Saturday, June 30, 2012

Parks as Urban Food Forests

Sandwiched between 15th Ave. S. and the play fields at the SW edge of Jefferson Park in the Beacon Hill neighborhood of Seattle are seven acres of lonely, sloping lawn that have sat idly in the hands of Seattle Public Utilities (SPU) for the better part of a century. At least until this spring, when the land that has only ever known the whirring steel of city mowers will begin a complete transformation into seven acres of edible landscape and community park space known as the Beacon Food Forest.

The end goal is an urban oasis of public food: Visitors to the corner of 15th Ave S. and S. Dakota Street will be greeted by a literal forest — an entire acre will feature large chestnuts and walnuts in the overstory, full-sized fruit trees like big apples and mulberries in the understory, and berry shrubs, climbing vines, herbaceous plants, and vegetables closer to the ground.

Further down the path an edible arboretum full of exotic looking persimmons, mulberries, Asian pears, and Chinese haws will surround a sheltered classroom for community workshops. Looking over the whole seven acres, you'll see playgrounds and kid space full of thornless mini edibles adjacent to community gardening plots, native plant areas, a big timber-frame gazebo and gathering space with people barbecuing, a recreational field, and food as far as you can see.

The entire project will be built around the concept of permaculture — an ecological design system, philosophy, and set of ethics and principles used to create perennial, self-sustaining landscapes and settlements that build ecological knowledge and skills in communities. The concept of a food forest is a core concept of permaculture design derived from wild food ecosystems, where land often becomes forest if left to its own devices. In a food forest, everything from the tree canopy to the roots is edible or useful in some way.

"If this is successful," explains Margarett Harrison, the lead landscape architect for the Beacon Food Forest, "it is going to set such a precedent for the city of Seattle, and for the whole Northwest."

Nation's largest public Food Forest takes root on Beacon Hill (Crosscut)

Friday, June 29, 2012

The Vertical Gardens of Patrick Blanc

Plants have found a home on walls for centuries, but are sometimes incongruous with architecture, often breaking down the structural integrity of a building’s facade. Patrick Blanc’s Vertical Garden System, known as Le Mur Vegetal in French, allows both plants and buildings to live in harmony with one another. The botanist cum vertical landscape designer is probably best know for his gorgeous living wall on the Musée du Quai Branly in Paris (shown above). But Blanc’s Vertical Garden System can be implemented anywhere: indoors or out and in any climatic environment.

The three-part system consists of a PVC layer, felt, and metal frame, providing a soil-free self-supporting system light enough to be hung on the wall, and even suspended in the air, weighing in at less than 30 kilograms per square meter.

The Vertical Garden can be used as an impressive outdoor system, or can be used indoors, with the help of artificial lighting. The natural benefits of the Vertical Garden are many: improved air quality, lower energy consumption, providing a natural shield between weather and inhabitants. No matter where you live, urban or suburban, cold or hot, indoors or out, the Vertical Garden brings a little bit of green to all.

Read more: Patrick Blanc’s Vertical Gardens (Inhabitat)

Patrick Blanc has always been fascinated by plants. He was a child he created his first tropical aquarium filled with exotic species. 

As a teenage student, the French botanist visited Malaysia and Thailand and noticed how plants grew vertically up cliffs, with their roots spreading inside the mosses on the rocks. 

Blanc tried to imitate what he had seen when he returned home. He covered walls with old clothes and encouraged plants to take root and climb, with the aid of an irrigation system at the top of the installation. He called it Mur Vegetale, the Vertical Garden. 

Mr Blanc has created hundreds of vertical gardens around the world, including a vertical Orchid Show, which has opened at the New York botanical garden. 

Walking among 4,500 blooming orchids and 30,000 plants - while wearing green shirt, shoes and even green hair - Mr Blanc told the BBC about his passion for design.

