TGH Firm Principals

Turnbull Griffin Haesloop is an award-winning architecture firm established in 1997 by Mary Griffin and Eric Haesloop to continue William Turnbull Associates and honor William Turnbull Jr.’s commitment to designing buildings in the landscape. Stefan Hastrup became a principal in 2008 and the firm practiced in San Francisco until 2020 when Mary Griffin moved to a consulting role and Stefan Hastrup decided to pursue new options. Today the Berkeley, California studio is led by Eric Haesloop and focuses on the design of sustainable, site sensitive houses and consults on larger scale projects.

The architecture of Turnbull Griffin Haesloop is inspired by the specific characteristics of each site and each client. In the site design phase, we attend to topography, microclimate, solar orientation, vegetation, water resources, and fire resilience. Green building principles guide us, and we choose building materials that complement their settings. Often indoor/outdoor relationships are the genesis of TGH designs. The built projects reflect our concern with daylighting, details, and the craft of building. We carefully listen to the aspirations and requirements of our clients and respond to the site where we will be building to develop a design that enhances both the landscape and the lives of those who inhabit it.

The archives of 24 years of work designed by Turnbull Griffin Haesloop have been donated to the UC Berkeley Environmental Design Archives.