construction waste in the urban environment grows quickly with demolition

Demolition in the urban environment adds significantly to construction’s waste stream. (Copyright: mariok / 123RF Stock Photo)

Construction Informer Podcast

Building anywhere is complicated by all the construction waste created during demolition, and again while building. The urban environment has its special set of challenges related to construction waste, but, in some cities, it also has distinct advantages.

Listen in as Patti Mason, the U.S. GBC  Colorado chapter executive director offers her perspectives on construction waste, LEED, and LEED’s relevance as standards bodies and building codes adopt green building principles.

Listen to the Podcast, right now. Or – Read the transcript just below the player.

[You can listen to, or read, the first podcast in this series, right here.]

[And, here’s a link to the third podcast in this series.]

[Part 4: Building in the Urban Environment: Earth Sensitive Design]

Podcast Transcript

Welcome to the Construction Informer podcast.  Right at the start I want to say, that it’s been a couple of years since I did podcasting here.  But I’m going to revive that a little bit and use podcasts to focus on some particular themes in the coming months.  In this case, the theme is “Building in the Urban Environment.”

And, we’re focusing on that because all indicators point to a major population shift moving to the cities. So that means more urban construction and exponentially more of the challenges that come with building in the urban environment. And, this episode is all about dealing with the construction waste on projects that happen in densely packed the areas. And you know in many parts of the country, up to 50% of the waste that’s going to landfills comes from construction activities. And because construction waste has a lot of air in it, it takes up a lot of landfill space. Just to give you an example.  On average it takes a little more than twelve yards of construction waste just to make a ton. Now that’s only about 166 pounds per yard. Just compare that to gravel, where each yard weighs about 1.5 tons.

Now, much of construction’s waste stream is truly waste because it also includes so many perfectly usable materials. All you have to do is watch the home improvement shows and you can’t help but notice how demolition has become a form of gleeful entertainment. From smashing cabinets and countertops with sledgehammers, to front end loaders tearing into whole houses, the message is clear.  It’s tear it out, destroying it in the price, and throw it away. This really isn’t  sustainable, and it gives the industry a bad rap.

But as difficult as it is to manage the construction waste stream in  suburbia, just imagine how tough it is in the inner city. So here to help us sort out what’s going on with construction’s waste stream from the perspective the LEED ( Leadership in Energy and Environmental Design) which is an initiative of the United States Green Building Council, we have Patti Mason, the U.S. GBC  Colorado chapter executive director.  Welcome Patti.

Thank you so much for having me.

I see that you were named executive director in June I guess it was right?

Yes that sounds about right.

But I guess you were with USGBC since 2008?


And you have a master’s degree in natural resources. Now is that kind of like the study of the natural environment I guess, from a resources perspective?

Yeah absolutely.  So I studied natural resources law and policy here in Denver, at the University of Denver. And it was in that program where I learned all about the impacts of our built environment, and the resources that they consume. And I had very little previous background in construction or real estate or anything like that, but it was kind of the lightbulb moment for me when I have always been you know an environmentalist, at heart, and wanted to combine that spirit with something that could be, a big practical job like working with the US Green Building Council, and working with an industry that doesn’t necessarily share some of the same environmental thoughts and beliefs that I have. But being able to kind of work alongside businesses in the community of green builders that we have in Colorado has been a great fit for me… kind of marrying up of those two interests in terms of helping improve the environment but then also advancing policies that will help that as well.

Well you know I’m sure it’s been eye opening to you too. You know, when it comes to resources, construction uses a lot of them but it also seems to waste a lot. Can you give us some perspective about the importance the U.S.G.B.C. gives to waste reduction during construction? And then maybe kind of going a little further, maybe you can tell us a little bit about how the demolition waste from existing structures can count toward LEED certification because it seems sometimes that’s confusing for people.

