Greening the Gilded Age

Want to learn how to turn an age-old ruin into a green modern palace? Follow Polly Guth on her mission to make Stonlea, her sprawling Gilded Age estate in Dublin, a net-zero energy mansion, writes Steven Kurutz.

It was a gray and cloudy morning, and the fog was rolling across the grounds of Stonlea (pronounced stone-LEE), a sprawling Gilded Age estate here on a hill overlooking Dublin Lake, with a view, on most days, of Mount Monadnock. Polly Guth, the 87-year-old owner, was leading a visitor on a house tour that featured lots of the expected Gilded Age-y things.

 Old money, modern twistStonlea served as the Eastern summer house of prosperous tobacco growers from St. Louis, completed in 1891 by the Boston architecture firm Peabody & Stearns.

Guth, a philanthropist and a descendant of one of the founders of the pharmaceutical company Merck, was doing little to lighten the old-money mood. Only when she walked down a long hallway and stopped to look out a window did the tour take a modern-day turn. Through the fog, in a field ringed by forest, you could make out giant steel pedestals, 16 of them, each affixed with solar panels angled toward the sky.

“Everyone said, ‘Where are you going to put the panels?’ ” Guth recalled. “I wasn’t going to try to be discreet about them. I wanted people to know this house was heated by solar panels. I think they look great.” The panels were positioned to evoke an army of samurai advancing on the house, she said.

What’s in an old ruin?

Five years ago, at a time when many people her age were downsizing to one-bedroom condos, she bought this 12,000-square-foot colonial revival home on 30 acres and set about addressing, as she politely put it, the “deferred maintenance.” In fact, the place had never been properly winterised and was a bit of a wreck. Hugh Hardy, the architect Guth hired to restore the home, said the previous owner was able to live there year-round by shutting off every room but the kitchen, and stuffing blankets into crevices. “It was a little like some Russian play,” Hardy said. “The estate was falling apart, funds were being diminished.”

From old to gold

But more than just restore and bring Stonlea into the 21st century, Guth wanted to make it net-zero: a building that produces as much, or more, energy than it consumes. It’s the sort of eco stamp you expect for an Earthship built from rubber tires and soda cans in the New Mexico desert, not a rambling New England estate. For Guth, that was the point. “I did this so other people would follow this example,” she said.

Part historical preservation, part green building experiment, the home’s makeover was recently chronicled in “Stonlea: A Timeworn Gilded Age Survivor Transformed,” by Peter W Clement and Victoria Chave Clement (Bauhan Publishing). The book is filled with historical photos and a hammer-and-nail account of the renovation, which took two years, two architects (Hardy worked from New York, while Daniel Scully, a New Hampshire architect, supervised on site) and a team of engineers, experts and builders.

A home like white elephant!

What was Guth’s first impression of her new house? “Absolute horror,” she said.  There was much work to be done, starting with the floor plan. Stonlea remained awkwardly cut up, with separate entrances and zones for the owners and their servants, whose quarters were tiny, dark warrens. As Hardy put it, even today’s wealthy “no longer live in that formal, ritualistic way. To make it useful, you had to change that.”

Stonlea’s identity as a summer-only retreat also proved a problematic holdover from the past. The walls were haphazardly insulated, the foundation riddled with leaks that hardly mattered if you packed up the silver and returned to your main estate come September. Guth could have had insulation blown into the walls and jacked up her thermostat to cover the inevitable heat loss.

 But her desire for a net-zero house required a more rigorous approach. Stonlea’s outer shell was stripped down to the studs and the building was made airtight: foundation repaired, sills patched, chimneys repointed, new insulation installed, the roof recovered with more solid sheathing and wood shingles. The existing single-glazed windows were bi-glazed, and with the addition of an interior storm window, they essentially became triple-glazed to prevent air leakage, said Scully, the architect who supervised on site.

 Home or energy store? Both!Meanwhile, other tests were done to determine how much solar and geo-thermal energy Stonlea would use in a year. The solar field that was ultimately installed was a 50-kilowatt system, capable of generating 70 per cent of the home’s substantial yearly energy needs.

Peter Bonneau, the project’s construction manager, said Stonlea was at the time “the biggest private residential solar array in New Hampshire,” so big that conventional battery storage was impractical.

Energy is sent directly to the power company in times of surplus, and power is purchased as needed (in gray winter, for example).It may be more realistic for owners of large old houses to come up with a strategic energy master plan, and work toward a goal of net-zero over time. 

However, Stonlea is perhaps less a new energy-efficient model for old houses, as Guth intends, than a philosophical ideal manifested into reality through one woman’s will. 

She hopes those who hear about Stonlea will learn something, as well. “It shows that a big old house can remain relevant,” she said. “Even though it changes families and the times change.”