Wednesday, November 9, 2016

So what is a Passive House?


Way back in 2012 we moved into our newly renovated townhouse here in Hoboken.  It was built to the Passive House standards and I had planned to do a post about this type of construction... well, better late than never!

Hudson Valley Field House          Madison Passive House         Jersey City Victorian

Here are three Passive house projects we have currently in the works...yes, THREE!   We'd like to share those with you as well in the coming posts... a residential gym under construction in the Hudson Valley, a ground up modern farmhouse in Madison, NJ and a modern Victorian renovation just completed in Jersey City.  The house under construction in Madison will be on the International Passive House Days so you could take a tour this Saturday from 10-2pm!



We've always been excited to spread the word about Passive House but it feels like we are at the tipping point of this becoming a mainstream approach to construction.  Not to say this methodology is easy to execute, but once the architect and builder are committed to the type of care and attention that is required, there really is no reason not to do it if you are doing an extensive renovation or building from scratch.

Here's a basic rundown to understand what it takes to be a Passive House...


1) Super Efficient windows.  We often hear that clients think these windows will be way more expensive because they are typically European.  The reality is that they are comparable, if not cheaper, than quality windows made in the USA.  And companies here in the States are starting to figure out that there is a market for a highly engineered window.  Not only are these windows triple glazed, they are designed to be airtight and thermally effective at their frame as well.



2) Contiguous envelope of insulation.  There are so many great options for insulation these days that getting a high thermal value is not the hard part.  The trick is in making it a continuous barrier. Think about an outlet in an exterior wall that has no insulation behind it, but just sheathing... we don't like that!  Or a beam that starts outside and comes inside with no break, carrying with it all the cold.  A double wall is how you achieve a thermos like enclosure. Either on the inside like the front of our house that had existing brick or on the outside.  We did the latter on the Passive house we are working on in Madison, NJ...



3) Sealing every nook and cranny.  Air leakage causes drafts which make us feel cold. End of story. This is as simple as knowing how to specify the right kind of tapes and air barrier and have them detailed properly in your wall assembly.  You know the house is tight after a blower door test where negative pressure will tell you if you have any leaks and where they are.

Blower Door Test at our Hoboken Passive house

4) Energy Recovery Ventilator (ERV).  You've sealed the house so well that now you need fresh air. This magic box brings in fresh air 24/7 but before doing so, it exchanges the heating or cooling of your inside air.  Voila, magic!  Change your filter every 6 months and you have fantastic air quality all year long.  That's something we can all appreciate.

ERV Installation

5) Good architecture.  This is the stuff we do regardless of the type of construction. Where do you place windows when you live in a seasonal climate to maximize heat gain in the winter and minimize it in the summer?  How do we promote air flow on those beautiful days when the windows are open?  How do you layout the spaces so there is an open airy quality allowing for views and light.


And here's an example of looking at each condition in a house and how to make it better architecturally and thermally.  The photo below is of a two-story bookcase we added after the photo above was taken. Not only does it display a ton of books we had in storage, it also allowed us to insulate behind it where there cold was conducting through the masonry wall that continued from the outside to the inside.  And yes, from the first and second floor we manage to reach all the books!



Exciting stuff, right?!  Well, it is exciting when you have a $20 heating bill in January.  Or you're still warm when the rest of the town is freezing because you lost power in the latest Noreaster.  Not to mention blocking street noise and dirt... and who wouldn't want that?  So our Jersey City clients said 'Sign me up!" ...we'll share more on this house in our next post.

Jersey City Passive House


1 comment:

  1. This comment has been removed by a blog administrator.

    ReplyDelete