The Green Tree House
When architect David Sellers received an assignment to
build a home in Vermont's Green Mountains on a sharply
sloping, uncleared woodland site, he didn't hesitate to
take on the difficult project. In fact, he thought of it as
an exciting chance to flesh out his ideas for reducing both
the eyesore factor and the environmental impact of building
in a relatively unspoiled setting. It didn't hurt that the
client offered what every architect dreams of — a
nearly unlimited timeline and a great deal of budgetary and
Sellers already had proved his mettle: Named as one of the
world's 100 foremost architects by Architectural Digest in
1992, he had achieved recognition for his emphasis on
designing with nature as well as his work with pedestrian
and human-scale settlement patterns.
The prospective homeowner did give Sellers a few important
guiding principles: He asked that the home reflect the
Japanese architectural traditions he'd come to love through
visits to his daughter-in-law's homeland — simple,
natural materials and a connection to the surrounding
environment — and he wanted trees to be in the
forefront of the design.
A Discrete Footprint
Sellers began to plot a scheme for a structure that would
seem to grow right out of the hillside. "We tried to leave
the immediate surroundings wild. There's no lawn or garden,
just a few native plants for minimal landscaping," he says.
"An inch away from the house is wilderness."
Sellers carefully considered all of the treasures that
clearing the existing site would offer, from huge stone
slabs to stately, solid trees. "It's like a game of rock,
paper, scissors," he says. "You look at the choices
available to you, all of which might work, and consider
factors like aesthetics and embodied energy. Perhaps the
first choice has low embodied energy and is essentially
free because it's found on site. The second choice might be
economical as well because it's mass-produced, but it
involves a whole lot of embodied energy because of
manufacture and transportation. Then you have to think
about what other materials you'll use to go along with it.
For example, if you put in milled 2-by-4s, you have to use
a lot of other materials to cover them up and support them,
and that involves more embodied energy."
After local stone and salvaged trees were selected as the
major building materials, Sellers created a design that
relied on unsawn timber as the structure's vertical
supports. Construction began in 1996, but the house wasn't
completed until two years later.
Rick Moore, the contractor, had to throw out all
conventional timetables and procedures, and give in to the
demands of the site. "The land was so hard to work on," he
says. "We had to start at one end and work to the other,
piece by piece, in a sort of backwards fashion. All the
retaining walls and landscaping were done before we started
on the house. The framework of the tree supports was put in
place first, and everything was cut with chain saws, so it
was slow work. We did the framing through the winter."
Sellers' approach to the project was collaborative and
organic in nature, to say the least, Moore recalls. "There
was never any true architectural drawing, just sketches,"
he says. "They gave us a pretty good idea, but all of the
detailing was a surprise. Only the foundation had true
blueprints. And Sellers wasn't working very far ahead of
us. We used a clay model as our guide — and we had to
resurrect that from the architect's dumpster."
Looking at the holistic beauty of the finished project,
dubbed the "Tree House" because of the extensive use of
unsawn timber, one might find this story a bit hard to
believe. How could a house that seems so unusually grounded
in its place possibly have been created with conventional
The roofline echoes the surrounding ridges and is designed
for snow to pile on its uphill, near-to-the-ground side so
the house blends in with the winter environment. "It's
designed so that, when the roof is covered with snow in the
winter, you can't even see the house from that side,"
Because the house follows the site's natural undulations,
it was necessary to place the entrance at one end, with the
main hallway along the contour line. This means that all of
the public spaces — living room, dining room and eat-in
kitchen — are on the downhill side with the view. The
house snuggles up against the hill and opens up
dramatically to the outside, taking full advantage of
The concept of using indigenous materials for the Tree
House was a top-down decision, starting with native Vermont
slate for the roof. "Then we realized we'd have big rocks
pulled from the site for the foundation, so we started
refining it even more — using peeled logs from the site
for the interior structure."
