July 2011
BuilderNews Magazine
Feature: Project Profile
Sustainable in the Desert
Howling Winds, Scorching Sun? No Problem
Every new construction project starts with a few parameters: site constraints, budget, or a client’s special wishes. This project had a list.
The challenge: Design and build a low-cost, sustainable home in the Mojave Desert, where the sun beats down 350 days a year, the wind blows like a sandblaster, and the summer heat can top a blistering 115 degrees.
The solution: ISO shipping containers.
The project began in early 2009, when the client, Lion’s Gate movie executive Tim Palen, contacted architect Walter Scott Perry, founding principal of ecotechdesign in Los Angeles, CA. “The client wanted to build something in a remote location, for very little money, and in a short period of time,” Perry recalls of their initial meetings. Perry has worked with sustainable design and architecture since the 1970s and often takes a “kit-of-parts” approach to his designs, freely mixing conventional and innovative materials. “Shipping containers,” he says, “just seemed like the most cost effective and expedient way to do it.”
To arrive at this conclusion, Perry first worked through each of the project’s three major constraints: budget, time and the environment. The building site, a two-and-half-acre lot, sits on a small bluff outside Joshua Tree, CA, overlooking the low mesquite and chaparral brush lands of the Mojave high desert. It is hot and dry and difficult to access, making it a tough place to deliver materials and an even rougher place to work. This led Perry to first consider a standard prefabricated home, something often used in the region, which would go up quick and require the least amount of on-site labor. The only catch was the price. The client set a budget of $250,000, and as Perry notes, a high-quality prefab in southern California can run $250 to $350 a square foot. Not much home for the money, unless the price could be reduced. Perry’s initial estimate for the purchase, fabrication, and install of shipping containers was $100 a square foot.
The Mojave high-desert environment further lent itself to Perry’s shipping container design when he considered the long-term impacts the desert would have on the home. Shipping containers — manufactured, most recently, from core 10 steel and sealed with a two-part, marine-grade primer — are one of the most indestructible structures on the planet. The corrosive, salt-laden wind and persistent sun of the open ocean, for all its water, is remarkably similar to conditions in the desert. As Perry says, “If you framed this thing out of wood, the sun would just eat (it) up.” The obvious solution was steel, and shipping containers fit that bill.
Working then off the modern, industrial look of the shipping containers, Perry was able to move onto other elements of the design. One in particular is the client’s photo studio. “The owner wanted a box,” Perry recalls, a large, light-controlled box to be used for photo shoots. All factors considered, Perry was drawn to a Butler, pre-engineered steel building, with industrial ribbed metal siding. The building, a standard commercial unit, melded well with the aesthetics of the shipping containers, while also conforming to the project’s three major constraints. It was low-cost, durable, and could be assembled in a matter of days.
Another key element in the home’s design is the custom-built, sunshade, which forms the roof and southern façade of living area. Shade in the desert is a vital commodity, and Perry designed that commodity into the home. Between the living area to the west and the studio to the east, Perry left open a 400-square-foot “desert room,” with lush greenery and a paving stone and pebbled floor. The sunshade, constructed of repurposed industrial struts and perforated aluminum panels, forms the southern wall and roof of the desert room and extends out to shade the house. An eight inch gap separates the sunshade from the building’s exterior and, all told, reduces the home’s solar exposure by 50%. As an afterthought to the design, Perry might incorporate different panel opacities to achieve varying levels of shading. “On the roof, for example,” he says, “you might have 80% shading, (while) on the walls you’d have 50%, because you want to see through the walls.”
The builder on the project, Eric Engheben, owner of 44 West Construction in Topanga, CA, first met with the client at an LA home show, where 44 West had a renovated shipping container on display. 44 West began working with containers in 2006 and had since completed four shipping container projects, along with its high-end custom homes. The Tim Palen Studio at Shadow Mountain would be the company’s fifth and largest container project to date. “We like the opportunity to work with something different.” Engheben says. “It is more of a challenge.”
44 West works out of a 12,000-square-foot facility in Gardenia, CA, where it fabricates the containers into various modular units, fully finished and ready to install. To Perry, this was part of the appeal. “We do everything,” Engheben says. “The containers are laid out in the yard, and we do the cutting, the framing, plumbing, electric — everything. We then package them up, protect the windows, take out the sliding doors, and head-on down the road. All that is left to do is to secure the units to each other and to the foundation and tie the mechanicals together.”
