Architect Joe Eisner’s goal was to turn this Westchester, N.Y., basement into valuable floor area that integrated the space into the rest of the home. The project greatly increased the home’s living area without the addition of new square footage. Moving from dark and damp to a light-filled hub — with a play area, exercise room, home office, bar, storage, and guest bedroom — took determination and demolition. The design became mostly about subtraction: to develop a way to draw light from an upper floor as well as from the backyard.
Eisner wanted a grand entry to “make the basement meaningful to the home.” To achieve a floating look, the structural staircase connections are buried inside the walls and under the floor. At the top of the stairs, the center steel I-beam (clad in bamboo) is anchored to a large steel plate bolted to a steel beam buried inside the balcony. At the bottom of the stairs, the I-beam is connected to another steel plate bolted to an existing concrete slab that has been tiled over. “You see almost no connection or structure attached to anything,” says general contractor Michael Amnon, owner of ID Renovation Solution, in New York City.
The stairs seem light and open, yet they meet code. Bamboo treads rest on steel plates that lip up in back to reduce the openness of the rise to less than 4 inches, as per code. Round steel tubing is spaced every 3 inches under the wood-capped steel banister.
The structure’s steel portions took three weeks to fabricate at Interior Designs Metal, in Brooklyn. Signature by Al, in Paterson, N.J., fabricated the stairs. Three people installed the stairwell on-site; one person from Norwegian Wood Floors in New York City installed and refinished the wood treads. “It was an easy and clean installation,” Amnon says.
Add an Atrium
To increase light and better integrate the basement into the home, the design called for the demolition of a portion of an upstairs play area to help create a two-and-a-half story atrium. “By taking away that space we created vertical circulation between the basement and upstairs,” Eisner says. “We wanted these two floors to have a direct dialogue with one another.”
On one side, the drywall is clad in bamboo panels. Concealed wood framing with steel reinforcement provides the support for the balcony cantilever.
The adjacent glass and aluminum grid wall — using a storefront glazing system — was Amnon’s biggest challenge. “About 23 feet needed to be shored up so the glass would not shake or move,” he says.
The aluminum grid was delivered in pieces and put together on site. The metal strips were anchored to the side walls to support the weight of the glass and anchored top and bottom to a metal strip bolted to the ceiling and floor. The glass was then inserted into the grid.
Lighter-weight translucent tempered glass provides privacy for the basement office as well as meets code for low-height glass in the main-floor den.