What could be better than renting a 200-year-old house as a weekend escape? Building a new glass-and-stone home and running an organic farm there.

After renting a 200-year-old farmhouse on 230 acres in Stanford, N.Y., for four years, Soo Kim and Carolina Gunnarsson couldn’t imagine any better place for a weekend escape from Manhattan.

“We loved it so much. It’s very secluded; the only neighbors were cows,” said Ms. Gunnarsson, 32, a founder of Fit Pregnancy Club, a prenatal fitness studio in SoHo. “It was always our dream that we would be able to buy

In the beginning, they had a few changes in mind. They wanted to clear some of the overgrown farmland, add a pool and build a modest addition to the house

For about a year, the architects worked on plans for an addition as the project expanded to include space for a larger family. , but they suspected more children would be in their future. Today.By the time they finished adding rooms to the proposed structure, it dwarfed the original building. “It became the addition that ate the house.

After a pause, they decided to start over and design an entirely new house slightly farther up the hill, leaving the farmhouse intact as a guesthouse.

For the new 4,600-square-foot house, the Slades conceived a home formed by two overlapping, perpendicular boxes. One box, which sits low on the hill beside a retaining wall, is clad in dry-stacked local stone and Cor-Ten steel shutters. It contains the private functions, including five bedrooms, a family room, a study and a mudroom (plus a playroom in the basement). The other box sits on top, with a living room, dining area and large open kitchen wrapped in floor-to-ceiling glass.