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Green Building Curmudgeon

Multifamily Green Building Certification Still Has Issues

We’re making progress — but for many designers and builders, there is still a long way to go

Oops! We forgot to insulate. The builder needed to install gypsum sheathing to fill a gap before installing the floor joists. Unfortunately, this approach left large uninsulated gaps that will need to be blown in later through drilled holes.
Image Credit: All photos: Carl Seville
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Oops! We forgot to insulate. The builder needed to install gypsum sheathing to fill a gap before installing the floor joists. Unfortunately, this approach left large uninsulated gaps that will need to be blown in later through drilled holes.
Image Credit: All photos: Carl Seville
Pulling back one piece of insulation exposes a large chase that is not properly air sealed at either the exterior walls of the chase or at the outside surface of the interior wall. These details should be better identified on the plans. The gable at the end of this vault is an attic kneewall that requires rigid air barriers on both sides and R-18 insulation. Neither the architect nor the contractor were aware of these code requirements. No matter how often we are told that the insulation installers know how to install insulation to Grade 1 specifications, this is what we see on almost every project. Identifying chases such as these in the design and estimating phase, and budgeting for appropriate air sealing from the beginning, will reduce delays and job site tension

Much of my work these days involves certification of multifamily buildings, and, thanks to a boom in apartment construction, my partner and myself are staying occupied.

The one major contrast from single-family residential work, with which I am most familiar from my days as a contractor, is the long lead time. I still find it amusing that I sign a contract, have an initial start-up meeting with the developer and contractor, and often don’t see the project for another year or more, when the builder is ready for our insulation and air-sealing inspections.

Due to this lag from start-up to our inspections, we can be suddenly quite busy inspecting buildings — often 3 or 4 in a single week. Just recently we inspected buildings in both Rome and Athens — but, unfortunately we never left the state of Georgia.

Insulation is still the biggest challenge

Depending on the certification program (we work with LEED for Homes, the National Green Building Standard, EarthCraft, Energy Star, and Enterprise Green Communities), we have to confirm that insulation installation meets either Grade 1 or Grade 2 specifications for these projects to be certified.

In our initial meetings, we stress the importance of this, and urge our clients to consider something other than batt insulation due to the challenges of meeting the installation quality requirements. Unfortunately, the budgets rarely allow for these upgrades, so we constantly find ourselves struggling with the installers.

We always schedule a meeting before insulation work starts to review our requirements and to confirm that the installer can meet them. This is the point at which we start hearing the falsehoods. The managers always insist they have great crews who are fully trained to meet the Grade 1 standard, but inevitably when they show up on site, no one has discussed installation quality with them and they just start doing their regular old Grade 3 work.

I can’t blame the installers (at least most of the time), as many are paid on a piece-work basis and in most cases, they are not only not being paid enough for the quality work we need, chances are they were never told that the job required Grade 1.

Whole lotta firing going on

Our enforcement of insulation standards leads to a lot of friction on the job site. When you walk through a job and pull out about 80% of all the insulation for correction, you get some pushback.

Insulators complain that they aren’t being paid enough, builders complain that we are delaying their schedule, and we complain because we get all itchy from touching insulation all day. We have caused insulators to quit and get fired, and we have even been fired as consultants from a project because the builder blamed us for their delays.

The part about this that bothers us the most is that while we are enforcing green building standards, typically these standards are no more stringent than the energy code and the insulation manufacturer’s instructions. These instructions call for the equivalent of Grade 1 and all necessary air barriers.

Unfortunately, the baseline we are compared to is so far below these standards that many builders cannot easily get to where they need to be.

It’s the air leakage, stupid

Beyond the quality of the installation, we also find missing air barriers throughout the multifamily buildings we inspect.

Attic kneewalls (those walls that separate conditioned space from unconditioned attics) require rigid air barriers on the attic side and (in Climate Zone 3) a minimum of R-18 insulation. These details are rarely identified in the plans and specs, so builders don’t budget for this extra work. Elevator shaft, corridor, and stairwell walls need to meet the same installation specifications as exterior walls, and, due to scheduling issues, these are often insulated and covered with drywall before we get to inspect them. I have had contractors remove lots of drywall to have the insulation inspected (and corrected) in order to meet certification requirements.

