Talk About Your Project?

Whether you are planning a custom home, a full renovation, or a commercial buildout, we would like to hear about it.