The 'vertical gardener' on creating urban rainforests (BBC)

Culture, Not Contraptions

Barcelona is a hot, humid seaside town where people have been deferring to heat for thousands of years....rather than rely on machines, and wreck their old architecture with window units and ducts, they design their habits, hardware, clothes, and attitude to cool themselves off. Now their deference seems sustainably avant-garde.

The secret to Catalan comfort is not a gadget, but a self-induced, mind-body state of discomfort suspension: heat tolerance. Accordingly they plan their seasonal vacations, daily routines, food, drinks and wardrobes for maximum cooling. In other words, it is the culture that cools, not the contraptions.


It is the antithesis of American life, which offers up every day as a shapeless continuum of snacking, working and shopping at 24-hour stores with season-free air.


What happens when humans treat themselves like dairy products chilled behind glass?

Civilization declines.

The proof is in Barcelona. Spend five glorious weeks in its barely mitigated heat, as I did last summer, then return home and refrigerate yourself in the relentless mono-temperature now anesthetizing the continent. Conclusion?

A/C is the killing frost sure to wilt the last fragile shoots of American culture. 

Keep Cool With Culture, Not Contraptions (Treehugger)

From Gangs to Gardens

Quesada Avenue, the block once known as the most dangerous in the area, has been transformed completely and now serves as a hub of community life. At the top of its hill, Jeffrey showed me the beautifully designed food garden for educating kids. Behind the chain-link fence, stalks of corn stood at attention beside a glowing patch of leafy greens.

At another garden a few blocks away—a patchwork of small plots that had previously been an improvised trash dump—a sandbox and rope swing indicated that the garden was for more than growing food. Kids, in fact, had painted the signs that ringed the garden’s perimeter with such slogans and quotes as “Don’t dump on my garden” and “If you want to change the world, start in your own neighborhood – Harvey Milk.”

Quesada Initiative’s success arises from the project’s appreciation of gardening as the means to an end more profound than a harvest of lettuce and peas. While the plants produced are of course a key motivation for any gardening enterprise, growing food can also—should also—serve other important social purposes, like cultivating a culture of civic engagement and an ethos of community participation.

“The change that we’ve created is not about the garden, it’s about the gardeners,” Jeffrey told me. He stopped to greet a neighbor as we rounded the corner back onto Quesada Avenue. As we continued on our way, he smiled at me with satisfaction.

“We realize we have done something right here,” he said.

From gangs to gardens: How community agriculture transformed Quesada Avenue (Yes! Magazine)

Urban Permaculture Strategies - Part 3 (Bill Mollison - Global Gardener)

Waste = Food

Once we start thinking in these terms, a possible solution can be expressed using a concept developed by William McDonough and Michael Braungart, shown here.

It is an elegant and compact way to express the concept that the industrial system must be conceived as an ecosystem. You know that the ecosystem doesn't run out of minerals, even though it uses minerals as nutrients for metabolic processes. That's possible because the ecosystem is a nearly completely closed cycle, that is what is "waste" for some organisms is "food" for others. Nothing ever can be 100% recycled, but the ecosystem comes close to that. The tiny fraction that is lost is slowly returned into the cycle by tectonic processes powered by the Earth's hot nucleus. The continents have been colonized by plants some 350 million years ago and plants have been "mining" minerals from the ground for all that time without ever running out of anything.

This is the way life works on this planet and if we want to survive we must learn from that. That is, we must learn that waste is food. Once you have that in mind, then you start understanding how wrong is almost everything we do with our waste. For instance, why do you want to incinerate your food? Why do you want to throw your food at the bottom of a pit and cover it with thousands of tons of dirt? You see, there are lots of things we must learn.

The other side of the peak: Long term tendencies of waste management (Cassandra's Legacy)

Thursday, June 28, 2012

When urban beekeeping gets too dense

Bees need a certain amount of nearby green space in order to find enough pollen to survive. Without that, bees can starve. They can also end up subsisting on a diet of syrup that's about as healthy for them as a diet of burgers and fries would be for you and I. London has had die-offs of bees in the past, when beekeeping got more popular than the city's limited green space could support. Some people are now worried that New York City could be headed toward that problem.

