In new construction the thermal barrier in the attic should be verified by an attic insulation certificate.
This house is supposed to be Energy Star compliant for Virginia standards. As such there are criteria that are to be met. For example, windows and doors should have certain U-factors and solar heat gain coefficients. There should be foam sealant around windows and door framing, and gaps in exterior walls. And the insulation in the walls and ceiling should meet certain criteria. There are more criteria.
And everything is supposed to be inspected and verified by someone who insures that Energy Star criteria are met.
One of the things that is to be verified is the attic insulation.
The certificate is supposed to be placed in a visible location, typically near the attic access opening, and it is supposed to indicate lots of things.
This certificate states the insulation manufacturer, Knauf, which is a good company. And then states that the minimum insulation depth is 13" and gains an R-value of 38, which is the minimum R-value for Virginia's Energy Star standard.
Simply writing down an R-value and depth is useless. That R-38 value is possible at 13", but only at a very high density which insulation companies would never use when installing insulation. Typically the density they claim to use is .55 Pounds per Square Foot (PSF). But that is suspect. My experience is that they load the insulation with lots of air to gain a fluffy depth and then that air settles over time so the actual insulation depth is much less.
But if you go to the Knauf website and look at their insulation chart click here they state that in order to get R-38 a minimum SETTLED depth of 14.75" must be used, with a density of .7 PSF.
And I measured the insulation randomly in three places and got a depth of 9", 9" and 10". And this is recently-placed insulation! It will take a while, usually about a year, to settle as the air comes out.
But my client is supposed to believe that an Energy Star certifier has looked at this and verified that it meets the R-38 criteria. I think not!
My recommendation: insulation is a very important thing to look at during a new construction inspection! And I do. Builders have contacted me in the past to dispute what I have said in inspection reports. But I don't invent anything. I simply report what I see. And what I saw here was the same as I saw the other day, with the same certificate, with the same useless information. That's a pattern! And it is not hard to add to what is there now. And it should be done, along with proper verification.
Jay Markanich Real Estate Inspections, LLC
Based in Bristow, serving all of Northern Virginia.
Office (703) 330-6388 Cell (703) 585-7560