Los enfoques críticos y los procesos de emancipación

Overview

LEED v4 is a “performance-based rating system.” It’s easy to visualize and measure the performance of water and energy systems, but what does resource performance look like?

LEED has shifted the focus away from single attribute resource performance to incorporate all aspects of the environmental impacts from a material’s lifecycle.

The Materials & Resources section is shaped around lifecycle thinking at both the whole-building and product levels. Lifecycle thinking refers to the entire span of existence from resource extraction to materials processing, product manufacture to construction, and building use to building demolition or deconstruction. The comprehensive goal of the credits in the new LEED version 4 is to encourage as much materials reuse as possible.

Lifecycle thinking helps to overcome questions about end of life value. For example, whereas a material made from recycled content may perform quite high with respect to new resource extraction, it may not be particularly durable and therefore will require replacement much earlier than a material that’s built to last. Using lifecycle thinking, the LEED v4 credits will consider a complete, holistic picture of a material’s life, whether it be made of recycled content, salvaged from the existing building, or a bio-based resource.

When we’re talking about lifecycle thinking, we’re not talking about any one phase. We want to incorporate all of the steps from raw materials to operation, and look at a full comparison of product options.

Why is LCA a useful tool? It helps you see these tradeoffs and helps you look at the whole picture and not just one aspect. It helps you see across all these different stages. It gives us scientific methodology for doing these calculations and making these decisions.

Of course, it’s only one decision. You’re still going to look at the product’s performance, other technical requirements, and the cost. LCA helps you have an environmental metric to add to your equation when you’re trying to decide what you want to do. It gives us the framework to have an apples to apples comparison on some of these products as well.

Overview

The Materials & Resources credit category has 2 prerequisites and 5 credits.

 MR Prerequisite 1 Storage and Collection of Recyclables

 MR Prerequisite 2 Construction and Demolition Waste Management Planning

 MR Credit 1: Building life cycle impact reduction

 MR Credit 2: Building product disclosure and optimization – environmental product declarations

 MR Credit 3: Building product disclosure and optimization – sourcing of raw materials

 MR Credit 4: Building product disclosure and optimization – material ingredients

 MR Credit 5: Construction and demolition waste management

LEED v4 aims to increase market demand for manufacturer transparency. The MR section contains credits specifically aimed at building product disclosure and optimization.

Life Cycle Analysis

We can use LCA in a number of ways. We can look at it in a component and element level and we can look at whole building assessments. We can then actually understand how that transfers into our existing buildings and we can make sure we can understand that we can make better decisions when we refer to those buildings.

In LEED what we have at the Building Level is a whole building LCA, where the building is the product. In this case, the architect can be the LCA expert as the architect understands how the building is constructed, how building materials and products flow to the job site and how the building is going to be operated over time.

At its core, LCA is defined at the material level. It is not likely that an architect or any building industry consultant would be called on to produce material-level Life Cycle Inventory data. This information is calculated by process chemists, chemical engineers and submitted for inclusion in various LCI databases that companies producing product LCA data use as a resource.

MR Prerequisite 1 | Storage and Collection of Recyclables

The intent of this prerequisite is to reduce the waste that is generated by building occupants and hauled to and disposed of in landfills.

Requirements

Provide an appropriately sized area that serves the entire building for recycling. You must collect the following streams of on-going consumables: paper, corrugated cardboard, glass, plastics, and metals. The recycle bins must be distributed throughout

the whole building. Make recycling as convenient as possible. Think about ways to make the recycling stations convenient and they will be used more frequently.

Hazardous Waste

In addition to the ongoing consumables, the prerequisite requires safe collection, storage, and disposal of two of the following hazardous waste sources: batteries,

mercury-containing lamps, and electronic waste. Since these waste streams are limited and infrequent, a single collection point for the whole building is reasonable.

Electronic waste includes discarded office equipment (computers, monitors, copiers, printers, scanners, fax machines), appliances (refrigerators, dishwashers, water coolers), external power adapters, and televisions and other audiovisual equipment

Implementation

Provide well written signs placed in plain view make it easy for occupants to know what can be recycled, and where the materials should be placed. For example if you have a blue plastic recycling bucket with a label that says ‘aluminum cans’ on it, chances are nobody is going to throw cardboard into it.

Convenience is one of the most important factors for getting employees to participate in the recycling program. In an office building, recycling areas could be placed in each office, and then have a collection area near where the garbage is picked up.

Successful projects provide instructions. Let occupants know about the recycling program, or else they will not know to use it.

If recycling activity disrupts occupants it can have a negative effect. Noise, foul orders, and air contaminants all need to be addressed.

Label the recycling areas and collection strategies on your floor plans as part of the LEED documentation.

Rating System Adaptations

Retail has an adaptation for this prerequisite. Retail projects must do a waste stream audit to identify the project’s top five recyclable waste streams. The idea behind the audit is once again ‘you can’t manage what you don’t measure’. By analyzing the waste streams, retailers can get a better idea of where the waste is coming from and how best to divert it.

