Among The Houseboats -- A New Home Takes A Few Cues From Its Portage Bay Neighbors

IT WAS A SITUATION RIPE for sibling rivalry - a brother and sister building new houses side-by-side with different architects, different designs and different aspirations.

Bill Henderson and his sister, Dr. Anna Chavelle, inherited their childhood home on Portage Bay and decided to build two new homes in its place. For decades the family's old green house had perched at the shoreline just above a sprawl of houseboat docks, prominently visible due west through the Montlake Cut and used as a navigational landmark by boaters.

"We've always loved this place," Bill Henderson said, "so after 40 years we decided to come home."

They hired Olson/Sundberg Architects of Seattle to untangle the property's jumbled platting and divide it into two buildable lots.

By the time Henderson and his wife, Diana, were ready to move forward with their house, architect Jim Olson of Olson/Sundberg had already finished a design for his sister. The Hendersons knew they wanted something different - not look-alike houses - and found it with another Olson/Sundberg architect, Tom Kundig.

For Kundig, the existing texture of the neighborhood, the visual effect of the houseboats and the pleasure the Hendersons took in looking at them were paramount in shaping the design.

The biggest challenge was trying to nestle a good-sized new home comfortably among the houseboats. To do this Kundig took a cue directly from them. "Part of the charm of the houseboats comes from the way they're built over time - if someone needs a kitchen or a second level, another piece is just added," he said.

He broke the mass of the 2,200-square-foot house down into three distinct pieces. A long, low bar fronting the street contains the kitchen, bathrooms and laundry. Along the water is the main living space, wrapped in glass and covered by a dramatic roof that angles out toward the view. Playing against these horizontals is a tower with a reading loft above the master bedroom.

Initial plans did not include a basement, but that changed when soil conditions proved better than expected. Instead of using concrete columns to support the house, a sophisticated foundation-wall system was built. It did not cost much more to finish the enclosed lower space for a guest bedroom, office and family room. The site's slope allows large windows and even a small deck off the basement along the water.

From the street, the house presents a private, almost guarded face. A lightweight metal handrail leads up a few steps to a wood deck recalling the boat docks below. Only the entry door relieves this no-nonsense facade.

At first glance it looks more like a working part of the waterfront than a home, but a few subtle details give tantalizing hints of things to come, such as a sleek steel canopy protecting the front door.

Visitors catch their first glimpse of the waterfront through a glass panel beside the front door.

Inside, the house resembles a loft with one large open space. This suits the empty-nest lifestyle of the Hendersons. The kitchen, living room and master bedroom are all on the first floor. "We plan to retire here so it is important that we are able to live on one level," Henderson said.

A few pieces of built-in furniture define separate spaces. A free-standing bookshelf provides privacy for the bedroom while a wood-and-glass cabinet partially screens the kitchen. "It's just enough so that the house feels open but not like a warehouse," Diana Henderson said.

Suspended on a platform above the master bedroom is a cozy reading nook with a large window overlooking the houseboats. "At first I didn't understand Bill's need for a crow's-nest," she said, "but now I see why he wanted to be up as high as possible."

For Kundig, interpreting difficult-to-articulate dreams is the true aim of architecture. The son of an architect, Kundig was raised in Spokane, where he worked in sculptor Harold Blazs' studio. "Harold taught me not to be afraid of art," says Kundig.

He sees architecture as an applied art that blends aesthetics with the needs and personality of the client.

One thing the Hendersons did not want was a fireplace.

"We'd rather sit and look out at the houseboats," said Diana. The south and east walls of the living room are floor-to-ceiling windows, allowing mesmerizing water views. Artfully placed window mullions create a Mondrian-like composition that frames the view and creates a sense of enclosure without blocking sightlines.

There is so much glass that the design almost exceeded building-code limits. To bring it within energy-efficiency standards, an insulated metal panel replaces glass in one part of the mullion grid. The solid rectangle provides a dramatic foil for all the glass and, Diana adds, is "a great spot to hang a painting."

Clearly visible outside the wall of windows is a row of steel columns supporting a large steel beam overhead. Exposing the structure that holds up the roof adds a layer of detail and depth to the house's waterfront facade. Kundig played up the home's structure in other places, too. On the south side, beams that carry the weight of the main floor extend out to intensify the sensation that the first floor is floating.

The general contractor, Dave Boone, was so proud of this project that he welded his signature onto one of the metal plates that cover the beam ends.

While the house reflects the Hendersons' appreciation for modern design, it also ingeniously makes connections to their past. Before the old house on the property was torn down, they salvaged artifacts from it to incorporate into the new home. A leaded-glass window from the old front door is now part of built-in cabinets in the living room. An old carved-wood bannister has new life as the railing down to the lower floor.

The home's furnishings are a similar mix of the old and new. The large breakfront in the dining room is a cherished piece from a beloved aunt. Interior designer Mary Siebert balanced family heirlooms with new custom pieces of furniture. She also chose the light sage color for the walls.

At first Diana was wary of painting the exterior wood siding yellow but now loves the warm wheat color. "This past gray winter convinced me that it was the right choice," she laughed. All of the house's exterior materials - the metal roof, aluminum windows and stucco base - were chosen for their durability. Next door, Bill's sister's house shares some of the same materials but is painted a soft salmon color.

While there is a definite family resemblance, each house shines without fighting the other. Framed by the Montlake Bridge, they gracefully inherit the role of the old family home as a local landmark.

Sheri Olson is contributing editor to Architectural Record. She is not related to Olson/Sundberg. Benjamin Benschneider is a Seattle Times staff photographer.