Top 10 Green Advances in Commercial Building

Green building advances don't just focus on things like the building's structure or systems -- there are some lower-tech ways to "green" a building both inside and out. Hanging gardens (like, say, the legendary ones built by Nebuchadnezzar in Babylon) are nothing new, but usually they've been just pretty, not functional (or in the case of me and English ivy, just a sign of lazy landscaping). Here we're talking about a garden system that makes a building more environmentally friendly. When installed on the outside of a building, they can insulate it and reduce heating and cooling costs. Living walls -- also known as biowalls -- also reflect solar radiation, improve air quality by absorbing carbon dioxide and releasing oxygen, and absorb rainwater that would otherwise be runoff. They can also be watered with greywater (water that's been used for bathing, dishwashing or laundry).

Some companies have taken the living wall concept indoors. Obviously, they don't provide the same kinds of benefits indoors, but they can still purify the air and provide a way to recycle greywater. Looking pretty and improving your mood are added bonuses. A plant sitting on your desk can cheer you up -- imagine what looking at an entire wall of lush greenery could do? Both indoor and outdoor living walls are usually modular, made of removable panels with angled pockets to hold the soil. If they're indoors, special lights may need to be installed to meet the plants' requirements. The type of plant depends on where it'll be located and how much maintenance you want to devote to it.

Passive solar building design makes the sun an integral part of lighting, heating and cooling the building. The "passive" part of this type of design means that it doesn't require any sort of device, and unlike something like solar panels, it doesn't take a big initial investment or a long time to pay off. It's complicated, though; designers must carefully choose everything from the location, size, and type of windows and walls to the plants placed around the building for shade.

It starts with looking at the sun's path as its rays strike the building. Sure, you know that the sun rises in the East and sets in the West. It also "moves" across the sky during the day, and it's in a different position in the sky depending on the time of year. There are also a ton of other factors that go into the design, including insolation -- the amount of solar radiation absorbed by a surface area. That's not just influenced by the sun's rays, either; it also has to do with climate. Wind patterns, clouds, humidity -- they all make a difference in how hot or cold a building gets on the inside. Designers usually employ software to calculate the best placement and materials, and it's different for every building.

In general, a building using passive solar design has large windows and deciduous plants on the southern side (to let in maximum sunlight in the winter and shade in the summer). It also uses building materials that have high thermal mass -- meaning that they retain heat well -- like concrete and tile. Passive solar design cuts down on the energy used for the building's HVAC system as well as lighting. Having a commercial space lit by daylight is another mood-lifter, too.

Some commercial builders take water conservation a step further than the federally-mandated low-flow toilets and use water that's not safe for drinking, but is safe for things like landscape irrigation or flushing toilets. One way is a type of plumbing system designed specifically to conserve water, known as a dual plumbing or dual piping system.

This system separates water into two types: potable and reclaimed. Potable water is safe for drinking, cooking and washing. Reclaimed water was formerly waste or sewage. Sounds nasty, but the water is treated to remove any solid waste and cleaned to be free of harmful bacteria. You just wouldn't want to drink it. It makes sense that you don't need to use the same water to flush a toilet as you do to fill your glass, right? There are some disadvantages, though. It costs more to have two plumbing systems. Plus, not all cities are set up for reclaimed water use. In the United States, this system was pioneered in the Irvine Ranch Water District in California, which also set the standard of using purple piping to distinguish reclaimed from potable water.

A cheaper alternative is a system that uses greywater generated within the building itself. There are lots of different ways to go about it, too. It can require two different plumbing systems, include collecting rainwater to fill toilets or irrigate plants, or be as simple as installing special sink/toilet combinations in commercial buildings that allow the water from hand-washing to fill the toilet for flushing.

The LEED Green Interior and Construction Guide is hundreds of pages long, and there are similar long lists of requirements for green certification in other countries. There's a reason why the U.S. Green Building Council, for example, offers courses to become a LEED Accredited Professional. In short, there's a lot to know when it comes to green building, which is why some consultants, builders and designers specialize in it. And just like any other commercial construction project, there are lots of different people involved and invested in the process.

Companies have developed collaborative green design software to help make it easier to compare and contrast all of the different green building options available. One popular service, Sefaira Concept, has won a lot of awards -- including the 2011 Green Innovation of the Year at EcoBuild, a huge green design and construction event held in London. Sefaira is cloud-based, so everyone accesses it online instead of having to buy and load a program onto their computer. It allows designers to do things like set up and run scenarios showing the costs and benefits of using an energy source like wind turbines -- down to including details like the size of the blades on the turbine and how they'll be oriented. Or they can project water usage for the type and size of building and then look at how recycled water or graywater systems can best be used to reduce the amount of necessary potable water. Sefaira's software and other types of green design software help commercial buildings live up to their full potential when it comes to going green.

HVAC (Heating, Ventilation and Air Conditioning) systems are also known as comfort systems -- while some people are willing to wear a sweater or use a fan indoors, most aren't game to really sweat it out in the summer or freeze in the winter in the name of saving energy. There's no shame in that, but HVAC systems use more energy than anything else in a commercial building. Air conditioning also results in tons of carbon dioxide emissions, so making HVAC systems as green as possible is a huge concern. There are plenty of ways to minimize how much they're used (like passive solar design or improved insulation), but there's no way to ditch them entirely.