The waste stream audit must be conducted over at least one 24-hour period. Once the audit is complete, list the top four waste streams for which the project will designate collection and storage space.

To review those numbers: identify the top five recyclable waste streams over at least a 24 hour period. Provide dedicated and accessible collection areas for at least the top four waste streams identified in the audit.

MR Prerequisite 2 | Construction and Demolition – Waste Management Planning

The prerequisite is simply a plan, not a requirement to meet any thresholds or percentages of diversion rates. Projects need to report the diversion rates at the end of the project.

In 1996, 136 million tons of construction & demolition (C&D) debris was generated – 57% by non-residential construction. Most of this waste could have been recycled, thereby reducing the demand for virgin materials. Waste reduction by recycling C&D debris can also turn a cost into a savings for builders. Instead of paying haulers to dispose of C&D debris from a job site, the materials can be sold to a recycling facility, or given to a recycling facility in exchange for free hauling.

There are more than 6,000 centers around the United States that run specialized programs for reusing building materials. These programs are run by groups such as Goodwill, the Salvation Army, and Habitat for Humanity and include using unneeded materials in schools.

Document a Plan

Project teams must develop and implement a construction and demolition waste management plan. The plan must:

1. Establish waste diversion goals for the project by identifying at least five materials (both structural and nonstructural) targeted for diversion. Approximate a percentage of the overall project waste that these materials represent.

2. Specify whether materials will be separated or commingled and describe the diversion strategies planned for the project. Describe where the materials will be taken and how the recycling facility will process the material.

Provide a final report detailing all major waste streams generated, including disposal and diversion rates.

Educate and Collaborate

Establish requirements for waste reduction. First, make waste reduction a priority from the onset of the project and include it as a priority throughout the inception, design, implementation, and occupancy phases of construction.

Secondly, establish specific waste reduction benchmarks and goals for each phase and assemble a team of qualified professionals experienced in environmentally sound design and construction practices to see it through. Identify materials that can be salvaged and reused. Include these goals and requirements for experience in requests for proposals and other contract documents.

Monitor and support the program. Continually monitor the progress of waste reduction efforts by requiring contractors to submit the waste management plan and waste

management progress reports. Support these efforts by identifying locations to collect and store recyclables on-site.

Architects, designers and specification writers also have specific roles in the process.

They need to identify opportunities for waste reduction. Work with owners and developers to identify opportunities for waste reduction and public relation benefits.

Select a contractor with proven waste reduction experience. A contractor experienced in reducing construction waste will keep the bid the same or may even lower the bid. An inexperienced contractor may increase the bid.

Use a Construction Waste Management Specification. A Construction Waste Management Specification written with legally enforceable language is your most effective tool to ensure waste reduction happens successfully on your project.

It is critical to monitor the waste reduction program. The architect and designer play an important role in assuring the contractor’s compliance with the waste reduction program.

These individuals are responsible for requiring and reviewing waste management

progress reports and invoices from recycling and garbage haulers and recycling facilities.

By successfully monitoring the progress of the program and potential barriers, they can lead the discussion about the waste reduction program during the project meetings.

MR Credit 5 | Construction and Demolition Waste Management

This credit builds on the prerequisite. For this credit project teams are recycling and/or salvaging nonhazardous construction and demolition materials.

 Option 1: Diversion can earn 1 to 2 points.

 Option 2: Reduction of total waste material can earn 2 points.

Option 1 | Diversion Percentage

Path one requires a 50% diversion of at least 3 of the material streams selected from the plan created for the prerequisite.

Path two requires a 75% diversion of at least 4 of the material streams.

LEED defines material streams as material flows coming from a job site into markets for building materials. For LEED a waste stream should constitute at least 5% by weight or volume of the projects totaled diverted waste. This can represent either a material category that is diverted in the specific way or a mixture of several material categories that are diverted in a specific way. For example if you are separating out wood and concrete into separate bins on site those are each considered one stream. If you have a mixed bin with both wood and concrete for offsite recycling that is considered one total stream.

Option 2 | 2.5 pounds / squarefoot

Option 2 requires generating no more than 2.5 pounds of construction waste per square foot (12.2 kilograms of waste per square meter) of the building's floor area. For this option you don’t have to go through the diversion process.

Exceptions

There are some things you can’t include in the calculations. Excavated soil, land-clearing debris, and alternative daily cover are all excluded from the calculations.

Implementation

Implementation is about good practices and identifying ways to divert waste from

landfills. What a good general contractor is going to do is find places to take the material other than just throwing it to a debris bin and sending it off to the dump.

Project can have separate containers (wood, drywall, metal, etc.) or have a single container for vendors that do commingled recycling. Regardless of your choice, your documentation has to be either in weight or volume.

If you have a service that does commingled recycling for the project, they can provide you with a log once they take the debris away. The vendor can provide you with the actual log on how much materials you have recycled and how much was trash.

If you're going in and doing demolition and there is a lot of carpet, many carpet factories will take that carpet and pick it up, sometimes for free. Make sure you quantify it. In a case where you can grind up the material, such as asphalt or concrete, and use it onsite,

that counts as well. Donate to Habitat for Humanity or other causes as long as the debris is documented and you know what it weighed or what its volume was.

