Welcome to DCD, home of the number one construction magazine!
Welcome to DCD.com!

 Current Issue
 Click here to
 read the issue.
Click Here To Access The DCD Archives™
Subscriber Login

   Current Issue
   Issue Archive
   Specifiers Spotlights
   Building Products Revue
   Technical Articles
   Case Studies
   DCD Sq. Ft. Cost Guides

   Cost Trends

   Media Kit

   Free Subscription
   DCD E-News Subscription


D4COST Software


Click Here to
Subscribe Today
for Your FREE
DCD Magazine

Knowing How to Measure a Green Building can Help Sell Renewable Energy
By Paul Nutcher, CSI CDT

The renewable energy industry could benefit greatly by targeting green building projects. This is true for project teams setting up systems for distributed renewable energy generation on building sites, the manufacturers of the system components, and many other ancillary businesses with a stake in a building’s energy performance. Furthermore, if the diffusion of renewable energy technology has been slow to gain market traction, the LEED program could be a significant driving force for expediting the growth of BIPV and utility scale installations, as well as other renewable generation systems and energy storage systems.

Commercial buildings in the United States consume 18% of the nation’s energy and are responsible for 18% of the nation’s carbon dioxide emissions, according to the Department of Energy. The residential building sector consumes 22% of electricity and contributes 20% of the carbon emissions, as reported during the Energy Programs Consortium presentation February 2008: “Income, Energy Efficiency and Emissions: The Critical Relationship.” With renewable energy providing less than 10% of the electricity in the US, the building sector of the economy has as much growth potential for renewable energy product manufacturers as the transportation and industrial sectors of the economy.

A realization that buildings needed to become more energy efficient and healthier for their occupants, while reducing their impact on the environment, sparked the earliest stakeholders at the non-profit US Green Building Council (USGBC) to take steps toward addressing more sustainable buildings. The result of those first steps was a program to measure a building’s energy and environmental performance. Today, the most widely recognized national rating tool for third-party verification of a sustainably designed, built, operated, and maintained building is the LEED Green Building Rating System from the USGBC, which first introduced the first of its family of rating programs in 1999. Marketing to the green building industry will take effort from stakeholders in the renewable energy business because they will first need to understand how such energy systems can enhance a high-performance building project—which under the USGBC program results in “LEED certification.”

A LEED score
LEED stands for Leadership in Energy and Environmental Design, and measures the environmental impacts and energy performance of buildings as two of its fundamental goals. The LEED family of green building rating systems contains sets of voluntary performance standards, many of which have become mandated by city and state governments, as well as most federal agencies. The Government Services Administration (GSA), possibly the world’s largest landlord overseeing courthouses, offices, agencies, among other federal buildings, requires a LEED Silver certification level. The LEED for New Construction v. 3.0 (LEED-NC) rating system is divided into five main categories including sustainable sites, water management, energy and atmosphere, and indoor environmental quality. There are also two other categories for exemplary performance including the Innovation in Design and Regional Environmental Priorities categories for capturing ways in which the building significantly out performs the benchmarks in the first five categories or addresses a regionally specific environmental issue (i.e. water conservation or diverting materials from landfills).

On-site generation of electricity from the sun, wind, or other natural sources have the greatest opportunity for assisting building project teams within the Energy and Atmosphere Credit Category of LEED. Most points in the rating system assigned to any of the categories are in the Energy and Atmosphere category, with a possible 1-19 points for Optimizing Energy Performance, another seven points are possible for incrementally larger percentages of energy usage from renewables, and the project team can gain even more points toward LEED certification for purchasing green energy credits. Because may renewable energy systems measure the output of the energy system, other credits dealing with the commissioning and verification of a renewable energy sources can offer further LEED points. The amount of possible points in the Energy and Atmosphere category is significant because it only takes 40 points for certification. So, the LEED point totals typically shoot high up the scorecard when renewable energy equipment is installed on LEED buildings. Many gain LEED Silver, Gold, or Platinum certification levels. For reference, the highest LEED Platinum certification is between 80-100 points.

On-site generation of electricity from the sun, wind, or other natural sources have the greatest opportunity for LEED points in the Energy and Atmosphere Credit Category. IB Solarwise™, a photovoltaic (PV) system converts sunlight directly into electricity and works with commercial, industrial, and residential applications.