Two Years After Legalized Beekeeping, City May be Running Short on Forage (WNYC)

Sunday, June 24, 2012

Elephant Underpass

Road to Recovery?, National Geographic: An African elephant approaches an underpass beneath the busy Nanyuki-Meru road in northern Kenya...

 The first of its kind for elephants, the underpass will ideally provide a safe corridor for the large mammals to move throughout the Mount Kenya region (map), where highways, fences, and farmlands have split elephant populations, according to Geoffrey Chege, chief conservation officer of the Lewa Wildlife Conservancy, a Kenya-based nonprofit.

    Without the underpass, animals that try to move between isolated areas often destroy fences and crops—leading to conflicts with people.

    Since its completion in late 2010, the underpass has been a "tremendous success"—hundreds of elephants have been spotted walking through the corridor...

    At first, only adult male elephants ventured through the underpass, and then only at night.

    But before long whole family groups were passing through during the day...

 Currently the region's elephant populations are divided into two isolated groups: 2,000 animals in Mount Kenya and 7,500 in the Samburu-Laikipia ecosystem, according to the Lewa Wildlife Conservancy.

    The elephant underpass ... could improve the genetic health of northern Kenya elephants, since more genes will mix as the animals move into various territories and find new mates.

    The corridor may also mean that elephants will move around more, reducing pressure on habitats—and possibly helping other species that use the same resources, such as the black rhinoceros, according to the conservancy. ...

Elephant Underpass (Economist's View)

Saturday, June 9, 2012

Cross-Laminated Timber

Developed in Europe in the 1990s, cross-laminated timber, or CLT, is among the latest in a long line of “engineered” wood products that are strong and rigid enough to replace steel and concrete as structural elements in bigger buildings. Already popular in Europe, CLT is only beginning to catch on in North America, where proponents say buildings made with the panels could be a cheaper and environmentally friendly alternative to structures made with those other materials.

The panels use a lot of wood: A typical eight-foot-high wall can contain more than six times as much as one made with conventional framing using two-by-fours. But with proper forest management, trees are a sustainable resource.

Moreover, the buildings have a low carbon footprint: Because trees remove carbon dioxide from the atmosphere through photosynthesis, the carbon stored in all those panels helps offset the greenhouse gases released in making and hauling the other building materials and in the actual construction.

And by using so much wood, cross-laminated timber buildings might also help solve a vexing problem in North America: what to do with millions of pine trees that have been killed by a widespread beetle infestation but are still standing in Western forests, posing a great fire risk.

A tall wooden structure would seem to be a collapse waiting to happen, but a building made from cross-laminated timber is stronger than a conventional wood-frame structure, in which two-by-fours and other relatively small components are tied together by materials like plywood and plasterboard.

“That’s one of the things we found difficult to get across, that timber panel construction is completely different from timber frame,” Mr. Thistleton said. “It’s got more in common with precast concrete construction.”

The panels are built up from narrow planks, about an inch thick, that are laid side by side to form layers. Like plywood, each succeeding layer — there can be as many as 11 — is laid perpendicular to the preceding one. The layers are glued and the entire sandwich is pressed and trimmed. Then, using computer-guided saws and drills, it is cut to the precise dimensions in the architectural plans, including window, door, plumbing and ventilation openings. Channels for electrical wiring can be cut into the panels.

At the construction site, the panels are hoisted into position and bolted together with metal brackets to build up the structure floor by floor. Construction can proceed fairly quickly — the Graphite Apartments were built in about two-thirds of the time it would have taken to construct a similar building in steel or concrete.

Friday, June 8, 2012

The Living Technology of Christopher Alexander

Let’s start with the insight, Alexander says, that living systems are able to make extraordinarily coherent structures, like dragonflies, or roses, or humans. These coherent structures are remarkably well organized, and remarkably beautiful. (As we will see, that’s not a coincidence.) Biologists call this process “morphogenesis” — the generation of structures, in this case living ones.