Construction on the project began in early 2010, with 44 West purchasing six containers from the docks of Long Beach for $2,600 each, which it then fabricated into different units: three for the ground floor living space, two for the second floor bedroom and bath, and the last as a storage unit off the studio. The exteriors were then painted with a standard, low VOC exterior paint, white to reflect the sun, and custom Milgard windows were installed. To finish the interiors, 44 West uses steel studs encased in a three-part insulation system that creates a R26 wall, with two thermal barriers separating the interior from exterior wall. A layer of spray foam is affixed to the outside wall; the cavities are filled with Wool batts; and foam board sheathes the studs. Plywood is then installed and skim-coated for appearance. Plywood, Engheben explains, travels better than sheetrock.
Wanting to keep as much as possible of the container visible, Perry and the client chose to leave exposed the container’s original plywood floors, sanding and sealing the plywood with water-based polyurethane. Mahogany plywood, matching the container floors, was then used on the home’s circular staircase. The ceilings of the units were also left exposed and insulated from above with R40, slanted foam boards, Densdeck roof boards, a cool-roof TPO membrane, and, over the living quarters, the perforated sun shade.
To Engheben, delivery and setup of the containers was the most dramatic and satisfying part of the project, when in a matter of hours the building site was transformed from an open site of concrete stem walls and piers into a nearly fully finished home. “A lot of people who have come to watch the process say, ‘I could never have imagined that what you were building in that facility would end up like this,’” Engheben says. “When you build a two story home in a facility and everything is on one floor, the containers are four feet apart, and when you walk between them it gives you a cavernous feeling, confined. When these are put together and it opens up the space, people are amazed.”
In less than a year from the start of construction, the Tim Palen Studio at Shadow Mountain, a 2,300-square-foot, one bedroom, one and a half bath home, including a 1000-square-foot photography studio, was constructed for the finished price of $150 a square foot, nearly half the cost of a comparable prefab home.
“I always try to clarify affordable housing versus affordable architecture,” Engheben says. “What we provide is affordable architecture. The custom homes we build start a $300 a square foot and go up to as much as $1000. We can do these for $200 a square foot that gives you the same level of detail and quality that you’ll find in a custom home.”
Behind the numbers:
Project Name: The Tim Palen at Shadow Mountain
Photography by: Jack Parsons Photography
Architect: Ecotechdesign, Walter Scott Perry, AIA
Builder: 44 West Construction, Eric Engheben
Project location: The Mojave Desert, Joshua Tree, CA.
Project type: Custom Single Family Home
Project Design: Modern; Sustainable
Date started: May 2010
Date completed: February 2011
Construction methods: Fabricated shipping containers and a pre-fabricated steel engineered building
Number of containers used: Six
Container dimensions: 20 ft long x 8 ft wide, with 8’6” ceilings
Container size: 160 sq. ft.
Total House size: 2300 sq ft
Total living space: 900 square feet
Steel building/ studio dimensions: 36 ft x 24, with added shipping container
Studio size: 1000 sq. ft.
Outdoor, “Desert Living Room”: 400 sq. ft.
Number of Bedrooms: 1
Number of Baths: 1.5
Lot size: 2.5 acres
Climate: High Desert: Hot and Dry
Elevation: 2700 feet
Average annual temperatures:
Average yearly low temperature: 340F
Average yearly high temperature: 1000F
Yearly rainfall: 4.57 inches
Annual rain days: <10 days
Annual sunshine: 350 days
Project Specs:
Exterior construction: ISO Shipping Containers; steel studs; wood studs; Butler, pre-engineered building
Exterior siding: Existing container; corrugated metal siding
Interior sheathing: Plywood, with skim coat
Flooring:
Living Space: Existing container plywood flooring, sanded and sealed with water-based polyurethane
Stairs: Mahogany plywood
Studio: Polished concrete
Foundation:
Living Space: Stem walls and piers
Studio: Slab on grade
HVAC: Forced air, split-unit heat /cooling pump
Sustainable/ Green Amenities:
Double-plumbed grey water irrigation system
Rain water harvesting, with 3,000 gallon storage tank
R-Values:
Walls: R26 / California code: R19
Ceiling: R40 / California code: R30
Finished price, per square foot: $150