An Aggressive Passive Push for a Brooklyn Brownstone

This article is part of our Design special section about making the environment a creative partner in the design of beautiful homes.

When Hope Reeves and Martin Walker bought an 1899 brownstone in Carroll Gardens, Brooklyn, five years ago, they knew it was going to require a lot of work to meet their ambitions for a smartly functional and stylish home to share with their three sons.

For decades the building had been owned by the same extended family, whose members created separate apartments on its four floors of living space. “Every floor had its own kitchen and bathroom and velvet wallpaper and stuff that had been here for 60 years,” said Mr. Walker, 57, a former information systems specialist and founder of the online brain fitness company MindSparke, who records and performs rock music under the name Art Schop.

Likewise, badly deteriorated plumbing and electrical systems needed wholesale replacing.

On the bright side, it was a generous size at 25 feet wide and had garden areas in the front and back. It was also, atypically, attached on one side only, meaning there were three exposures for maximizing light.

Though much of the interior architectural details had been stripped away, intricate crown moldings in the parlor remained, as well as elegant wainscot along the staircase, and wide-plank pine floors that in many rooms had been covered up with carpeting or linoleum.

The couple, who paid $4.75 million for the property, according to public records, enlisted Baxt Ingui Architects for the renovations, with the goal of preserving as much historical charm as possible while implementing energy-responsible upgrades.

Known for designing with Passive House principles, which are aimed at making residences better insulated, airtight and more energy-efficient, Baxt Ingui embraced the historical and environmental considerations with equal vigor.

On the exterior, the architects added a period-style cornice to the street-facing facade and used archival photos as reference to restore lost Italianate details around the windows and front door. Behind the house, a free-standing two-car garage that occupied much of the back garden was reduced to about half of its size and converted to a games pavilion, with room for an outdoor seating area beside it.

Inside, the renovation strategy essentially began at the top, with the attic. At the time, said Ms. Reeves, 51, a freelance writer (who has contributed to The New York Times), the attic was a “dark, musty little space with tiny windows” reached by “a rickety, old iron ladder.”

That inhospitable domain is now a sun-splashed home office with expanses of nearly floor-to-ceiling glass offering panoramic views of Lower Manhattan.

According to Michael Ingui, a partner in the firm, the transformation required a loss of habitable space elsewhere because the residence, roughly 5,000 square feet, not including the attic and basement, was at the maximum allowed by zoning regulations. The architects’ solution was to remove a large section of the parlor level at the back of the house and create a double-height kitchen and dining area whose floor is positioned roughly midway between the parlor and garden levels.

Not only did the open, split-level configuration solve the square-footage issue but it effectively tied together all of the entertaining spaces. And by making the 15-foot-high rear wall of the kitchen and dining area almost entirely glass, while also adding two tall windows in the parlor, the architects ensured that natural light flowed freely through those areas. That included the garden-level den, a space that Mr. Walker noted had been “the darkest, dingiest room in the house” (not counting the previously unfinished cellar, which is now his airy music studio).

At the same time, exterior walls were insulated and sealed, and triple-pane windows were installed, eliminating drafts and insects and reducing noise and dust. “It’s kind of crazy,” Mr. Walker said. “You sweep the floor, you just get crumbs. There’s none of this New York black dust.”

The airtight walls are “vapor open,” Mr. Ingui said, “letting moisture out so the house can breathe.” Air is filtered and circulated through an energy recovery ventilator (E.R.V.) system, which keeps it fresh and clean, while also helping to regulate the internal temperature. The enhanced energy efficiency achieved by the Passive House strategies eliminates the need for a boiler or radiators, reduces the amount of ductwork and allows for smaller mechanical systems throughout.

It also made the decision to remove the parlor fireplace an easy one. “The reason most of our Passive House clients take the fireplace out, other than giving them more space, is simple,” Mr. Ingui said. “You’ll never use it, ever. It gets too hot.”

Mr. Martin confirmed that the family rarely turns on the heat, which like the air conditioning uses an electric-powered system of high-efficiency units known as mini-splits. The air conditioning gets more use, he said, but requires significantly less energy than a conventional central cooling system and doesn’t need to run as long.

Helping to offset some of the family’s electricity costs, a modest 5.25-kilowatt array of solar panels on the roof produces close to a quarter of the energy they consume. It could provide more, said Mr. Ingui, if city building codes are updated to allow batteries to be used with residential solar systems.

The decision to insert skylights into the attic office reduced the area available for solar panels, but the trade-off was that light now streams down through the stairwell — which the architects widened — enlivening the home’s previously dark core.

Custom plywood shelves and cabinets installed in the breakfast area and den — a contemporary contrast with the home’s Victorian-era decorative elements — were championed by Ms. Reeves, who spearheaded most of the furnishings. While not of the 1890s, her choice of vintage modern seating and lighting, mixed with select new pieces, conveyed a sense of historic layering.

Respecting the townhouse’s past was essential to the couple, who could have saved themselves time and money by doing more demolishing and replacing. The same goes, to a certain extent, for their decision to prioritize sustainable features, which Mr. Ingui estimated added four to six weeks to construction time and around five percent to the total cost.

That calculation, he noted, depended partly on the quality of the windows and the HVAC system — boiler, radiators, piping, in-floor heating, thermostats — that would have been installed instead.

Ms. Reeves said that “not doing passive, solar, low-flow water fixtures, et cetera, honestly didn’t seem like an option to us.” Regarding the added upfront costs, she said, “It just seemed like the price we would pay for the privilege of having this house.”

In a city with a lot of aging, inefficient structures, the townhouse shows how an older building can be preserved and upgraded for luxury and comfort, while also making it more environmentally responsible. “We breathed new life into it,” said Mr. Ingui. “The updates will last well over 100 years, through multiple generations.”