Alexander proposes (on the basis of many others’ work in physics, biology, and cosmology) that these morphogenetic processes generating coherent structure are going on all the time — in fact, are at the heart of living processes, which are themselves more elaborate forms of the same kind of structure generation. So the capacity for morphogenesis is deeply ingrained in the structure of matter (both animate and inanimate) and nature, even if living organisms seem to be relatively rare phenomena.

Morphogenesis is closely related to ecological sustainability — the ability of organisms to maintain stability in the face of very dynamic and even hostile environments — because it is nothing other than the process by which living systems adapt to the changes that would otherwise destroy them. So it’s very important that we understand this kind of process, and understand how we do and don’t incorporate it into our own actions. Can our technologies and our way of making things reflect living processes? This includes our making of buildings, cities, and landscapes — Alexander’s primary focus as an architect.

If we don’t do this, then we risk creating fragmentations, rifts, disordering mechanisms. Up to a point, this may not matter — our environment has sufficient resilience to absorb minor disruptions. But at some uncertain boundary — perhaps a sharp threshold — we risk the collapse of critical systems on which our human well-being depends. That’s because fragmentation destroys the morphogenetic ability itself. There is ample reason to be alarmed that we are approaching just such a state today.

How did we get into this predicament? We humans are very good at assembling large complex structures from lots of standardized parts. We started doing it with rifles, where one rifle design was broken down into parts, and we could make thousands or millions of identical rifles from sets of identical parts. Following essentially this technique, we have built our world today.

Nature occasionally does something like this too, when it makes, say, billions of individual blood cells that are largely interchangeable — so much so that we can even swap them between certain people, and they will continue to carry out their complex processes and functions. In a similar way, a soldier can swap out his bolt assembly with another rifle, and it will still function.

Yet nature seldom works this way: every creation of structure is embedded in a context, with its unique circumstance, adaptation, and evolutionary history. Even in the rigid realm of crystals, there is mind-boggling variety among snowflakes, for example. If we could somehow swap out the arms of one snowflake with another, we would find that they never fit symmetrically. The context, not the thing, is the key. We might say: nature is complex — and all complexity is local!

When we create the parts of rifles or buildings, we treat the whole as being “composed” of its parts. But this is an abstraction: a whole is not simply the sum of its parts. Leaves do not “make” a tree. In fact, the tree makes the leaves! Each step of morphogenesis transforms a previous whole, in which the connected parts go through some kind of patterned restructuring. They may group together, they may differentiate, they may form various kinds of structured sets in relation to one another — but always, they do so in characteristic patterns, based on fundamental properties of space and the physical structure of the cosmos. The more important evolution occurs in the connections, though these are much harder to visualize.

The Living Technology of Christopher Alexander. Michael Mehaffy and Nikos Salingaros. Metropolis Magazine

Tuesday, June 5, 2012

NYC Gardens Urban Permaculture 1 (Bill Mollison - Global Gardener)

Roman Lighthose Still In Use

The Tower of Hercules (Galician and Spanish: Torre de Hércules) is an ancient Roman lighthouse on a peninsula about 2.4 kilometers (1.5 mi) from the centre of A Coruña, Galicia, in north-western Spain. Until the 20th century, the tower itself was known as the "Farum Brigantium". The Latin word farum is derived from the Greek pharos for the Lighthouse of Alexandria. The structure is 55 metres (180 ft) tall and overlooks the North Atlantic coast of Spain. The structure, almost 1900 years old and rehabilitated in 1791, is the oldest Roman lighthouse in use today. There is a sculpture garden featuring works by Pablo Serrano and Francisco Leiro.