Onsite, the containers need to be labeled appropriately. Hazardous materials and land-clearing debris doesn't count against you. Make sure you're using just the trash containers onsite.

Source Reduction

Eliminating waste at the source, known as source reduction, saves money and valuable landfill space. There are many opportunities to implement source reduction strategies on construction sites. The total waste generated by a project can be greatly reduced by considering waste generation during the design phase, employing conservative purchasing practices, and by reusing excess materials at the jobsite.

Before construction begins, a construction waste management plan should be developed that identifies potential waste streams and where waste diversion can be put in place – salvage this waste, reuse it, and recycle it. If the waste can be taken out of the building and reused elsewhere, it avoids waste disposal in landfills and incinerators. Be sure the plan is actually put into practice and that the team tracks the waste through reports from the waste haulers to check that the waste management plan is actually working.

Advocacy

Work with suppliers to streamline purchasing:

 Request materials come with minimal or no packaging.

 Purchase previously used or salvaged items (most building owners will welcome the opportunity to save money while conserving natural resources).

 Determine where existing policies and procedures might represent a barrier to purchasing used or recycled materials.

 Keep a binder of information on product specifications and prices and check back with manufacturers regularly for updates.

 Document product performance, especially when materials exceed expectations or require special handling; establish a “feed-back loop” with the manufacturer by reporting usage information to them.

 Ask suppliers to take back or buy back damaged or unused materials and packaging

 Streamline supply estimations; make sure orders do not exceed your requirements.

Waste prevention can be more beneficial than recycling because it identifies potential waste early in the design process and decreases waste generated during construction.

 Design with standard sizes for all building materials. This avoids creating waste when standard sized materials are cut to unusual lengths.

 Design spaces to be flexible and adaptable to changing uses. This avoids creating waste during remodels.

 Design for prefabricated components. Modular building components, or products that don’t need to be trimmed down onsite reduce waste.

Documentation

From your vendor you need waste haul tickets.

Even though the project might extract soil and land, that doesn't count against the project.

If you're taking out some trees with clumps of dirt, that won't count against you. This credit is focused on the construction materials. Actual land clearing wouldn't count against the project.

If you have 30-yard dumpsters and you fill that up with wood, the calculations can be all volume in cubic yards, or weight. From experience, the weight usually is going to be the better measurement.

Waste-to-Energy

For some projects, waste-to-energy might be an option if reuse or recycling is not an option. Waste to energy focuses on the potential to improve the sustainable management of waste in Europe's regions, and to produce energy from waste. Directive 2006/12/EC of the European Parliament establishes the legislative framework for the handling of waste in the Community.

It defines key concepts such as waste, recovery and disposal and puts in place the essential requirements for the management of waste, notably an obligation for an

establishment or undertaking carrying out waste management operations to have a permit or to be registered and an obligation for the Member States to draw up waste

management plans.

It also establishes major principles such as an obligation to handle waste in a way that does not have a negative impact on the environment or human health, an encouragement to apply the waste hierarchy and, in accordance with the polluter-pays principle, a requirement that the costs of disposing of waste must be borne by the holder of waste, by previous holders or by the producers of the product from which the waste came.

Case Study

The Boston Scientific Company undertook the renovation of a two-story, 30,000 square-foot office building as Phase 1 of a 2-building, 400,000 sq ft project. The general contractor was Payton Construction Corp.; SOS Corp. was the demolition subcontractor.

The project involved gutting and replacement of interior furnishings and fittings,

wall/partition systems, HVAC, electrical, plumbing, and membrane roof. The project was particularly complex because renovation began at the same time as demolition, so that employees could move into parts of the building while other areas were still in

construction. The project was carried out to LEED Silver.

The Total Waste Reduction was 92% (702 tons recycled, 62 tons disposed). The Cost Savings was $49,983, or 63%.

Loading dock space was a particular problem, with only two dock slots which had to be reserved for the receipt of new materials as well as all outbound shipments. This was the only location from which wastes could be shipped. The large footprint also entailed long carry distances from locations where wastes were generated.

The team addressed this problem by mobilizing over 200 wheeled, soft-sided hampers holding 15 to 20 bushels (about 1 cubic yard) of wastes, along with four-wheeled rigid dollies to handle bulky materials like studs and partitions. These were spotted at individual work locations, where employees deposited specific wastes into designated containers. Full hampers or dollies were wheeled and staged in the shipping/receiving area. When wastes accumulated in a quantity to fill a dumpster or rolloff, the appropriate container was brought to the dock, loaded, and removed, taking up dock space only for the short time needed to fill the container. Using the hampers and dollies also made for a very clean work site; because wastes were picked up as they were generated, with none left on the floor for later collection.

MR Credit 1 | Building Life Cycle Impact Reduction

The intent of this credit is to encourage adaptive reuse and optimize the environmental performance of products and materials. This credit can earn up to 5 points.

Four Options

 Option 1 historic building reuse can earn 5 points.

 Option 1 historic building reuse can earn 5 points.

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