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Case Study: Carroll Gardens Passive House

May 5th, 2016  |  Published in Featured Projects

“What makes this project outstanding? Curve, wood, detail, light, detail, light… everything is related to everything else and everything circles back again and again.”

        ~Louis Mackall, Architect


This 5-story 1860’s Brooklyn townhouse features Zola’s triple-glazed Thermo Clad windows and doors in FCS-certified pine. An expansive, three-panel lift slide door spans nearly the entire width of the house, illuminating the whole floor. The rear facade is southern-facing, and the spacious dining room provides an ideal location for placement of this large opening.

Cost & Performance Considerations

The renovation of this home was not initially envisioned as a passive house retrofit. Homeowners Laura Mackall and Robert Manley explored the passive house option on a whim and determined during the bidding process that there was a relatively small cost difference associated with a passive house renovation. With these numbers in hand, the decision to go for passive house certification was logical.

DB-PH-9bFinding high performance windows that were large and quality-crafted was an important aspect of combining the passive house standard with the original intent of a top-notch design and tasteful renovation of the historic home.

Zola’s Thermo Clad windows and door line fit the bill. The home is extremely comfortable and energy-efficient. According to Laura Mackall, they did not turn the heat on all winter, and the inside temperatures stayed at around 70 degrees inspite of record-low temperatures in New York City this past winter. Architect Louis Mackall was impressed with level of insulation afforded by Zola windows and doors.

Louis Mackall: “Zola did a great job on Laura & Robert’s windows and doors.  They are very well made, and were exactly as specified for both dimension and function.  Their performance is a key reason that the house required no heating last winter (and that was a cold one!). I was very satisfied with the windows and doors. They are very efficient.”

Design Challenge: Faithfully Renovating the Brooklyn Brownstone 

Renovating a Brooklyn brownstone requires meticulous attention to the requirements of Brooklyn’s historic preservation commission. This project was even more challenging given that it also had to meet the passive house standard. Yale-trained architect Louis Mackall, Laura’s father, took on the design. Noting that passive house design requires thick insulating walls, Luis sought to avoid the “tunnel” effect common in window detailing. The interior window trims are angled, bringing  additional light and a feeling of openness to the rooms.

“It was primarily the window surround, or casing, which changed the room.  To put this another way, it was – yet again – the relationship of things which mattered, more than the things themselves.  Being a passive house, the exterior walls are very thick – the inner wall is quite far from the outer wall, with a window in between.  How, then, should this menage á trois (outer wall, window, inner wall) be married? Normally, it’s a simple casing – in this case a very deep casing. But in practice this puts the window down at the far end of a tunnel – orphaned out in Wisconsin somewhere with no one to talk to.”

DB-PH-30Zola Windows worked closely with Louis Mackall and contractor Build with Prospect, Inc. of Brooklyn, NY, to develop the design solution: a deep chamfer, flare, or battering so that the window sets within a frame. The angled trim design also provided the opportunity for adding traditional custom detailing and lighting. LED strips are integrated into the sills which provides a unique effect.

“Everyone is happy: the room because it has more light, the window because it is made bigger and the walls because they don’t pinch at their best friend the window. In our case, we then paneled that flared frame to make sure everyone knew we loved it even more than they did. And the panelling angled as it walked up, over, and around.”

This project was inspired by and focused on a need to make the most of the space at each floor. It was a complete gut renovation to an existing five-floor brick row house.   

Partnership and Flexibility. Louis Mackall asked Zola for a specific dado addition to the window jamb detail to allow a clean connection to the chamfered window trim. Mackall was impressed by Zola’s flexibility – the spec was was executed perfectly and greatly simplified the joint between Zola’s frames and the trim. The assemblies were then installed as a one piece frame, lead edges slipping into the dado for a perfect joint. 


About the architect. Louis Mackall (http://www.louismackall.com) has been practicing architecture since he graduated from Yale in 1968.  He also founded Breakfast Woodworks, a high end and technically advanced cabinetmaking facility. He is part of the renovation movement that is transforming the brownstones and old architecture of Brooklyn and other parts of New York into modern masterpieces. 

Build with Prospect, Inc., is a sustainable design-build worker cooperativbuild with prospecte devoted to creating low energy homes and buildings.  Prospect Architecture is the design portion of the firm located in Brooklyn, NY. The lead Architect is Jeremy ShannonBuild with Prospect, Inc. is committed to designing, constructing, and retrofitting homes with a focus on sustainable and ecologically sound principles.  These principles help Building with Prospects, Inc. provide clients with a healthier more comfortable living space while reducing yearly energy costs and improving the environment.