The Tower of Hercules is a National Monument of Spain, and since June 27, 2009, has been a UNESCO World Heritage Site. It is the second tallest lighthouse in Spain, after the Faro de Chipiona. The tower is known to have existed by the 2nd century, built or perhaps rebuilt under Trajan, possibly on foundations following a design that was Phoenician in origin. It is thought to be modeled after the Lighthouse of Alexandria. At its base is preserved the cornerstone with the inscription MARTI AUG.SACR C.SEVIVS LUPUS ARCHTECTUS AEMINIENSIS LVSITANVS.EX.VO, permitting the original lighthouse tower to be ascribed to the architect Gaius Sevius Lupus, from Aeminium (present-day Coimbra, Portugal) in the former province of Lusitania, as an offering dedicated to Mars. The tower has been in constant use since the 2nd century and is considered to be the oldest existing lighthouse in the world.

Tower of Hercules (Wikipedia)

Monday, June 4, 2012

Greening Main Street Buildings

In the late 14th century, England's King Richard II commissioned a new building, College Hall(1), at Oxford University. The carpenters who built College Hall knew that the massive oak beams spanning the great hall's ceiling would probably need to be replaced in a few hundred years, so next to the building, they planted a row of oak seedlings from the trees they used for the beams. Sure enough, the beams needed to be replaced about 300 years later, and the new carpenters had mature oaks right there, ready to be milled and turned into new beams.

Among the typical environmentally friendly features of main street commercial buildings:

Shared party walls: Traditional main street storefront buildings are narrow and deep – 20 to30 feet wide by 100 to 150 feet deep – with shared side walls. For a 20-by-100-foot building on the interior of a block, 83 percent of the building's wall surface is shared with other buildings. The shared walls conserve heat, limiting the amount of wall surface experiencing significant heat loss to less than 20 percent.

Thick masonry walls: Solid masonry walls store heat and cooled air very efficiently, helping regulate the temperature inside the building.

Operable awnings: Awnings that can be rolled down when the weather is hot can reduce heat gain by more than 65 percent, and rolling up the awnings when it's cold outside increases heat gain inside the building.

Operable windows: Windows that open, as opposed to windows with fixed frames, help circulate air and regulate interior temperatures. For example, opening the top sash of a typical double-hung window on the sunny side of a room permits hot air near the ceiling to escape; opening the bottom sash of a double-hung window on the shady side of the room lets in cooler air.

Operable shutters: Just as awnings help regulate temperature gain through storefront windows, operable shutters on upper-floor windows keep rooms cool during hot weather by shading out the sun while still permitting ventilation.

Reflective ceilings: Shiny ceilings painted a light color, such as white or silver, reflect light back into the building, reducing or even eliminating the need for artificial lighting during the day.

Transom windows: Transom windows help magnify light shining into the building, providing more ground-floor ambient light while intensifying heat in the area immediately behind the storefront window.

Skylights: Like transom windows, skylights boost the amount of natural light in the building, thereby minimizing the need for artificial lighting.

Tall ceilings and ceiling fans: Hot air rises naturally. Tall ceilings in commercial buildings help keep the lower six feet or so of air space cool in warm weather, while ceiling fans circulate the air above, moderating temperatures in the store.

Passive solar: As sunlight shines through storefront and transom windows, the masonry flooring inside the storefront window absorbs heat, radiating it back into the ground-floor space when the temperature cools.

Water tanks: Roof-mounted water tanks collect rain water; and gravity, rather than a pump, delivers it to toilets and for other secondary uses inside the building.

Recessed entryways: Recessed entryways help prevent hot or cold air from rushing into the store when the front door is opened.

Atriums: Whether protected by a skylight window or open to the sky, an atrium illuminates the interiors of multi-floor buildings, lighting all the rooms and hallways facing it.

Embodied energy: The energy it took to manufacture the materials used in buildings, transport them to the construction site, and construct the building has already been spent and is embodied in the building itself.

Materials created locally: Historically, most main street building materials were purchased from local or regional sources, rather than being shipped in from long distances.

Walkability: Probably one of the most environmentally friendly characteristics of older and historic main streets is that they are walkable.

