Stopping in at the Park Slope “Tighthouse”


Recently we checked in with architect (and Hot Seat interviewee!) Julie Torres Moskovitz on her firm’s Passive House project at 23 Park Place. For those confused about what a passive house is, she explains: “The Passive House standard focuses on 5 main strategies: 1. Insulate strategically; 2. Stop thermal bridges; 3. Achieve air tightness; 4. Install high-performing windows for thermal comfort; and 5. Reduce mechanical systems with heat recovery ventilation.” 23 Park Place, dubbed the “Tighthouse,” just met the air tightness requirement of a passive house, actually reaching a record “air tightness” level for any NYC passive house. (A certified passive house is 15 times tighter than current building norms.) Interior work on the project isn’t done yet, but Julie says: “We feel good about the air tightness result we just received because it implies that the existing building stock in urban settings can achieve high energy performance results with some investment and care.” Click through for pictures of the project.
Out From Under Scaffolding: 23 Park Place Passive House [Brownstoner]
Slope Passive House in the Works? [Brownstoner] GMAP

Skylight, “air tight” detail

Facade and drainage board

Window header detailing

Window tape and membrane

33 Comment

  • no-permits

    that’s not prospect heights, it’s park slope.

  • I know this has come up before, but I just can’t stand those single pane windows on an historic house. I realize that double hung windows are not as air-tight, but these windows are just awful. Couldn’t they at least use a dark bronze frame and a fake mullion to make the windows blend in a bit.

  • I too absolutely HATE with a passion single pane windows. They are ugly, ugly, ugly, and to me they look like they should be in an office building, not a home.

    So how much more air tite are they in comparasson to double hung, like seriously how much money are they going to save for you, how are they going to improve the quality of life in the home???

    Six over six bronze would be the better choice.

    I also agree with Joeinbushwick, they could have of least made them bronze with the grid in them.

  • And I disagree. I think they speak to the future rather than a fetishizing of the past.

  • I like the single-pane windows. I think they’re very attractive. I hope they paint the frame to match the color of the house, though.

  • no-permits

    what’s wrong with letting the house breathe a little? why does it need to be air tight?

  • Yes the point of a Passive House is to completely control air leakage, which is a major cause of heating/cooling requirements. PH’s quite often don’t even need heat turned on in 30deg weather. So you save a *lot* on energy costs.

    Now the tradeoff in needing mechanical ventilation 24/7. But many condos and new constructions have that anyway so it’s not that different. Personally I qould be leery of it because I like to open windows at will, but even that is not in conflict with PH.

    About windows, makes a big difference to have good (non doublehung) ones. I don’t see the hate for modern windows, I intend to change all my double-hungs to more efficient ones before landmarks catches up to my block. I may put in the false separators, though, because I think they look good, not because of some antiquated historicity.

    • Thanks cmu for a sensible post. Providing an air-tight seal for your building envelope minimizes heating/cooling fluctuations and the associated energy costs. It also has an additional benefit of keeping unwanted moisture leakage, which can be trapped inside causing molding problems and other particulates.

      And those complaining about the double hung windows, as cmu pointed out, you can easily can fake muntins to achieve the same architectural look.

      As a side note, I don’t quite understand why so many on this forum is so resistant and skeptical to change and/or technology. It must be the generational gap or ignorance. What’s so wrong about looking at changes which can potentially make your life better and as well as improving the environment?

      • Even if the single paned windows could have the fake grid inside them, I like double hung windows because i like the way they go up and down, I can open the window and raise the screen and stick my head out, or shake the rug out the window. I can open the top if need be as well and the best part is having the windows tile in so i can clean them.

        this is why i prefer double hung windows.

        if I couldn’t lift the screen to stick my head out the window, I would have a problem with that.

        also with swivel in windows how do you mount blinds, shades or curtains if the window swings in?

      • Even if the single paned windows could have the fake grid inside them, I like double hung windows because i like the way they go up and down, I can open the window and raise the screen and stick my head out, or shake the rug out the window. I can open the top if need be as well and the best part is having the windows tile in so i can clean them.

        this is why i prefer double hung windows.

        if I couldn’t lift the screen to stick my head out the window, I would have a problem with that.

        also with swivel in windows how do you mount blinds, shades or curtains if the window swings in?

        • i have tilt and turn windows that swing inwards and am currently looking for a window treatment solution. does anyone have suggestions? we love the windows by the way but we definitely need to figure out the best way to install blinds/roller shades.

          • Maybe the curtains would have to clear both sides of the windows to have them open and close properly.??

