How Green Is Your Building’s Wood?

How Green Is Your Building’s Wood?

Using wood offers many sustainability benefits. Besides adding strength to a structure, and beauty both inside and out, wood is a renewable, reusable and recyclable resource. Wood requires less energy and water to produce than residential construction alternatives such as concrete, steel and plastic. Trees remove carbon dioxide from the atmosphere, and finished wood products store carbon. A long-term forest management policy aimed at maintaining or increasing forest stocks, while producing an annual sustained yield of timber, can generate significant green house gas mitigation benefits.

The environmental attributes of wood for construction of homes has been measured and found to be superior to alternatives such as steel and concrete. The United States Green Building Council’s Leadership in Energy and Environmental Design (LEED) program recognizes wood for green building, especially if it is grown within a few hundred miles of where it is grown. As an extra measure of assurance, some architects, developers and builders specify that wood products are certified by an independent third party as coming from sustainable forests. Among some 40 different certification programs worldwide, The American Tree Farm System, Sustainable Forestry Initiative and the Forest Stewardship Council are examples of organizations which offer certification verified by third-party auditors to ensure that sustainable forestry practices are followed.

How can architects, developers and builders know for sure that lumber for building their projects comes from sustainably managed forests? Sustainability is defined internationally as: meeting the needs of the present generation without compromising that ability for future generations.

Translated to forestry, sustainability strives to balance the interdependent and sometimes competing interests of the environmental, economic and social benefits that forests provide. That means harvest sites must be replanted, and that other assets of the forest— soil and water quality, fish and wildlife habitat, and recreation opportunity, among them—must be protected.Small and large landowners alike manage some forests for specific purposes. Thinning Douglas-fir and trimming lower branches allows specialty stands to grow more quickly and produce clear wood with few knots producing wood highly desired for windows and decorative construction.

An ideal way to ensure that wood is harvested in an environmentally and socially responsible manner is to choose wood from a state with strong forest practice laws. Tough standards and regulatory oversight offer assurance that comprehensive rules are followed and enforced. While other states may follow best management practices, their guidelines are not codified into law. And wood from international sources may have even far less environmental protection.

On working forestlands, good forest practices require that some trees and snags be left behind during harvest for wildlife habitat purposes. Along with buffer zones along forest streams, road-building activities must be approved under law and water runoff after harvest from the state’s plentiful rainfall is closely monitored to safeguard future forest resources. Key regulated practices and a host of other laws govern road construction, bridges, culvert placement, public safety, stream enhancement and wildlife protection, and include:

•Landowners must replant the forest within two years after harvest.
•Within six years, the harvest site must regenerate into a healthy trees.
•Live trees, snags and fallen logs must be left after harvest to provide wildlife habitat.
•A buffer of trees left alongside fish-bearing and drinking water streams,to ensure cool, clean water.
•Timber harvesting, road building and using herbicides are restricted close to streams
•Except when approved under special conditions, a clearing cannot exceed 120 acres.
Working forests are lands managed primarily for wood production. and which ensure that trees are replanted after harvest and that buffer zones protect forest streams.  Once trees are harvested, how green is the next stage? Timber manufacturing sector made early investments in technology for making raw logs into finished lumber. Timber is processed in high-tech, low-waste mills where lasers scan logs in three dimensions, computers decide the maximum number of boards, and every inch of log, down to the chips and sawdust, is put to use. Mills in the United States and Canada, often generate their own electrical energy from these wood by-products. How far must the wood be shipped to reach your project? The United States imports some one-third of its wood supply, mainly from Canada. It takes large amounts of fossil fuels to transport wood, and thus local sourcing is another factor of sustainability. Wood harvested within a 500-mile radius is the standard for defining "local."

How green is your building's wood? Green comes in many shades. But architects, developers and builders can feel assured of sustainability using wood products that are locally grown and manufactured, and that are grown in places with stringent and comprehensive laws that govern the practice of forestry.

LED Street Lighting Reduces Costs

LED (light emitting diode) is a solid-state semiconductor device that converts electrical energy directly into light. Its development started in the 1960s and has been typically utilized as indicator lights in numerous electronic products, signage and flash light applications. Just in the last few years as its technology advanced, LEDs are now used in real lighting such as traffic lights and brake lights/tail lights (take a look at those dotted brake lights in many of the new car models). Unlike conventional light bulbs, LED lamps use less energy and are more efficient, safe, and durable. So far, LEDs still cost more upfront (just think about how much you pay for a LED flash light vs. a flash light with a standard light bulb). However, the energy savings in the long term can result in tremendous savings; not even mentioned is the reduction in CO2 emissions. Furthermore, with their directional light beams, LEDs used for outdoor lighting can reduce light pollution since we can direct more light to the streets rather than towards the sky!
Ann Arbor, Michigan has been piloting LED street lights for several years now. The first pilot project replaced all the “globe” street light bulbs in the downtown area. It is indeed a successful project. Per the City, the initial installation will save the City over $100,000 per year in energy costs and reduce annual greenhouse gas emissions by 267 tons of CO2. Below is the detailed cost comparison by the City of Ann Arbor.



