In spite of high-profile projects like the U.S. embassy now under construction in London, Philadelphia-based architecture firm KieranTimberlake still sometimes accepts commissions for challenging single-family houses. “They are an opportunity to try out things that would be tougher on a larger project,” says design partner Stephen Kieran.

A key example is the Loblolly House, a weekend home for Kieran's family on Taylor Island in Maryland, where he explored how far the concept of off-site fabrication could be pushed. But with the firm's first completed house since Loblolly—a year-round residence for a mutual fund manager and his wife who works in film production—the focus was the effect of the changing seasons and different weather and atmospheric conditions on the architecture. “Time was a big design element for us,” says Kieran of the latest house built on a wooded, 33-acre site in Pound Ridge, New York—a bucolic town about 50 miles north of Midtown Manhattan.

Here the primary medium for architectural exploration was the building skin—a rainscreen composed of metal panels with a variety of finishes that reflect light and the surroundings in different ways. But before designing the house and its unusual envelope, the architects had to first identify the best place to build within their client's property, a process that was far from straightforward. Although the parcel was large, it was strewn with boulders and interlaced with wetlands. It was also steeply inclined, rising about 100 feet from the road to the ridge—the geologic feature that the name Pound Ridge refers to.

Within this difficult terrain, the architects were drawn to a pair of “rooms” defined by rock outcroppings near the site's highest point. The two small, level areas were positioned one below the other and separated by a narrow ravine. The spot, according to Kieran, provided the opportunity to create a house that “sits lightly on the ridge but is grounded.”

Without any blasting, KieranTimberlake was able build a dwelling of more than 5,000 square feet by inserting a rectangular volume into each plateau. They are clad primarily with the metal panels, but also in bluestone masonry, which has a coloring sympathetic to the boulders on the site. A two-story structure, comprising a double-height entry stair hall, the garage, and bedrooms, sits within the lower rock formation, while the upper one holds a one-story living and dining wing. The stair hall serves as the linchpin between the two elements, which are connected by an approximately 17-foot-long glass-enclosed bridge.

The main, 12-foot-tall living space features white oak ceilings and floors and full-height windows carefully positioned to provide dramatic views of the site's distinctive topography. Kieran explains that the strategy for placement of these apertures was much the same as the approach the owners would later use for hanging their art collection, which includes works by Giovanni Battista Piranesi, M.C. Escher, and Frank Stella. “We were very curatorial about it,” says Kieran. The architects were just as deliberate with the placement of skylights above the bedroom wing's hallway. The slot-like openings create a rhythm of direct and reflected sunlight that animates the long, narrow space.

These interior elements make for an elegant and very livable house. But the project's standout feature is its exterior skin. The different facade materials—brushed and polished stainless steel (both over an aluminum honeycomb core), lead-coated copper, and the glass of the windows—produce a varied surface that simultaneously reflects the surroundings and transforms the building envelope into an ever-changing abstract pattern. The cladding performs almost as camouflage, especially at the corners, where the use of the mirrorlike stainless-steel panels makes the building's edges practically disappear.

The overall arrangement of the cladding panels, which are of varying lengths, widths, and depths, seems random. However, the elevations were the product of intense study, according to Jason Smith, partner in charge of the project. The goal was to waste as little of the stainless and copper sheet material as possible and minimize the number of the highly polished panels (which were the most expensive), while providing richness and diversity.

All this attention to the skin produced more than just a stunning aesthetic effect. The cladding is part of a thermally robust and nearly airtight envelope system that includes structural insulated panels (SIPs). The house, which was designed with Passive House strategies in mind, also incorporates radiant heating, a geothermal system, and an energy-recovery ventilator. Kieran likes to compare the Pound Ridge project to Philip Johnson's Glass House, completed in 1949 in nearby New Canaan, Connecticut. Johnson's house is visually open to its environs, since it has no interior partitions and is entirely enclosed, on all four sides, in floor-to-ceiling single-pane glass. In contrast, the triple-glazed windows on the KieranTimberlake house make up only 13 percent of the building enclosure. Like the midcentury project, the Pound Ridge house is an example of a “dwelling within nature,” says Kieran, but one without “the same energy consequences.”

Back to Record Houses 2015


Formal name of building:
Pound Ridge House

Pound Ridge, NY

Completion Date:
September, 2014

Gross square footage:

Michael & Olga Kagan

841 North American Street
Philadelphia, PA 19123
V: +1.215.922.6600
F: +1.215.922.4680

Personnel in architect's firm who should receive special credit:
Stephen Kieran, FAIA ' Design Partner
Jason E. Smith, AIA ' Partner in Charge
Jon McCandlish, AIA ' Project Architect
Trevor Horst, AIA ' Architect

Structural Engineer: CVM
Landscape Architect: Reed Hilderbrand
Civil Engineer/Site Planning: Kellard Sessions
Lighting Design: Filament 33

General contractor:
Prutting & Company

Peter Aaron/Esto




5,250 square feet

Completion date:

September 2014



Structural system
Lower level: Cast in place concrete, steel
Upper level: Structural insulated wall and roof panels (SIPs)

Exterior cladding
Masonry: Pennsylvania bluestone
Metal flashing and paneling: Lead coated copper
Rainscreen: Lamcel (stainless steel on aluminum honeycomb)
Wood soffits: Sapele Mahogany, White Oak

Membrane roofing: Sarnafil
Metal roofing and trim: Lead coated copper

Exterior windows and glazed entrances: Duratherm (triple-glazed IGU w/ double coating)

Entrances: Duratherm

Interior finishes
Entry level walls: Aggregate-blasted concrete
Entry level floor and exterior terraces: Pennsylvania bluestone
Stair and upper level flooring: White oak
Wall paneling: Black walnut
Stair rail: Burnished bronze


Lighting controls & shades
Controls & shades: Lutron

Other unique products that contribute to sustainability:
Structural insulated wall and roof panels (SIPs)
Geothermal wells
Dual energy recovery ventilators
In-floor hydronic heating