Project Spotlight: Brooklyn Retrofit Window Install
Bringing light into an early 1900s home
Recently, 475 did an on-site installation support for Duncan Architect’s project in Ditmas Park, Brooklyn. Duncan himself purchased the 1910 home which is located in the neighborhoods’ Historic Landmarked district and is now being retrofitted to meet PHI’s EnerPHit certification. The project team selected Bewiso VICTORIA simulated double-hung windows and doors. They are the sole PHI certified solution that have received Landmark approval in by New York City’s Landmarks Preservation Commission. Their superior Class A Passive House performance not only to ensures compliance with strict component certification criteria, it also provides superior interior comfort with even temperatures, no condensation, and quiet interiors thanks to their optimized frames and airtightness.
First Things First - Wall WRB
When we arrived the contractor had prepared the rough opening at the porch window in this woodframe building. The diagonal sheathing (Smart Enclosure approved!) will be air sealed with SOLITEX MENTO 1000 on the walls as the primary air barrier below a layer of exterior mineral wool - a vapor open assembly. The project will use INTELLO X on the roof above the 1x sheathing, below the roof’s mineral wool layer.
Rough Opening - Plywood Buck
Collaborating on this install was the (contractor name), Darren Macri (supporting the window installation), Greg Duncan, and 475’s Jeremy Latriano & Floris Keverling Buisman. Together we came up with the most practical solution to integrate the Bewiso windows into the SOLITEX MENTO 1000 WRB, as well as insulation and air sealing with Pro Clima tapes around the frame. Again, to insure the best performance of these certified units and to allow vapor to dry inward/or outwards depending on seasons.
MENTO 1000 was stapled into the rough opening, cut at the bottom of the sill, and folded into the sides. All exposed staples on the face of the WRB will be taped with TESCON VANA. Then a layer of 8” wide EXTOSEAL ENCORS was applied to the plywood window sill that was installed in the rough opening and matched to the depth of the exterior mineral wool. EXTOSEAL ENCORS is a must-have for durable protection of the window sill. It’s a high performance, waterproof flashing tape with acrylic modified butyl adhesive that works down to 15F (cold weather compliant) and forms itself to uneven substrates and self seals around fasteners.
Next the VICTORIA’s operable lower sash was removed from the frame. Normally one would then shim and screw the frame to the structure directly, but in this case Darren and the contractor preferred to use straps. Darren showed us all some tricks of the trade with the straps he provided.
In the following step CONTEGA SOLIDO EXO was used to tape the membrane to the side of the window frame on the exterior. For membrane application, a layer of MENTO 1000 was applied around the perimeter of the window rough opening. Typically we would advise wrapping the whole building before cutting out openings for each window (see flange window install guide on the product page), but for the purposes of this demonstration we hung the MENTO 1000 solely at the perimeter of the window. The overlaps of the Pro Clima WRB are waterproofed and airsealed with TESCON VANA, which also protects this connection with 100 year age-tested SOLID acrylic adhesion at these critical junctions. This further assures that the shiplapped membrane will protect his Passive House building and upgrades this landmark to 21st century performance, while the Bewiso windows and custom-built, triple-pane, LPC-approved door make the exterior match the 1910 facade (U-door of 0.14 btu/hr*sf*F - 0.77W/m2K).
The installed gaps between the rough opening and frame will be insulated with fiberous insulation - and air sealed with vapor retarding CONTEGA SOLIDO SL - which finishes the thermal-bridge-free insulation of the frame. (Watch our previous video demonstrating the interior air sealing of a Bewiso window on another Brooklyn historic home). We made sure to note to the contractor to complete seal the installation straps on the interior with this tape - a crucial step to avoid condensation next to the frame.
The VICTORIA window used here is Class A as certified by the Passive House Institute. Bewiso windows are manufactured in Austria by expert carpenters. Their narrow frames match the original sight lines of traditional double hung windows, while performance specs simultaneously exceed Passive House requirements for insulation, comfort, and efficiency. Most importantly for this project, these windows approved for use in historic districts by the NYC Landmark Preservation Commission. This approval is a necessity for this Passive House project, because of the project’s location in the Ditmas Park Historic District, an almost un-New York neighborhood with free standing colonial revival wood framed houses.
Bewiso’s obsession with performance combines the best practices of traditional craftsmanship, innovative design, and state-of-the-art technology, resulting in beautiful, high-performance all-wood windows that are a great match for 475 Smart Enclosure philosophy for historic buildings.