Sure absolutely.  So in many ways the U.S. Green Building Council was one of the original reasons that contractors were challenge to start recycling construction waste materials, above and beyond just metal. And so I think you can really see how a rating system like LEED, in assigning certain points to things like construction waste recycling has created this process and this desire for general contractors to kind of get on board on a project and show what their value is in terms of helping an owner achieve sustainability goals.

Due to LEED requirements, contractors created some methods and means for tracking, to make it possible, and in and many cases easier  for them to go about achieving some ambitious sustainability goals on projects.  So we see a lot of general contractors in our community having pretty sophisticated spreadsheets, and processes for managing waste on a site, and in monitoring that in order to achieve the points that we’ll talk about here momentarily.

You know they have to have pretty detailed information about what they were able to do, in weighing of different materials, and signed contracts from haulers, and things like that, that really help create that paper trail that can then go and help the contractor demonstrate back to their owner and the team, that you know, they really were a part of achieving that LEED plaque at the end.

LEED also created a market for demolition materials as building reuse is also encouraged, and by encouraged I mean get  points if you were able to go into a building and actually keep some of the building in renovation projects. And even major renovation projects, sometimes are able to achieve points for leaving like the skin of the building intact, and going in and just maybe gutting out the insides.

Here in Denver Colorado, and in the lower downtown in particular, that’s been a really popular strategy because the historic buildings are the ones that tenants are looking for the most these days, and especially ones that look historic on the outside. But you get on the inside and it has all of the technologies and modern finishes that you would want for an office space. So that’s another way that LEED absolutely can help.

As far as specifics, construction waste either during demolition or during the project itself, can count for two credits. You get one credit for reaching fifty percent of construction waste recycling. Or two credits if you can get up to seventy five percent of your construction wastes recycled. And you would demonstrate that, typically it’s done by weight. So you weigh what is your total waste. That’s one number, and then what is the amount of that number that was able to go into a recycling option versus into the landfill.

And do projects in urban areas tend to go for the waste reduction points more often, or in greater numbers, then say projects in other environments?

And so, yeah, it’s an interesting thing and again being from Colorado we are very in tuned to this issue because urban projects tend to have the resources available to recycle. We have haulers that are familiar with requirements for lead certification and other requirements. We also have recyclers more commonly located in denser areas in urban places. And projects in other environments, and in our rural communities can definitely achieve credits, but they sometimes will lack those local programs and the local market that they need for different materials that come off of the site, like wood for manufacturing and drywall for soil amendments. So we see some interesting recycling in some of these markets being created in urban areas because that structure, that business model has been created here already.

Whereas when I talk to people on projects outside of urban areas they sometimes have to let those points go because if you think about the larger environmental impact of say hauling a recyclable material a significant distance in order to justify a LEED point, well that’s kind of robbing Peter to pay Paul, right, that’s not really the true spirit of what we’re trying to do with the rating system. Though that of course would be an option, but oftentimes those points aren’t going to be achieved because of either the distance it would take to haul the material, or because, again, there isn’t any kind of secondary market readily available in the community to give that by-product to.

Teams are encouraged to get creative, though, you know, and that’s the most exciting thing is to see how LEED and other programs are encouraging that creativity and creating the synergy between one person’s trash and another person’s treasure, you know, finding those connections between different materials and it’s really fascinating and something that Colorado and a lot of states in the West are addressing right now.  We have urban areas, and then we have large vast areas of much more rural and suburban areas that lack the synergistic opportunity.

Sure, sure, and it sounds like some of the urban areas they probably have more methods for dealing with the waste then say some of the rural ones. But there’s probably unique challenges in that urban area. What would you call some of that for contractors?

So the most common one that I hear about is the the tight site. So if your adjacent site is a, you know, a twenty story skyscraper, and the other side of you is another skyscraper, or even a privately owned parking lot, you lack the space available to actually have the proper recycling and haulers right there on site to do the best job with this.