But there is still a catch. Before even considering going for LEED, there are prerequisites in all but the Water Management, Innovation in Design and Regional Environmental Priorities categories. The important one here is the energy efficiency benchmark, ASHRAE 90.1-2007. Plus, the energy systems must be commissioned by a third-party to verify the performance of the HVAC system and no CFCs are permitted in the cooling system. Once the prerequisites for the energy systems have been met, the higher the percentage of energy optimization the building is designed to achieve the more points it will gather. Should the building go beyond 40% energy efficiency above the benchmark, there is another point available in that sixth category: Innovation and Design, for example.

Retrofitting renewables
LEED Green Building Rating System has separate programs for covering the two phases of a building’s lifecycle, one for new construction (Schools, Core and Shell, Retail, Homes, Neighborhoods, and there are more in development), and one for ongoing maintenance and operations of a building after the construction phase. The LEED for Existing Buildings Operation and Maintenance (LEED-EBOM) rating system follows a sustainably built structure to the end of its useful lifespan and the rating tool can be applied once the building has been occupied for at least a year. The point structure and categories are a bit different as the LEED-EBOM rating system is more focused on post-occupancy issues, such as efforts to reduce peak energy demand, save on utility bills, and reduce the carbon footprint of a building or real estate portfolio.

Though teams constructing new buildings are the focus of the LEED-NC program, property managers, real estate portfolio owners, and other building industry practitioners looking for a larger return on investment after a renewable energy retrofit installation will decide whether to go for LEED-EBOM. The rationale for LEED-EBOM to this market segment is that properties certified by the USGBC stand out in annual performance reviews, annual budget planning sessions, and add a premium to leasable space. The LEED-EBOM certification process can also identify deficiencies in standard practices that need correction, and then provide the best steps toward operational improvements. An annual re-certification of LEED-EB status from the USGBC may extend the lifespan of a structure because the rating tool can help in the development of a system to avoid a decline in building maintenance.

Renewables & LEED for existing buildings
Between 1-18 points are available in the Optimized Energy Efficiency Performance category in the LEED-EBOM rating program. During commissioning and energy audits, inefficient areas of the structures’ operations are pinpointed and monitoring of energy consumption on major mechanical systems is initiated and a program for ongoing monitoring begins. The number of points earned is contingent upon a facility’s EPA ENERGY STAR rating or the percentile level above the national median.

LEED points are earned when increased levels of operating energy efficiency can be documented and, as a result, reduce the environmental impact of excessive energy use. A facilities manager can also purchase Green-e certificated energy (a similar option for project teams on new construction), to gain points for helping reduce greenhouse gases and by helping to develop a market for renewable energy. Points are also available for continued commissioning of the building performance.

New industry products can be applied to new construction and re-roofing low-sloped roofs maintaining the natural look of the property. The IB Solarwise™ PV system installs over existing roofs with no demolition and disposal costs and includes a 20-year warranty covering roof material and energy performance.

During this process, the building’s capabilities, advantages, and weaknesses are assessed by the commissioning agent so financial costs and benefits are calculated. Training programs are developed and building operating plans are updated. Using an ongoing commissioning program that reflects changes in an existing facility’s occupancy, usage, maintenance, and repair needs ensures adherence to stated revisions and upgrades. Periodic adjustments and reviews ensure optimal energy efficiency. The on-site and off-site generation of renewable energy can also gain from 1-6 points toward LEED-EBOM certification. It is up to the energy consultant to determine whether solar, wind, biomass, geothermal, and biogas technologies are the most advantageous.

Conserving through greener site development
The amount of radiant heat from the sun penetrating the building envelope and the thermal transfer properties of the hardscape can all impact the energy efficiency of a building. LEED programs recognize this strategy for overall reduction of energy usage on the property. The impact a rooftop solar array has on the performance of the building envelope is good to know when trying to sell a building owner on the systems. In fact, a tax credit from the Energy Policy Act of 2005 provides up to $1.80 per square foot for the developer, based on improvements to the building envelope and another 60 cents each for installing more energy efficiency for lighting and HVAC systems. Renewables can have an impact on gaining the tax credit by powering a portion of the energy needed for lights and conditioning the interior space.

Other site credits with implications for the renewable energy product manufacturer include the designation of parking areas for plug-in electric hybrid cars, among other strategies for reducing carbon emissions from fossil fuels. Indirectly, less energy is needed when building project teams design and build for a reduced impact on the heat island effect. The rooftop configuration of a solar array can have a significant effect on how the thermal gradient differences in urban areas versus undeveloped areas will be addressed. Again, any assistance here from a renewable energy installation should be communicated to the building team prior to the pre-design phase of a construction project to improve the chances that the associated products and services will be specified in the construction documents.