            I though they made those kinds of windows with blinds already in between the glass panes with a knob at the bottom to tilt, maybe I am wrong

          • curtains won’t work in the space unfortunately. they do make windows with blinds installed inside but that’s not the kind we have. whoops.

          • Havemeyer

            So the space is broken and that’s why curtains won’t work? Surely, you can repair it, you just renovated a house!

            No, seriously, I don’t care, do what you like, it’s your house! The full window gives you an unobstructed view, and that’s not a bad thing.

    • Thanks cmu for a sensible post. Providing an air-tight seal for your building envelope minimizes heating/cooling fluctuations and the associated energy costs. It also has an additional benefit of keeping unwanted moisture leakage, which can be trapped inside causing molding problems and other particulates.

      And those complaining about the double hung windows, as cmu pointed out, you can easily can fake muntins to achieve the same architectural look.

      As a side note, I don’t quite understand why so many on this forum is so resistant and skeptical to change and/or technology. It must be the generational gap or ignorance. What’s so wrong about looking at changes which can potentially make your life better and as well as improving the environment?

  • daveinbedstuy

    I think with the right facade, like this one, the single pane windows look a lot classier.

    I assume these are fixed pane, not casements, which would open. Opening the windows in the Spring is really part of what life is all about.

  • daveinbedstuy

    Also, as the pics point out, most of the “airtightness” comes from the installation using tape and rubber membranes. You can get an airtight window with double hungs.

  • Has anyone noticed that mold issues became all the rage around the time we started hyper-insulating? I lived in London for three years where it’s very wet, the houses are old and drafty and mold is only an issue on newer homes. I’m no fan of cold, drafty houses, but tight houses with no air changes and heat recovery ventalators introduce many concerns that must be addressed. I question if the energy savings are overshadowing the issues with humidity control, ventalation and something that looks pretty.

    • It is like having a bathroom and never opening the window. taking hot showers and no new air comming in or old air going out, will cause mold.

      Luckily I have a bathroom window which is full size since it is in the front of the building, and have a fan in the top half that exausts the steam right out. never had a problem with mold in 25 years, or poo mist for that matter.

  • daveinbedstuy

    pmorita…may I call you Pat????

    Yes, airtight houses still need an efficient exchange of fresh air. I had that problem in a house I have with all new, extremely energy efficient windows and spray foam insulation.

  • Dibs, Maybe I’m behind the times, but

  • Dibs, Maybe I’m behind the times, but

  • …. doublehungs seals lose efficiency over time as they lose tension/shrink/warp. Casement or other hinged styles seal with pressure as they close and don’t change over time.

  • callalily

    You all might be confusing passive houses with replacement windows, which are a total fraud. They look horrible, don’t last for very long, cannot be repaired, and aren’t more energy efficient than an original window plus storms.

    It would be dreamy if new construction didn’t need any boilers or heating source at all, and if the surroundings were built to be walkable and with excellent public transportation. Not only would this make life pleasant, inexpensive, and lovely, but it would create lots of jobs. If the NYT is to be believed, the passive houses are built to allow a high degree of fresh air replacement, and the air is heated (naturally, with people’s body heat) before it comes in, so there isn’t an issue with ventilation — supposedly.

    All that said, I plan to keep living in my leaky old house with a skylight and humid dirt floor cellar and don’t plan to insulate because I think the system works well as designed. I use incandescent light bulbs too. I’m wishing I had kept the gas system.

    Single light windows as above do not look right on old houses. I certainly hope no one will be forced to convert, but I’m sure they’ll find a workaround — such as the fake double hung windows. Another reason to expand the historic districts.

  • callalily

    I do have one question though: How to cool the upper floor in the summer? If you add HVAC, you increase your energy use. Our entire house (1890s) is one system for heating and cooling. The floors, doors, windows, attic, dirt floor basement are all related in a passive cooling system.

    • The PH windows do open, you know. No different than your house. But PH will require much less cooling due to insulation. You cannot argue with facts, in this case, studies showing the super-efficiency of PH.

      And I don’t get the replament window comment…what’s the difference between new & replacement wndow performance (the same brand, of course)? Unless you mean replacement installers do a shoddy job.

    • The PH windows do open, you know. No different than your house. But PH will require much less cooling due to insulation. You cannot argue with facts, in this case, studies showing the super-efficiency of PH.

      And I don’t get the replament window comment…what’s the difference between new & replacement wndow performance (the same brand, of course)? Unless you mean replacement installers do a shoddy job.