Durability: Unlike most of today's commercial buildings, whose lifespans are driven largely by taxable depreciation schedules, older main street buildings were built to last for decades, if not centuries, with durable materials like stone, brick, copper, and dense heartwood.

The list of the energy-saving characteristics of traditional main street commercial buildings could go on and on. But, unfortunately, the list of ways that property owners have mutilated main street buildings over the years, inadvertently eroding their green characteristics, is equally long. Among the more common energy-inefficient remuddlings:
  •     Enclosing upper-floor windows or replacing them with new ones. Some seem to think that replacing the upper-floor windows in a historic commercial building is an energy-wise improvement. The R-value of a double-glazed window, however, is only nominally better than that of a single-glazed window; and the historic window's heartwood frame will last decades longer than its replacement. It is usually more environmentally responsible, and less expensive, to simply repair the original window, seal any gaps or cracks around the molding to prevent air infiltration, and install an interior storm window.
  •     Installing suspended ceilings. Suspended acoustical tile ceilings erase several green characteristics of traditional main street commercial buildings – particularly in ground-floor storefront spaces. By lowering the ceiling height, they disrupt vertical air circulation. By blocking the transom window and covering up the bright, shiny original ceiling, they significantly cut the flow of natural light into the building.
  •     Enclosing storefront windows. Some businesses – especially professional offices and bars, it seems – have a tendency to reduce the size of their storefront windows by partially enclosing them. This disrupts the passive solar benefits of large storefront windows and, incidentally, disrupts the visual rhythm of the overall streetscape.
  •     Replacing functional awnings with fixed awnings. It seems as though awnings are now frequently used as business signs, rather than for the energy-conserving purposes – allowing or preventing heat gain – for which they were originally intended.
  •     Removing rooftop water tanks. Unfortunately, rooftop water tanks are only a distant memory on most main streets now; but, by collecting rainwater and using it to fill toilet tanks, they helped manage the district's storm water, reduced demand for treated water, and saved property owners money.

At its simplest level, making main street buildings more environmentally friendly involves just two things: using less energy and using fewer materials. Using less energy means consuming less energy, primarily through passive methods such as using natural sunlight and heat gain or generating more "green" energy, or both.

Here are some major actions that can make main street buildings greener:

Undo inappropriate alterations.

The first step in(re)greening main street buildings is simply to undo the alterations that have, over the years, reduced their energy- efficiency. In a few instances, the alterations may be so extensive that undoing them would be prohibitively costly. But, in most cases, the alterations are relatively simple, and it is usually possible to reverse them for a few thousand dollars or less: removing a suspended ceiling, for example, uncovering transom windows, or restoring a storefront window.

Seal air leaks.

Air leaks are one of the biggest energy-related problems in older commercial buildings. By most estimates, leaks around storefront and upper-floor windows through ducts and vents and around doors can waste 20 to 50 percent of the energy spent on heating and cooling commercial buildings.

Sealing air leaks in a main street commercial building is similar to sealing air leaks in a house. Make sure the weatherstripping around doors and windows is tight and that any cracks or gaps around doors and windows are caulked. Use duct insulation to wrap heating and cooling ducts. If the building has a basement or crawlspace,
be sure it is adequately insulated. If the building has a wood frame, make sure the external walls have adequate insulation in the cavities between the exterior siding and interior wall finish.

Certain types of blow-in insulation, such as rock wool, cellulose, and fiberglass, are environmentally friendly and can be installed without removing the interior sheetrock, plaster/lathe, or other interior wall finish. Be sure, however, that the insulation contractor checks the wiring in the walls first to make sure it can be encapsulated; some older types of wiring, such as "knob and tube" wiring can become a fire hazard if encapsulated with insulation.

Older masonry – stone, brick, concrete block, etc. – absorbs moisture from outside air and must be able to "breathe" to let moisture evaporate. Hire a contractor who has worked on older and historic buildings and understands how to install insulation and seal windows and doors in a manner that won't trap moisture inside walls or allow it to condense on wall or trim surfaces.