The house really shines in these interior details, which
reflect Sellers' commitment to bringing outside materials
indoors and remaining true to the natural beauty of the
For an elegant design solution, Sellers says, "Don't use
rocks if you don't have rocks on your site. Use what meets
the main criteria for value, which is based on perceived
appropriateness for the site." The happy result of such a
decision is that it leads you naturally to support the
local economy and craftspeople, who are adept at working
with native materials.
About one-third of the Tree House's vertical supports are
trees from the property. Because they are unsawn, their
inherent warmth, sound-absorption quality and strength are
preserved. None of the wood is stained, and some trees even
retain their bark.
"The logic of using a tree you have to cut down to clear
the site, instead of a milled 2-by-4 from a tree cut down
thousands of miles away, is that it adds flavor and
sculptural quality, and a connection to the local
environment that's impossible to get any other way,"
The beauty of the majestic trees is deceptively simple. "To
remove the bark on some of the pillars, we had to hand peel
them and then clean them up with mallets," Moore says.
"They are all sealed with Verathane, a water-based
urethane. We put hot paraffin into the tree joints as
needed to slow drying and prevent splitting. But the trees
are shrinking a little bit, as we expected."
Sellers wanted the tree skeleton of the building to be
apparent, so that the lines could be visually traced
throughout the house. The big trees go from the upper
floors all the way through to the basement, making the
structure clear and understandable. "The elegance then
comes from simplicity, rather than a lot of elaborate,
decorative elements," he says. "The house is designed to
unfold as an experience. Upon entering, you walk down a
long hall through the 'muscles' of the trees lined up along
the hallway, with the main spaces opening up to your right
and the windows framed by big trees."
For many people, the choice of local building materials is
as much about their wallet as it is about aesthetics. In
the Tree House, much of the flooring, trim and door
material is beechwood because Vermont experienced a beech
blight in the late 1990s. The team salvaged some of those
dying trees and had them milled and dried. The beech
blended right in with the other materials. "Favoring local
timber sources over the more popular Western timber species
is akin to the growing popularity of microbreweries,"
Sellers says. "People want that local flavor."
Sellers experienced other similar good fortune. Looking for
trim to match the slate roof, he called several salvage
yards until he finally hit the jackpot. One had just
demolished an old school and had 50 old slate blackboards.
"I said, 'We'll take all of them!"' he says. To turn this
amazing find into workable trim, Sellers turned to the same
local expert — an experienced slate installer hailing
from a long line of slate men — who had applied the
The sauna building, with walls built entirely of these
recycled slate blackboards, was added as the final touch.
It has no foundation; to avoid disturbing the topsoil, the
crew drilled holes and inserted stainless steel pipes into
the bedrock for supports. "The building sits like a spider,
with pins locking it into the ground," Sellers says. "Water
can run undiverted under it."
Troy Osborne, a member of Sellers' firm, likens the
collaborative effort of architect, contractor and homeowner
to the process of making a film or performing in a jazz
group. "It's taking a unique concept, adding particular
players and seeing what comes of it," he says.
As the head of that ensemble, Sellers is pleased that
everything came together so pleasantly. "As an architect, I
can only argue my case for a short time — while I'm
working on the project. So in the end, the building must be
a self-evident statement about materials and design working
together that lasts after I walk away."
Reprinted from Natural Home magazine.
Building Tips From the Architect
David Sellers offers these tips for any building or
remodeling project, including those on a tight budget:
Be a cheapskate . "Find local materials
that are free, and use them as you find them. This will
connect the house to the local landscape and save you
money. For example, the local beechwood used for flooring
in the Tree House, even after milling and drying, was still
cheaper than buying something like precut maple."
Splurge on the details . "Spend a decent
portion of your budget on a few special, stunning
details — perhaps the kitchen cabinets or the
hand railings. Employ skilled local craftspeople for those
Recruit local talent . Use your project's
exceptional elements to attract the attention of other
local talent. Through the work of many hands, it's possible
to turn your project into a community showpiece. "If you
make your building project something unique and special,
people will come out of the woodwork to give you a break
and be part of it, especially if it might add to their
portfolio of work and possible exposure."