Our Consultants

In the course of a project, we often draw upon people with special expertise. We feel one of the hallmarks of an excellent architectural firm is knowing when and how to ask the right questions and get appropriate, timely and expert answers. The following is a list of the people we might call upon during the course of a project, along with their specialties.

landscape architecture

Linnea Ferrell Landscape Architect

Linnea Ferrell

Issaquah, WA

Linnea was a principal and partner at Berger Partnership (where she was employed for nineteen years) before going out on her own in 2000 or so. While at Berger she did the landscape for IslandWood, Magnuson Park, the Center for Urban Horticulture as well as numerous residential projects, including one fairly big project in Medina for the founder of a major local software company. Linnea has consulted for us on the Williams Home, the Harding Home, the Marshall Renovation, the van Roessel Renovation and Dog Wood Forest as well as the design of our own yard and the Multigenerational Passivhaus project. Her husband operates a landscape construction firm, and they often work together on projects.


Scott Mantz and Associates, Inc.

Scott Mantz

Seattle, WA

I’ve known Scott for 25+ years. We shared an office on a houseboat on Portgage Bay back when I first started up. He does beautiful work. He does both design and construction. Scott and Linnea went to University of Washington together back in the day, and I would say their approach and depth of experience are similar.


structural engineering

Carissa Farkas Structural Engineering

Carissa Farkas

Seattle, WA
Member, Northwest EcoBuilding Guild

I met Carissa through Passive House Northwest. She is the local expert on structural engineering for Passive House projects. Her first project with us was the Bonaparte Passivhaus Cabin in 2010. Since then she has done the engineering for the Sunset Hill Second Story Addition, preliminary structural consultation on Lakeridge Haus, engineering on a complicated facade renovation on North Capitol Hill, and the Multigenerational Passivhaus.


Sliderule Engineering Works

Andy Herrick

Auburn, WA

Andy provided structural engineering services on virtually all of our projects from 2003 through 2010 – including the Barbat-Harrison Green Roof Garage, the Harding Home, and the McBride-Prozzo Renovation and many others. Andy has taken the initiative in helping us push the structural envelope (as it were), resulting in the most resource-efficient implementations of structure in our projects possible.


mechanical systems, energy analysis, alternative energy systems

Systems West Engineers

Peter Reppe

Eugene, OR

Peter is a Certified Passive House Consultant. He is the only cPHc in the Northwest who is also a mechanical engineer and as such, can provide exactly the kind of system design input we need on our more complicated Passivhaus projects. He comes up to Seattle at least once a month. He did the mechanical engineering for the Multigenerational Passivhaus.


Ecotope, Inc.

Jonathan Heller

Seattle, WA

Ecotope Inc. is a consulting firm specializing in the design and evaluation of energy and resource conservation in the built environment. Active in this field since 1975, Ecotope has worked on literally thousands of projects around the country. They are nationally recognized for their design expertise and their strong commitment to high-quality technical analysis. Ecotope developed the WattSun program currently approved by the state of Washington to evaluate the effects of solar insolation and various building components on energy use and operating costs. We’ve worked with Ecotope in major ways on our feasibility study for an eco-resort at Monte Cristo, the Patterson Home in Sharingwood Co-housing, Lavender Farm, the Williams Home and the Sproull-Radke Green Roof Garage/Workshop.


civil engineering, greywater systems, composting toilets, living machines, bioremediation

Mayfly Engineering

Robin McKennon Thaler

Seattle WA
Member, US Green Building Council

Mayfly Engineering is a small, woman-owned civil engineering firm specializing in green civil strategies. A LEED accredited professional engineer, Robin’s unique natural resource background (a prior degree in forestry) brings an important focus on low-impact design to all of the projects to which she contributes. Robin is known for her creative design approach and solid technical base. She is often asked to participate in value engineering studies and design charrettes for both public agencies and private clients.  Robin has provided project management and design for dozens of site design projects and consultation and documentation for more than twenty LEED projects.  These projects include Cascade Playground–winner of the 2005 Washington State ACEC Gold Award for Social, Economic, and Sustainable Design Considerations–and The South Lake Union Discovery Center; where the pervious paver parking lot, bio-swale infiltration systems, rain gardens, and demonstration green streets replaced the need for conventional detention.  Robin also provided site related LEED consultation for Washington State’s Certified GOLD Tumwater Office Building. Though we have yet to officially work on a project together, I have been impressed with the depth of Robin’s knowledge and enthusiasm on the project proposals we have pursued.


Herrera Environmental Consultants

Chris Webb

Seattle, WA

Chris Webb is a professional engineer and a LEED™ Accredited Professional who is passionate about providing civil engineering designs that demonstrate the highest degree of sustainability and are based on ecological principles. Chris is a frequent speaker on the technical aspects of sustainability as it is applied in civil engineering. He was part of the design team on Islandwood, the first LEED™ Gold project in Washington State, and Chris has served as a member of the technical advisory group for the US Green Building Council’s LEED™ Rating System (Version 2.0). Chris and I have worked together on a feasibility study for a theater and eco-resort in the town of Monte Cristo, WA (it wasn’t feasible), and two projects with particularly challenging civil engineering, Lavender Farm and both sites of the Multigenerational Passivhaus.

materials and detailing, community design

Archemy Consulting, Ltd.

David Rousseau

Cortez Island, B.C.

Author of Healthy By Design, Environmental by Design, and Your Home, Your Health and Well-being, David Rousseau is arguably the most knowledgeable person in the Northwest when it comes to “green” materials and their specific uses. He is also an accomplished educator and community designer. Beyond the technical, he has an umatched depth of understanding of the spiritual aspects of building. I consider him my mentor and a dear friend. We first met in 1993 when I wrote a review of Environmental By Design for the EcoBuilding Times. David and I collaborated on the design of Medina Courtyard Addition and the Brand Solutions Office. David consults, both officially and unofficially, on almost every project we do. And on a personal note, David officiated at my wedding in 2002.

audio visual and acoustical engineering

MBF Audio/Visual

John Hardwick

Lake Stevens, WA

As a young architect and musician in New York City I spent a fair amount of time inside recording studios, so I have a passing familiarity with what makes rooms for listening and viewing work well, but if your project involves unusually complex acoustic requirements, I will call John. On our Multigenerational Passivhaus project for example he modeled the acoustic characteristics of the double height Great Hall, and recommended materials that would allow conversations to be comfortably heard while it was raining. Designing a sophisticated media room or rehearsal studio would also fall within his purview.