Repair or replace inefficient heating and cooling units.

According to the U.S. Department of Energy's Energy Efficiency and Renewable Energy (EERE) program, heating, ventilation, and air conditioning (HVAC) consume 40 to 60 percent of all energy used in commercial buildings and houses in the United States. According to the U.S. Environmental Protection Agency (EPA), cooling interior spaces alone accounts for 15 percent of all the electricity used in commercial buildings across the nation, second only to lighting. Of all the ways in which the energy efficiency of main street buildings can be improved, HVAC is without a doubt the most significant.

There is no single solution for all main street buildings. The best HVAC system for a particular building will depend on its size and materials, its orientation, the local climate, and the availability of nearby energy resources, among other factors. The good news is that more options for making main street buildings' HVAC systems energy- and cost-efficient are available now than at any point in history. Among some of the newer options:

High-efficiency, gas-fired rooftop units: By combining the condenser, compressor, and evaporator in a single unit and by using pulse combustion, these units control temperature better than older gas-fired rooftop HVAC units. Some newer units also modulate air flow, preventing the energy loss that results when an HVAC unit cycles on and off frequently.

Boilers: Many mid-size and larger commercial buildings employ boilers to heat interior spaces by using natural gas, oil, or coal to generate steam or hot water. New, energy-efficient boilers tend to be smaller, which enables a building owner to use several small boilers to heat different parts of the building to different temperatures, depending on building use. Also, boilers that use solar energy and biomass energy are now appearing on the market.

Generate on-site energy.

The range of options available for generating on-site electricity has expanded dramatically in the past few years. For older and historic main street buildings that have roofs with access to direct sunlight, roof-mounted photovoltaic solar panels that convert sunlight into electricity are becoming a practical option. Solar panels can provide part or all of the electricity required to operate a main street building, depending on how much sunlight the building receives and how much electricity it consumes.

Solar panels work through a chemical reaction triggered when sunlight hits a silicon wafer treated with phosphorus and boron. Each treated wafer is a solar cell; cells are joined together to form modules; and modules are connected to one another to form arrays. An array plus the other components needed to turn the solar energy into a usable form comprise a solar panel. Energy from a solar panel can be fed directly into a building's electrical panel for immediate use or can be stored in batteries for later use, or both.

During the early decades of solar energy use, wafers used crystalline silicon. Unfortunately, there is a finite supply of crystalline silicon in the world, it's relatively expensive, it's somewhat bulky, and it only passes along about 15 or 20 percent of the energy it harnesses. Today, several new advances offer solutions to these problems – using copper indium gallium selenide (CIGS, for short) instead of silicon, for example – and increased demand is gradually driving down prices.

Some historic preservationists worry that solar panels will spoil the appearance of a historic building. This is usually a greater concern with residential buildings than main street buildings; on a typical commercial building with a low parapet wall at the front roofline, the parapet may be tall enough to conceal the solar panels and thus minimize their impact on the design integrity of the building. For buildings with pitched roofs, solar shingles – thin-film solar panels that look like somewhat shiny asphalt shingles – might be the solution.

No other mechanism for generating on-site energy offers as much promise for main street buildings as solar energy – yet. Roof-mounted wind turbines can vibrate so much that they jar loose masonry and mortar, which makes them a poor choice for older and historic buildings. But researchers are constantly experimenting with new forms of energy generation, from harnessing the energy created when someone uses a revolving door to converting the heat absorbed by masonry surfaces into electricity.

Improve window efficiency.

For years, the windows of older and historic main street buildings have been closed in, punched out, and narrowed down by building owners who think that doing so will make the building more energy efficient. But, while it might be tempting to replace old windows with newer, double-glazed windows, window glass is not a major source of heat loss.

