At GBK, we work in our clients’ best interest and provide educated, professional and ethical service. We build relationships based on honest dialogue and responsiveness.

We respect, value and serve not only our clients, but also our co-workers, owners, competitors and our community. We’re concerned about and contribute to the well-being of those we serve, and operate with integrity so we can be deserving of their trust.

We provide a professional work environment that encourages openness, creativity, self-discipline and growth. An environment that acknowledges diversity as a source of richness. One that values each person’s contribution and promotes unselfish cooperation.

As a team or individually, we devote a portion of our time, talents and resources to the community, human needs, the arts, education and the environment.




In 1978, five experienced brokers came together to form a boutique real estate company in Seattle’s Eastlake neighborhood. The original partners named the firm Metcalf, Beattie & Knapp. They soon grew, welcoming additional brokers and independent-minded partners, never changing their core policy of putting clients first.  

In 1981 the company moved to Capitol Hill, purchasing the mid-century building on the corner of 13th and Pine. The location is in one of the city’s most dynamic communities and is centrally located to all Seattle neighborhoods. Now known as Gerrard Beattie & Knapp, or GBK, they continue to provide their clients with exceptional service. 

As Seattle’s premier independent real estate brokerage, GBK’s partners and brokers have a depth of local market expertise gained through decades of experience. And they have never strayed from working in every clients’ best interest through a steadfast focus on personalized attention.


GBK’s owners, Mark Potvin, Presha Sparling, Fionnuala O’Sullivan, and Nan Kinnier share the same core philosophy of always working in their clients’ best interest. They have a long-term perspective that is a client rather than transaction-based. As working broker-owners, they have a unique “hands-on” approach that is invaluable in deftly responding to changing markets and providing thoughtful counsel to all associate brokers and clients. With well over a century of collective experience, they have built a brokerage that is focused on transparency, ethics and a philosophy that all brokers, buyers and sellers deserve attention and care.

Mark's signature

Mark Potvin 

Presha's signature

Presha Sparling 

Fionnuala's signature

Fionnuala O’Sullivan 

Nan's signature

Nan Kinnier 


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Every broker at GBK is a REALTOR®. “REALTORS aren’t just agents. They’re professional members of the National Association of REALTORS® and subscribe to its strict code of ethics.” -NAR