The future of LEED
The LEED rating system (or an equivalent rating tool, i.e. GreenGlobes, ICC 700) will one day become the standard that most governments set for project teams wanting a permit to build. Looking at the current building codes in most of the country, with the exception of governments that have already adopted LEED as the standard for getting a building permit and there are many already, some people may ask why we didn’t build like that all along? Much of the intent of the LEED credits are a throwback to the way the building industry was headed decades ago, but a mindset of unlimited energy and materials took over. LEED appears to be here to stay and not a moment too soon as the world gears up to address climate change. All of these efforts could help the long term prospects of renewable energy product manufacturers, especially those who take the time to understand how their products enhance LEED green building projects.


Why More Projects Are Using PVC Membranes

Its durability, fire resistance and proven track record all make PVC (polyvinyl chloride) membranes a desirable choice for building owners and manufacturers alike. It is a high quality, aesthetically appealing product that builders can use with peace of mind knowing that it can be easily recycled, as well as helping to reduce waste and save energy.

First introduced to North America in the 1970s, the use of PVC membranes in low-slope roofing has grown significantly. Many PVC roofs installed over 20 years ago are still performing today, proving their durability and resistance to contaminants.

Three of the most defining characteristics of PVC membrane are its heat weldability, its reflectivity, and its durability and resistance to fire, resulting in it being increasingly chosen over TPO (thermoplastic polyolefin). It is incredibly user friendly and there are a variety of attachment methods for installation. The versatility of vinyl also allows it to be designed with enhanced chemical resistance, flexibility and/or tensile strength, making it a smart choice for builders.

The thermoplastic properties of vinyl enable it to be fused together into one continuous membrane. “Thermoplastic” means that when heated enough, the material transforms temporarily into a semisolid state, allowing two sheets or panels to be overlapped and fused together. During this process, heated air is injected into the seam area, softening the membrane surfaces. The seams are then pressed together with a roller as it quickly cools, and the heat weld is made, providing a watertight bond. This bond is what makes PVC so resistant to leaks and weather conditions that take a toll on a roof’s longevity.

In addition to the importance of heat-welded seam technology, vinyl roof membranes have many other important attributes that have spurred its growth in the industry. One of those attributes is durability. PVC has met or surpassed many industry performance standards involving water leakage; puncture resistance, resistance to hail and wind-uplift resistance. It is also exceptionally resilient under ponded rainwater, and other typical rooftop contaminants such as air pollution, acid rain and bird droppings.

Resistance to fire is another reason builders will decide to use PVC membranes. Vinyl membranes are inherently self-extinguishing, enabling them to perform exceptionally well in fire tests designed by organizations such as Underwriters Laboratories and Factory Manual. PVC surpasses these tests, and performs reliably in real-world flame exposure as well, giving building owners added peace of mind knowing their money spent on a new roof was well-invested.

PVC has a great versatility of application, but it is also aesthetically pleasing. Vinyl membrane manufacturers, including IB Roof Systems, offer a surface treatment that resists dirt attraction to enhance the look and visual appeal of the membrane. PVC membranes can be produced in a variety of colors to suite the building owner’s needs. This feature allows for the application of rooftop logos or multi-color roofs. It can be produced in a reflective white, or other attractive colors to blend in with the surrounding environment. The reflective properties of white PVC make it an attractive choice for its ability to adapt to a wide range of temperatures, significantly reducing a building’s heating and cooling costs.

PVC is not only versatile under many contaminants and weather conditions, it has various attachment methods and accessories that add to its diversity. During the application process, vinyl membranes are usually mechanically attached, adhered to the insulation or other substrate or held in place with stone or concrete ballast. Some manufacturers, such as IB Roof Systems, even offer all of the above attachment methods allowing it to be installed on virtually any low-sloped roofing project. In addition, vinyl membrane can be produced with “fleece cushion” backing, enabling it to be installed over rough surfaces or adhered with a variety of adhesives.

PVC is fully recyclable, particularly the excess material that occurs during the production process. These trimmings can be recycled back into the roof membrane or can even be reprocessed into another end-use product such as rooftop walkways or roadway patch materials. Under a new program, many vinyl membranes have the well-known Energy Star label from the United States Environmental Protection Agency (EPA) and the Department of Energy (DOE), assuring building owners that their roof membrane meets the required energy saving specifications. An all-around good choice, PVC membranes are cost effective, easy to install, and good for the environment.


©2015 Copyright DC&D Technologies, Inc. All rights reserved. | DCD Construction Magazine | Email: webmaster@dcd.com