How to Build a Better Home – Wall Construction and Insulation



hello I'm Helen ray Nikki wilt of Arlington County's initiative to rethink energy and green home choice program you're about to watch one of a series of videos we call how to build a better home the story of the construction of a passive house we hope you'll find some useful tips about making your home greener and more cost efficient whether you're building a new home or simply upgrading your present one here's green home builder patty shields of Metro green with today's tips on wall construction and insulation it's about lowering your energy bills consume less energy and water we take up a little less carbon footprint more comfortable and super quiet you will reap the rewards for the life of the home I think it'd be great if people see homes like this and think about green design when they're building out this paddy with Metro green and we're going to talk about passive house building construction now the wall construction what what's really important in wall construction for passive house and really any house is the thickness of the wall and making sure it's well insulated this house here is a 2×4 constructed wall it's got another two by four on the outside which gives us a total depth of 10 inches in 1940 1960 and 1970 from Maine to Florida we built our houses just out of two by fours okay there's no difference in fact today we often build our houses just out of two by fours whether you're in Maine or Florida we're building it the same way but we don't have the same heating and cooling needs we do in Maine as in Florida's in North Carolina as we do here in Virginia we were always building our furnaces and our mechanical systems to meet that size of the house and the needs of the house with this two-by-four construction with Passivhaus we're flipping that around and we're saying let's build the envelope or the wall of the house to meet the mechanical system instead of build a mechanical system to meet the construction or envelope of the house in Virginia based on entered energy model we've determined that 10 inches is the ideal wall depth for a passive house wall in North Carolina it might be 8 inches in Maine it's 14 inches so here we have built two construction two walls the inside is a 2 by 4 the outside is a 2 by 4 and they're separated by a few inches of space these are actually 3.5 inches with additional few inches of space in between to give us that full 10 inches what this space does is this gives us what's called a thermal break meaning that no heat or cold is being conducted from the exterior of the house through the wood all the way to the interior instead we're putting insulation here that takes care of that and make sure that we don't conduct that heat or cold to the interior of the house this is a pretty simple way to build it's affordable and cost-effective and what a homeowner can do today green home choice program and Energy Star what they're promoting is going to a two by six stud and putting foam on the exterior of the house but this is also another affordable way to build a house that gives you that kind of insulation value that green home choice Energy Star and indeed Passivhaus are looking for when we were framing the house I showed you we were doing a double wall construction and you can see that here but now you can't see the double wall because of course we have it packed with insulation so here we have 10 inches of dense pack cellulose cellulose is dense packed cellulose is is essentially recycled material newspaper or other sorts of products that gets blown into first they put this netting on the wall and then they blow in this cellulose to a certain density 3.5 pounds in this case and so we have 10 inches of dense pack insulation here which provides us in roughly an hour 38 wall assembly code compliant is our 13 I believe so you can see this about three times what you would have in a normal house built today another point on insulation when you're constructing a house in between each floor you have the floor joists and that's these here and the problem when you're insulating the house is normally you insulate between these these studs but how are you going to address in between the floors and so we address that in most houses in most modern applications today your insulator or your Builder will suggest putting in foam spray foam at the band joist of the house and the band joist or what we call those things like that run around the rim of the house at each floor all of this is all the way out to the outer edge of the house providing a quite a bit of insulation make making sure that entirety tire cavity is full and maximizing our insulation on the band's and a lot of older houses there is no insulation at all in these locations thanks for watching this is Patti shields with Metro Green homebuilders join us again next time for another segment on how to build a green home thank you if you would like more information on the green home toys program please visit our website at Arlington energy dot us slash green home choice or call us at 7:03 two two eight four seven nine two for the air and green home toys programs i'm helen Reineke wilt

9 Comments

  • seumas2

    April 13, 2019

    For infinitive details on how to build A PASSIVE HOUSE see Port Alberni's first passive home in the Heart of Vancouver Island BC Canada/ 30 videos to date from the foundation up as the build progresses to the finished stage / google search seumas2 in youtube in the top bar open up videos, slainte mhath

    Reply
  • David Grounds

    April 13, 2019

    A 6 1/2" Structural Insulated Panel from R Control will get you a R 22 at 70 degrees and R25 at 25 degrees. Add BASF graphite increases R value to 30-33. A whole lot less material, labor and carbon foot print to manufacture extra material.

    Reply
  • John Ellis

    April 13, 2019

    In Empire USA, over 99% of exterior walls are built of 2×4 construction, with only 5 inch total depth and with 40% of wall having zero insulation. For 15% of wall is windows and doors, and 25% of wall being solid wood from siding to the drywall. Surely, 99% of modern homes have a wall R rating of less then R10. And so, place 1.5 inches of polystyrene sheets on the inside and outside of all wood components, which will increase 25% of wall surface from R7 to R22. This will increase the insulated cavities from 3.5 inches to 6.5 inches, and cavity R rating from R13 to R24. Do this and your wall R rating will jump from R9.5 to R25.5

    Reply
  • technosaurus

    April 13, 2019

    If you are going to build a double wall, why not do staggered studs? It gives you an even better thermal break. With staggered studs you can even separate them with sound isolation panels and still have a thermal break. There is a guy in Missouri that is doing just that but for his insulation+isolation he's using recycled cardboard soaked in a saturated solution of boric acid (I think for fire, mold and insect treatment) He says the R value is as good as traditional cellulose and it is great for noise reduction (Not to mention really cheap and "green")

    Reply
  • wilwad

    April 13, 2019

    Thank you.

    Reply
  • George Ashing

    April 13, 2019

    Adds strength to your house too ?

    Reply
  • Adriano Suella

    April 13, 2019

    I'm using 6x16cm structure filled with cellulosa. OSB inside and a false wall of 6cm filled with rockwhool, then a fermacell fibreboard. This space could be also empty, depending on your insulation requirements.
    Outside a 6cm thermal coat made by fiberwood attached direclty on the structure.
    I think might be more expensive to build two walls.

    Reply
  • soulless one

    April 13, 2019

    Cellulose is garbage you do all the extra work to fuck it up

    Reply
  • Johnintoit

    April 13, 2019

    I know I posted on one of your other videos and asked why not use closed cell over dense pack cellulose? cost?

    Reply

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