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Community and Q&A

Energy-efficient doors

RWalterS | Posted in Green Products and Materials on

I live in New Hampshire and I’m looking for recommendations on energy efficient doors.  I will be installing triple pane vinyl windows on my project and soon I’ll be shopping for two entry doors and a hinged patio door for a walkout basement.  For my climate I imagine fiberglass but I’m open to suggestions.  My budget would be 4-5K.  All comments welcome!

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  1. Expert Member
    BILL WICHERS | | #1

    Who are you using for your windows? Many window manufacturers also make doors, so if you have that option I’d check with the same company that makes your windows for doors first. Everything will match that way.


    1. RWalterS | | #2

      I'll be using Matthews, and unfortunately they don't provide doors.

  2. Zdesign | | #3

    I was recommended by a manufactures rep to only have one opening panel on a double hinged door for my house. The reasoning was too much air infiltration especially during the blower door test. Having the one panel fixed cut down a significant amount.

  3. Expert Member
    RICHARD EVANS | | #4


    Obviously, you want a door with a triple locking mechanism for a better air seal.

    Koltech makes nice entry doors and have been used on Passivehaus projects. I believe they would be within your price range. There are two places that sell these doors (and others) near NH:

    1.) Pinnacle Windows in Augusta, ME. They do a lot of work in NH. (We used them for our windows. They are excellent!)

    2.) Loewen Windows in White River Junction, VT (right on the NH border). They sell more than just Loewen but will have these doors available.

    For my pretty good house in Sunapee, NH, we went with Thermatru doors with triple locks. We paid about 3k for 2 of them. (one is 8' tall). I think they were R-5 so not too bad. (I did see a bit of sunlight peeking through the gasket in one of the corners recently. We have a blower door test coming up which will tell us how problematic this is.) We purchased these through our local lumber yard (Lumber Barn). You can order them through Lowes or Home Depot as well.

    Our installer is named Brin Keegan who is based in Vermont. He did a great job and was very fairly priced.

    If you are really into doors and are willing to sell a kidney for them, then consider Hammer in Hand:

  4. GBA Editor
    Martin Holladay | | #5

    There is a GBA article that addresses your question. Here is the link: "All About Doors."

  5. Expert Member
    Michael Maines | | #6

    For affordable, reasonably energy-efficient, reasonably stylish (modern-looking) doors, I typically spec Thermatru Smooth-Star Fiberglass Flush-Glazed doors, with 3-point locks for long-term airtightness. They aren't super high performance, but fine for a Pretty Good House.

    If you want something more unique, check out this company:

  6. walta100 | | #7

    Just yesterday I was thinking how much I hate 2 of the 3 Thermatru doors I had installed. They happened to be installed in one of the few spots with only a small overhang. They leak water like a sieve 3 sets of weather stripping and warped hardwood floors later I gave up and covered them with storm doors.

    The doors glass claimed the same U value as all the other windows in the house yet the Thermatru are dripping condensation long before any other piece of glass in the house.

    Even with the threshold all the way down the sweep on the bottom of the doors are totally crushed and dragging on the door.


    1. Expert Member
      MALCOLM TAYLOR | | #8

      Blame your architect. I'm just finishing up the design of a house that has ended up with five exterior doors. Every one has at least a six foot overhang right above them.

    2. Expert Member
      Michael Maines | | #11

      Walter, I have had the same problem many times with Thermatru doors when there is not enough overhang. I've found it very helpful to install a rain deflector at the bottom of the door slab: It also helps to dig out the butyl caulking at the sill/jamb connection and re-do it with a heavy bead, running it up onto the threshold. A good sill pan with a back dam is a must. Ordering sills with long horns seems to help, as the outer edge where the sill meets the jamb seems to be a weak point.

  7. Expert Member
    Peter Yost | | #9

    HI Walter -

    One of my biggest regrets in my deep energy retrofit (see this GBA case study: is purchasing builder-grade ThermaTru doors. If did not take long for the doors to bow and lose gasket compression at all but at the lockset. Triple-locking mechanisms would have helped but you often get what you pay for: the Passive-House windows and doors with beefier frames, triple seals, and triple-points of compression locking make a huge difference, particularly over time.


  8. Stockwell | | #10

    I will pile on to the ThermaTru beatdown. My 2004-model house had these installed. As someone else mentioned, you could easily see daylight past the gaskets. No good. In the same house was an Anderson door which had an excellent locking mechanism and great seal. ProVia makes a great door as well.

  9. Expert Member
    Akos | | #12


    I've done this for an interior door to hide a fireskin retrofit, similar idea should work for an exterior door.

    Basically start with a standard door slab, add on the extra insulation you want, a layer of wood veneer and trim out the sides. Kwikset makes extension kits for their deadbolts for thicker doors. If you want to go fancy you can do the veneer/insulation section as an inset and add on secondary door seals.

    When on budget, I prefer metal skinned doors as the magnetic door seals are less sensitive to adjustment and tend to stay sealed in the long run.

    More of a DIY solution though.

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