So limitations on space and room to sort construction waste on site is absolutely a challenge in urban areas. And the way that we’re seeing this most commonly addressed is using commingled dumpsters and then sorting the waste off site with offsite labor or even more recently now mechanically. So technology and waste management technologies have come so far that there’s this thought around that perhaps we should let a machine do our recycling for us because we’re often confused on what goes into which recycling, you know. So commingling I think is one really common strategy that we see that allows for that dumpster to be sorted somewhere off site by either a laborer off site, or even potentially some sort of mechanical solution.

And then I’d say one of the most effective ways to reduce has me thinking back to what we all learned about recycling. First we want to reduce, then reuse, and recycle is kind of the very end. So to reduce that construction waste is prefabricating offsite. There’s a lot of opportunity with prefabrication on things like bathroom groups, or even exterior skins can come onto an urban site already assembled and ready to go. And you’re seeing a lot of that also in residential construction where prefabrication can help kind of lower the amount of construction waste in general. And materials can then be more thoughtfully planned out and again help really reduce the amount of waste that we generate in the industry.

Yeah and that’s a continuing trend for construction, to move more toward manufacturing kind of principles, actually.  Now, the green building movement is in full swing. There’s new standards coming out from both new and old standards bodies. ANSI for example just released its national green building standard draft for public review.  And of course we have municipalities and localities getting into the act too that are issuing their own sets of standards. I was wondering, can you put LEED into context for us in relation to how these green building standards are evolving.

Sure.  So you know when this first started coming out I think a lot of people looked at USGBC and wondered what will happen and where will LEED be as we start to codify LEED strategies.  And we opened our arms and we’ve been at the tables with all of the code adopting bodies encouraging that because the adoption and enforcement of green building standards and codes fundamentally advances our mission to transform the way our industry designs, constructs, and operates buildings. We aren’t here just to capture the top tier buildings. We really are an organization that believes in the true transformation of this industry as being our end game, and in order to do that, again, you really have to work with the folks that are going to only design and build what is absolutely required by code.

And by getting more of our green building strategies and proven approaches to this, into code, is a great thing and something that USGBC is absolutely encouraging, supportive of, and investing in itself. You know, historically building codes have been implemented to prevent building failures and cataclysmic events like fire and structural collapse, things you know  that are really scary. And I think when you see green codes it’s a new change for us and for the industry especially because it’s now accepting the fact that the risk of our built environment is no longer just to prevent fire and other types of natural disasters. There’s a human impact on the built environment and USGBC’s been waving that flag for a long time now, saying that the impacts on the human as well as the planet need to definitely be taken into consideration.

So I really get excited about the introduction of things like the national green building standard, and ASHRAE 189, and the international green construction code. These are all positive signs that LEED does work. LEED is getting the design professionals, the contractors, it’s getting all of us to apply strategies that go far above and beyond what is already required by code. And then it’s even taking some of those most proven practices and putting those in the code, and that’s where the magic happens because ultimately what we want to see is not just buildings that do less harm to the occupant, or less harm to the planet, and can stand up for thirty, forty, a hundred years, but also buildings that are regenerative and potentially zero energy self-sufficient, and resilient, and can quickly get back online and back functioning in the time of a disaster, especially as we see more of these natural events happening.

I think the importance of things like green codes is becoming more and more clear. And then the importance of buildings being resilient and being able to provide water, and be able to run even though the utility is down in the community.  You know these are great things and again I applaud the national green building standards for working with us on getting some of the LEED strategies codified because you know that you’ve got to raise the floor if you want to you know raise the roof.

It’s got to be a group effort.  And you know clearly, clearly construction’s got plenty of opportunities to change its approach not only to how it builds in general, but how it handles its waste stream so I think there’s definitely interest there when you see all the efforts at codifying some of these best practices, I guess you’d call them.

Well, I want to thank you Patti for taking the time to share some perspectives, and to you listeners thanks also for tuning in, and until the next time…  build it well!

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