While some traditional HVAC systems are more efficient than others, there are also alternatives like a chiller boiler system. Typical HVAC systems use forced air to heat and cool, but a chiller boiler system is hydronic -- meaning that it uses water -- which is more efficient because it provides even temperatures. These systems are attached to the water supply in the building. If this sounds familiar, you may be thinking of radiators, an older hydronic system that uses steam to heat. A chiller boiler warms you up using radiant heat instead of hot water. It's sort of like the heat you feel if you hold your hand near a flame -- it's not actively blowing hot air on you but giving off heat that warms the room from water-filled copper and aluminum pipes. Putting in a chiller boiler isn't really cost-efficient for a really large commercial building, but they can work well in smaller ones.

When I think of building insulation, I think of pink, itchy fiberglass. But I also know that fiberglass isn't exactly a green option -- it releases irritating, potentially harmful fumes and can contain formaldehyde. A building has to be properly insulated to be energy-efficient, so what's a green-minded company to do? Luckily, lots of options are on the market, including insulation made of other materials. One company makes rolls of insulation that look similar to the pink stuff, except it's blue -- because it's made out of old denim! It's hard to imagine your favorite pair of jeans potentially filling the walls of a new building, but it's possible. No fumes, no itchiness if you touch it and it's treated to be fire retardant. There's also insulation made from recycled plastic milk bottles or newspapers. As with denim insulation, both materials are treated to be fire retardant.

If just recycling another fabricated material isn't innovative enough, how about something made directly from plants? Some manufacturers are producing structural insulated panels (SIP), a prefab panel that can contain straw previously used in agriculture. Hemp and flax are also seeing more use in European countries like the Netherlands and the United Kingdom as an alternative insulation. It doesn't need any kind of chemical treatment, and it's a fast-growing plant.

If you delve into the world of window shopping-- and I'm not talking abou the phenomenon of looking without buying -- lots of companies make promises about energy efficiency. Most of these are focused on insulating through multiple panes or glazes, or on their ability to let in lots of sunlight in the winter to maximize solar heating. Electrochromic glass (also called smart glass), however, uses electricity to change the glass from opaque to translucent. It can happen with the push of a button, or it can be programmed to change over the course of a day as the sun moves, using a centralized system.

Electrochromic glass uses nanotechnology, with layers of ceramic plates between glass that are thinner than a hair. These ceramic plates are coated with materials like tungsten oxide, which change from clear to dark with a quick, low-voltage burst of electricity. Reversing the charge changes it back. Not only does electrochromic glass save energy by reducing the load on an HVAC system, but it can also provide lighting in the form of skylights and can eliminate the need for shades or other window coverings.

If I spot solar panels on a building, I immediately think that the occupants care about the environment. It's even more impressive on a commercial building because it takes extra money and effort to make it happen (just as with many green advances). But not all solar panels are built equally. The earliest ones weren't incredibly efficient and didn't actually generate that much usable energy. The latest in solar panel technology is called photovoltaics, and they've come much further than just a few panels on the roof. How impressive would it be to see an entire building covered in panels that harnessed the power of the sun? The thing is, you might never know it's happening.

Traditional solar panels stand out from the rest of the building and sit on top of the regular roof structure. Photovoltaic (PV) panels actually replace traditional structures, making them more cost-efficient from the start. They can even be semi-transparent, replacing windows and skylights. The term "photovoltaic" means that electric current is immediately generated in the panels when they're exposed to sunlight. These panels can theoretically create a closed grid -- a building that can generate and use its own electricity. Most of the buildings using PV panels now (such as the CIS Tower in England) feed the power they generate to the national power grid because a stand-alone system requires a way to store the power (such as batteries).

DC -- as in direct current? You bet. Today we use AC (alternating current) power developed by Nikola Tesla, but back in the late 1880s, Thomas Edison's DC was king. The problem was that it couldn't travel very far without a loss of power, and AC, with its higher voltage, could.

So why are green builders looking at DC today? Using AC always results in a loss of energy, both because of the inversion needed for the various voltages of electronics and appliances in our homes and because most of those electronics use DC. Computers are a prime example. If you feel that big "brick" on your power cord after using your computer for a long time, it's hot. That heat is energy, lost during the inversion of AC to DC.

Until we started looking at alternate sources of energy, there wasn't much to do about the energy loss -- AC was still more efficient overall and that's how our power grid was designed. However, the use of solar panels has changed things. They generate DC, which is usually fed back into the power grid ... which uses AC. You see where this is going. If you have a way to use DC power directly in your building, however, you could take the energy you're generating via solar panels (or wind turbines, or whatever you want) and use that to power electronics that already use DC without the energy loss. Currently, there are "microgrids" available that work with existing AC systems and supply energy to power things like compact fluorescent lighting panels, but many green construction experts are predicting a return to DC in the future.

Let's get back to nature with our final item on the list. We've talked about living walls, modular panels inside and outside of commercial buildings that contain live plants. We also touched on using plant materials like hemp and straw for insulation. But what if the very walls themselves were made of plant material? More than one journalist has compared mycoform technology to the Smurfs' mushroom houses and with good reason. This tech involves actually growing building materials using mycelium, a type of fungal spore.

Researchers have found that they could fill a form, such as a large block, with an agricultural product that would otherwise be waste material, such as buckwheat husks. The mycelium feed off the husks, growing to fill up the empty space in the form, and then it's heat-treated to kill the spore and stop its growth. The result is a strong, solid brick or plate of "mushroom" material, in whatever shape you want. They're inexpensive and require no toxic chemicals or a lot of energy to make. The downside is that they're also totally biodegradable, but if the molds for the bricks are made out of recycled aluminum, or the material is used as insulation between other non-biodegradable materials, you can avoid it breaking down. Unlike the other items on our list, this one is still in the experimental stages (although it's currently being used for packaging), but who knows what the future holds in green construction?