Whitney Sander, Sander Architects, Venice, Calif. (USA), began exploring prefabricated construction long before anyone really knew what it meant. Since then, Sander has developed design and construction techniques that have advanced prefabrication from a confusing concept into an architectural art form. Sander's designs use a prefabricated steel structure, an idea borrowed from the warehouse manufacturing industry, combined with traditional finishing methods that bring luxury home features, like soaring ceilings and unobstructed floor plans, into lower-budget markets.

Branded Hybrid House, Sander refers to the designs as "part pre-fab, all custom^TM." Prefabricated steel components become the main frame around which a home can be closely customised for the person and purpose that will inhabit it. Sander approaches projects with a desire to find a balance between poetry and pragmatics, encouraging forms to develop which satisfy basic needs while embracing the possibility of the poetic. In this way, a house for an orthopaedic surgeon becomes a covert study in anatomy--metaphorical skin and bones. An aerobic studio's interior takes on physical attributes of tension, compression, torsion and sinew. Likewise, the Residence for a Sculptor is a ‘vessel' whose proportions are based on a large-scale clay jar produced by the owner.

The upside exterior reveals steel structural "bones  

Sculptured Design Residence for a Sculpture sits on the edge of a steep hill overlooking the Valley of the Moon in Santa Rosa, Calif. Its design presents a series of tensions and unexpected experiences. First impressions allude to a horizontal arrangement with a broad view of the valley. Entry to the house is situated on the uphill side away from the view, and instead gives access to a vast vertical foyer that stretches to a 2.1m² ceiling. A winding stair case, a massive torqued steel sculpture that spans the foyer's height, and an artful use of light echo the owner's pottery that is displayed on staggered platforms. The expectations for an outward experience are surprised with an inward, vessel-like focus. A walk up the long flight of stairs and across an open-grid steel bridge brings you out of the closed vessel into a wide open great room with large windows overlooking the valley.

The owner-artist's own work can be seen throughout the house in handmade bathroom tiles, kitchen countertops and backsplash and design elements in the exterior. As well, the great room design provides a natural space for a gallery of his pottery work.

Inside the exposed steel structure suggest the appearance of a modern sculpture. Circular bolting system adds axial beauty

Steel bones provide structure and visual elements

The home's upside exterior reveals the steel structural "bones" that make its hillside perch and expansive interiors possible. This structural frame, made of rolled steel, is prefabricated offsite, transported to the location and assembled like an erector set. The steel frame is bolted together using a unique system. "Most steel frames are welded together using butt frames, but this structure places the beams face to face and is joined by an 8-bolt circular array," Sander explained. "Just tightening these bolts gives the house all its strength and shear resistance."

Inside the exposed steel structure suggest the appearance of a modern sculpture. Circular bolting system adds axial beauty

The steel beam structure plays an important role in the interior as well. Inside, the beams are exposed in the great room walls and ceiling, adding interest, texture and suggesting the appearance of modern sculpture. "The beams with its eight bolts in a circle have an axial beauty and are meant to be a part of the sculpture, while being entirely useful to the structure," Sander said.

The 420m² Residence for a Sculptor is just one example of how Hybrid House can be employed to build a custom space. Hybrid House can be scaled down to a low-cost first home or up to a 740m² resort home. The secret lies in the prefabricated steel construction system that provides efficiency and flexibility regardless of the home's size.

"There is no better material for building a house," Sander said. "You need to know the process of working with steel, and you need to understand its strengths and weaknesses. But once you have that knowledge base, the sky is the limit to what can be achieved."

The architect is currently working on another home for a music critic that wanted to push the envelope for green building but had a small budget to do it. Sander worked out a plan that fit the budget and the environmental considerations, and even included a large open floor space where the owner can stage chamber concerts. "The house uses a prefab building shell, made in inland California, which was delivered to the site and assembled. The entire shell cost about €16,000, including all structural frames, all secondary structures and the building skin and roof," Sander noted. The prefabricated structure allowed Sander to include upscale features like 3m² ceilings, concert hall-like living room space and the desired environmental upgrades while staying within the owner's small budget.

The upside exterior reveals steel structural "bones

Building that embraces "green"

Hybrid House's structure is made completely from steel recycled from vehicles, and it can be dismantled and recycled again at end of life. As well, offsite fabrication reduces construction site waste as well as energy use. Sander also strives for the least impact on the environment, from construction through every day use, and incorporates other green building practices. His projects include walls systems that use a sunflower board instead of traditional sheet rock and are insulated by shredded blue jean material. Grey water capture system, passive solar hot water heating, active electronic solar generation and other systems are considered to fit client needs. "The (construction) industry is undergoing an extraordinary change now with a complete paradigm shift towards green building. We are always looking for the best developments in environment-conscious building materials."

Learn more about Sander Architects at www.sander-architects.com/.

Key information

Number of storeys	2
Living area	420 m2
New-build home

Location of steel solutions

Structure (prefabricated)
Light steel sections
Roof