LED "Globe" Light Life-Cycle Cost Analysis

Existing Light Bulbs Over 10-Year Span Number Unit Cost Total Cost

Bulb replacements (2 year life) 5x $37 =  $186

Bulb labor & equipment 5x $211= $1,056

Ballast (10 year life) 1 x$59= $59

Igniter (10 year life) 1x $35= $35

Energy cost (4,380 kWh) - - $325

Total Cost = $1,661





LED Bulbs Over 10-Year Span Number Unit Cost Total Cost

Bulb replacements (10 year life) 1x $460= $460

Bulb labor & equipment 1x $56= $56

Energy cost (2,100 kWh) - - $182

Total Cost = $698
10-year bulb, assembly, and maintenance savings: $820
10-year energy savings: $143
Total savings: $963

* As Per the City of Ann Arbor: “Each LED replacement bulb saves $962 in energy and maintenance costs over its ten-year lifetime. At this savings rate, the new bulb pays for itself in 4.4 years ($423 / $96).” [This is how the 4.4 years is calculated: Bulb cost/ yearly saving = ($460-$37) / ($962/10 yr) = 4.39 year]

The biggest saving is the maintenance cost. Getting a crew on a lift to replace street light bulbs and parts is not cheap. Reduced maintenance cost is sufficient to make LED fixtures cheaper on a life-cycle basis than do conventional fixtures. In addition to the “globe” street light project, the City of Ann Arbor also plans to replace the conventional “cobra-head” type of street lights. Evaluation of LED cobra-head street lights started in 2005. The City installed the first LED cobra-head street light sample in the City Hall parking lot and the finding was that the “the new technology was not ready at that time.” However, as the technology improved on light output and color rendition in the past few years, the possibility of installing reliable LED cobra-head street lights was becoming more of a real option. Thus, the City started the second test trial by inviting several more LED manufacturers to provide more LED cobra-head street lights for evaluation while the City installed the lights at its own expense.  Wattages in this new group of LED cobra-head test lights varied from 50 to 80 watts as compared to the existing 250-watt fixtures. The City has been conducting its own evaluations which include a four-part assessment: light output; heat management (very critical to the lifetime of fixture); energy consumption; and general public input. The test is still on-going now.

The  experience with the test lights is very positive. The low-wattage LED lights are so bright that you could not tell the differences between the LED lights and the conventional street lights other than the appearance since these lights look so unique. So far, the following manufacturers are involved with trial testing: Holophane, IntenCity, Leotek, Lumecon, Millenia Technologies, and RUUD from Canada.

The LED light colors are all like blue/white except for one that is like blue/purple. The public comments so far are overwhelmingly good but some people did complain that the lights are kind of “harsh” and few neighbors complained that they lost free “night lights” because the LED light provides a direct light beam rather than a spreaded light beam. It may affect driving only at certain angles but it is no different than that of the conventional street lights. The LED technology definitely still has room to grow in uniform luminance distribution, but the energy saving, low maintenance, and environmental friendly advantages will make LED street lights the preferable option in the near future.

New Directions for Living Roofs and Walls

New Directions for Living Roofs and Walls

The evolving technology of green roofs has been leading to the use of greater diversity in their designs. After years of implementing green roof designs, the international industry has seen a steady move towards more diversity in both elements of construction and plant materials. What is most fascinating of the improvement in green roof design is the use of plants on these roofs which, along with other naturally decomposing materials, aid in greater biodiversity. No longer are sedums the only plants that are being used on green roofs. At the EcoBuild Conference in London 2010, exhibits featured new green roof designs showing a greater use of ornamental grasses and other flowering plants including some bulbs. The exhibitors even hinted at the use of materials that compose brown roofs. A brown roof is comprised of loose material as in crushed concrete or woody debris. This material can be combined with some self-seeding plants or left for nature to care for; however, the belief is that brown roofs will colonize spontaneously and will also provide habitat for several local species (i.e., bats, birds) as well as migrating species.

These new projects are so diverse they can help to support a large population of invertebrates including bees, wasps, and spiders.In addition, we see a growing interest in living walls. Living walls! What are they? They are walls of plants that can be free standing, attached to a building or built on a structure. Living walls come in many varieties. There are self-established walls, moss gardens/mat, climbers, and those derived through other technologies, such as hydroponics, modules, or cells. These walls provide many of the same benefits as a green roof would, in that they can help cool down an area, provide health benefits, and can aid in the reduction of heat and air-conditioning while creating greater habitat for birds and many invertebrates. Living walls can also assist with dust suppression, noise abatement, evaporative cooling, and shade provisions.The thermal benefits of vegetation along walls can maintain a temperature of 30° Celsius (C) when a road or non-vegetated wall reaches a temperature of around 46° C. Living walls are wonderful because they can be so diverse. As mentioned earlier, there are many types and we can grow a wide range of plants on them. Some, like self-established walls, are easy to maintain and relatively inexpensive. Take an ordinary rock wall and overtime, seeds will drop or land on it and take root. They can become quite thick with plants but they are slow to establish and may not do well in sunny, dry locations. They will, however, offer a great diversity of plants, if allowed. Climbers are limited to those plants that will climb exterior walls or wired structures, which limit the range of plants that can grow on them. With hydroponics, modules or cells exciting walls can be created that allow for plant diversity, unique designs, and creative arrangements. Although these systems are expensive, require irrigation systems and may require specialists to install and maintain, they can add a very attractive element in a design and can enhance indoor and outdoor spaces tremendously.

The wall provides visual interest, aids in scaling the size of the building to create a space for people to sit or stroll along while having a pleasant and positive experience.

Germany and Austria have been the leaders in green roofs for many decades now. In Linz, Austria, all new construction built after 1985 must have a green roof installed on it. The change has been remarkable. Green roofs and living walls are beneficial for our environment in reducing urban heat island conditions, reducing dust, cooling spaces, and habitat for several species in an urban. India too needs to include more green roofs and living walls in new construction and in existing construction by offering subsidies and other fiscal incentives to local and regional government agencies. We need to continue to raise the public’s awareness to get the support of policymakers.