Studies by the Rocky Mountain Institute(4), the Vermont Energy Investment Corporation(5), and others have demonstrated that the energy savings that might be gained by replacing historic windows with new double-glazed windows is inconsequential. Glass, whether single-or double-pane, is a poor insulator. The environmental costs of manufacturing new windows and sending old ones to the landfill are far greater than the benefits to be gained in energy savings. Window efficiency can be improved, though. Be sure the weatherstripping on operable windows, usually those on upper floors, is tight and that any gaps or cracks around windows are securely caulked. Building owners can install interior storm windows, if desired, by attaching them to the interior window casing with magnets or brackets.

Obtain building materials locally.

A few years ago, contractors removed the stucco-like cladding that had covered a historic commercial building in downtown Dubuque, Iowa. Underneath, they found several cast-iron columns framing the storefront, all in good condition. Like most cast-iron columns made in the early 20th century, the name and location of the foundry where they were manufactured was stamped near the base: they had been made right there in Dubuque. At the time they were made, it was commonplace for building materials to come from manufacturers within the community or the region. Today, unfortunately, building materials are usually trucked in from many miles away. Buying materials locally or regionally cuts down on the amount of gasoline needed to transport materials and, ultimately, on costs.

Improve interior and exterior lighting. Compact fluorescent light bulbs have been commercially available for years now, and their cost and energy savings are well known. Other choices are on the horizon as well; LED light bulbs, in particular, could surpass compact fluorescents in light quality, bulb longevity, and cost efficiency. Until now, LED lighting has not been bright enough to replace traditional incandescent bulbs for interior lighting, but a few manufacturers are now producing LEDs powerful enough not only for interior use but also for streetlights.

There are many other things building owners can do to improve the energy efficiency of a main street building's lighting. Installing timers and occupancy sensors can ensure that lights are turned on only when needed. Removing the covering from a transom window and putting it back in use will dramatically boost interior lighting. Be sure the ceiling is painted a light color – better yet, with a glossy finish – to maximize natural light transmission.

Install green roofs.

Technologically, a green roof is pretty simple – it's basically just an engineered layer of vegetation on top of a building – but it helps the environment in two major ways: it improves air quality by absorbing carbon and releasing oxygen; and it absorbs rainwater, reducing runoff into the municipal storm water system. A typical green roof also has key benefits for the building. For instance, it helps prevent heat loss when it's cold outside, and it helps keep the building cool when the weather is hot, both of which lower utility costs. And, by protecting the roof surface from harsh sunlight, a green roof lasts longer than a conventional membrane or built-up roof, thereby reducing replacement costs.

There are two ways to install a green roof on a main street building: it can be integral to the roof structure itself, or it can consist simply of shallow planting boxes placed on top of the roof.

Green roofs that are integral to the roof structure can be extensive, which means that the growing medium is relatively shallow, that it is used primarily to insulate the building, and that the roof isn't usually employed as an outdoor room; or intensive, meaning that the growing medium is relatively thick, the roof can incorporate large plants, and the roof functions as an outdoor room. Green roofs that aren't integral to the roof structure but consist of planting boxes are generally referred to as roof gardens.

In either case, the rectangular, gently sloping roofs of most main street buildings are ideal candidates for "greening."

When a green roof is part of the roof structure, it includes an edge-to-edge membrane, similar to the rubbery membrane many main street commercial buildings already have, topped by a layer of rigid insulation; a planting tray; a growing medium, such as gravel, a shallow layer of soil or engineered soil, or a hybrid mixture; and a layer of vegetation. Sedum is the plant favored by most green roof engineers; rugged and durable, with a low profile, it absorbs an enormous amount of water. There are over a thousand varieties of sedum. Some work better than others in certain climates; but, for every climate, there are several varieties of sedum that will thrive.

Given that conventional membrane or built-up roofs have useful lives of only about 15 to 20 years, odds are that, every year, at least a few roofs in your district will need to be replaced. The cost of an integral, extensive green roof is only slightly greater than the cost of a conventional roof; so, within a few years, many of your district's buildings could be sporting new, green rooftops.

Greening Main Street Buildings

By Kennedy Smith | From Main Street Story of the Week | April 2009 | 260