Architects install all sorts of bump-outs that create chases in the exterior walls, many of which do not get the proper air barrier installed. I can’t count the number of times I have pulled out a piece of insulation to check the installation only to find a big hollow cavity behind it, missing all the required air sealing and essentially leaving a gaping hole in the building envelope.

Be afraid — be very afraid — of “value engineering”

One ongoing problem we find is “value engineering” during the estimating or construction process to lower construction costs — a common practice in the building industry.

The problem arises when the individual making the decision to make a specification change isn’t aware of the implications on certification. They might be able to save $100,000 or more by swapping out windows in a building, but, if the new windows don’t meet the minimum requirements, the building may not be able to be certified.

If there is a contractual agreement to have the building certified, a seemingly small change may end up costing more than it saves.

There is some hope

Green consultants who provide certification, are, in most cases, viewed as a necessary evil, often ignored by most of the construction and development team.

Raters and green consultants should be welcomed as key members in a project team – on an equal footing with the architect, engineers, builders, and others.

While we do see some progress – the occasional call from an architect or developer before their plans are complete – this does not happen as frequently as it should. When the design and development team understands what green professionals have to offer, and bring them in very early in the process, we will start seeing more buildings that are truly high-performance.


  1. kevin_in_denver | | #1

    I Don't Envy Your Tough Position
    Your work only benefits the building owner. Somehow the project management structure should connect you directly to him, as an equal to the GC.

    In multifamily these days, unfortunately, the building is sold as soon as it gets leased up.

    Value Engineering is an absolutely necessary evil. The architects control all the costs, but aren't very good at minimizing them. They don't understand the field assembly processes well enough, and these are constantly changing.

  2. fitchplate | | #2

    Validating a truth
    I think Carl’s blog reveals a truth that is oft unacknowledged and oft claimed to be in the opposite: the fact is, airtight and super-insulated houses costs a heck of a lot more per cubic ft and/or square ft than conventional builds. Convention is not defined by code, rather it is determined by local practice, designer/builder/home owner ignorance, and in many cases, what builders can get away with.

    I can introduce you to the highest caliber contractors in their areas of specialization who when building their own homes are clueless and even contemptuous towards air sealing, conditioned space ventilation management and superinsulation.

  3. stuccofirst | | #3

    For kneewalls, we do an air barrier on one side (pressure boundary) and a required moisture barrier on the cold side. Zone 5a

  4. GBA Editor
    Martin Holladay | | #4

    Response to Shane Claflin
    I'm not sure what you mean by a "moisture barrier" -- but I hope you don't mean a vapor barrier. On the cold side of a kneewall, you want either a vapor-permeable air barrier, or a thick layer of rigid foam.

  5. stuccofirst | | #5

    vapor retarder
    A high permeance vapor retarder correct?

  6. GBA Editor
    Martin Holladay | | #6

    Response to Shane Claflin
    By definition, a vapor retarder slows down the passage of water vapor. That means it has a low vapor permeance. You don't want a vapor retarder at this location.

    If you are installing some type of membrane at this location, you want it to have a high permeance. In other words, you want something like Tyvek or Typar, not polyethylene. Tyvek and Typar have a high permeance; they are not vapor retarders.

  7. user-1135248 | | #7

    A supporting anecdote
    Just yesterday I happened to be in a corner of a neighborhood that
    backs onto a fairly large commercial building that's undergoing
    renovation. Part of the wall didn't have its cladding yet and I
    could see a "wall of sprayfoam" two-plus stories high! Thought
    this was nice to spot, and was curious about the vertical white
    plastic-ish looking ribs poking through it on the surface. When
    I asked a couple of foreman-type guys standing next to the fence
    they said it was a waterproof membrane wrapped around the outer
    edges of the steel studs to keep them dry. And that's all that
    was going in under the outer metal cladding -- NO additional
    thermal-break layer of rigid foam on the outside of this stackup.

    My mind boggled. Do they still allow this? The guys were like
    "well, the smart guys design it, we just build it" but they seemed
    well aware of the issues already. Smart guys?! They filled [or
    almost filled, there were plenty of visible thin areas] all those
    stud bays with the most expensive insulation option and then left
    all the cold conduits to the interior sticking out in the raw.


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