In the past, cogeneration was implemented only by utilities and certain very large energy users such as hospitals, plants and prisons. But recent improvements in technology and reductions in the size and cost of equipment have made it practical for a much wider range of buildings and applications.

On-site cogeneration is extremely efficient, since heat is not lost in transmission. Because so little fuel is wasted, cogeneration is one of the most cost effective methods of reducing the carbon emissions associated with heating in cold climates. And the steam energy can also be used for air-conditioning and refrigeration.

Con Edison has been using large-scale cogeneration plants for a number of years to provide steam to buildings in Manhattan. The fuel efficiency of cogeneration plants is normally over 80% because they capture and distribute excess heat, even after allowing for the loss of energy involved in transporting heat over fairly long distances. That is a major improvement over the performance of conventional electrical plants, in which 60% of the energy generated literally goes up in smoke and about 10% of what’s left is lost during transmission.

Most buildings in cities like New York are occupied not by a single owner, but by multiple tenants, shareholders, or unit owners (for the sake of simplicity we’ll call them all “tenants” from now on) and the cost of electricity is usually allocated based upon the amount of space each tenant occupies, rather than by usage. So a tenant who invests in every energy saving measure available pays the same amount as one who leaves all of the lights, air conditioning and equipment on 24/7. When there is no direct correlation between what you use and what you pay, you tend to use more power.

Submetering makes it possible for buildings that have one master electric meter to charge individual tenants for the power they use. It works well for both commercial and residential buildings.

In the past the cost of installing a new meter for every tenant space and providing the staff necessary for monthly readings was a barrier to widespread acceptance of submetering. However, advances in meter technology and an increase in the financial incentives provided by entities such as the New York State Energy Research and Development Authority (NYSERDA) have made submetering more attractive. The cost of the metering systems has dropped, and it is possible to install meters that can transmit monthly readings over existing electrical wiring -- or via wireless communications -- to a remote billing location, eliminating the need to rewire the building to allow for remote meter reading. Submetering can be installed one space at a time, so a building can offer this option on new leases without affecting existing ones.

The advantage of using a master meter and submetering, rather than having each premise individually metered by the electric company, is that buildings with master metering are entitled to a bulk-rate discount and pay significantly lower rates for their electrical power.

There are a number of LEED rating systems, but the ones that most people are likely to encounter are New Construction, Existing Buildings, and Commercial Interiors. The system that I believe has the widest application is Commercial Interiors, the standard used for design and construction of tenant spaces within existing buildings.

LEED sustainable design and construction guidelines are divided into the following categories:

• Sustainable Sites

• Water Efficiency

• Energy & Atmosphere

• Materials & Resources

• Indoor Environmental Quality

• Innovation & Design Process

Site Selection

If you plan to undertake a LEED for Commercial Interiors project, the surest way to comply with (and get points for meeting) guidelines for Site Selection and to facilitate compliance in other categories is to locate your project in a building that is LEED Certified. If there are no such locations available that fit your needs and your budget, you can still get points for Site Selection if the building in which you locate your project has certain sustainable characteristics. A brief explanation of some of the more common characteristics of green buildings follows.

A site that manages rainwater well minimizes water pollution by reducing the amount and speed of water that goes into gutters and sewers, and from there into streams, lakes, rivers and oceans, during storms. Plants on the roof or surrounding the building absorb rainwater and slow it down. Permeable pavement (like gravel or brick) is preferable to impervious pavement (like asphalt or concrete). Some buildings collect rainwater and use it on site, and some use extractors or constructed wetlands to remove pollutants. (Stormwater Management: Rate and Quantity and Stormwater Management: Treatment)

Streets, sidewalks, parking lots, and buildings all contribute to making developed areas hotter than rural areas. Shade, vegetation and light colored, reflective surfaces surrounding buildings and on their roofs as well as underground parking all help to keep things cooler. Building practices that minimize outdoor heat can save electricity and money by reducing air conditioning loads. (Heat Island Reduction: Non-Roof and Heat Island Reduction: Roof)

Lighting should be designed to eliminate glare, discomfort and annoyance for neighbors, avoid disruption of nocturnal habitats and preserve visual access to the night sky. Light levels on a site should not be higher than necessary, and fixtures should be shielded to contain light within a site’s property boundaries. (Light Pollution Reduction)

Clean drinking water is becoming increasingly scarce on this planet, so Sustainable Sites limit the use of potable water. To reduce the amount of potable water used for irrigation they use indigenous plants, use rainwater and/or recycled site water instead of drinking water, and use highly efficient (or better still, no) irrigation systems. Sustainable Sites limit the use of potable water for toilets, sinks and showers by using highly efficient fixtures and sometimes reuse site water to flush toilets. (Water Efficient Irrigation and Innovative Wastewater Technologies)

Developmental Density and Community Connectivity

Sites in established communities in which you can walk to both a residential area and a number of basic services are intrinsically sustainable.

Alternative Transportation

Transportation accounts for a large percentage of energy use in the United States. Sustainable Sites have convenient access to public transportation and/or encourage car pooling and bicycle riding.

Sustainable interior design, architecture and construction save water by using dual-flush or low-flow toilets, low-flow or waterless urinals, faucets that work on sensors, low-flow showerheads, and front-loading washers. Sustainable design techniques also sometimes include reusing waste water from sinks for flushing toilets and for irrigation. Sustainable landscape design uses native plants to minimize the need for irrigation (as well as herbicides and pesticides), highly efficient irrigation techniques, and rainwater or recycled site water.

The LEED rating system recognizes Energy and Atmosphere by having more prerequisites in this area than in any other. While meeting the first prerequisite is within the control of the project team, meeting the other two is closely related to characteristics of the base building, and should be considered during site selection.

1. A commissioning agent (normally a LEED AP engineer) not directly involved in the design or implementation of the project must verify that all energy- related systems are installed, calibrated and perform as intended. (Fundamental Commissioning)

2. The systems must meet minimum energy requirements compared to ANSI/ASHRAE/IESNA 90.1 or local code, whichever is stricter. (Minimum Energy Requirements)

3.HVAC and refrigeration equipment installed within the scope of the project cannot use any CFC-based refrigerants. (CFC Reduction in HVAC&R Equipment)

One way in which sustainable buildings save a lot of energy is through the design of their lighting systems. Choice and placement of lighting fixtures, control systems, and use of daylight all play a role. (Optimize Energy Performance, Lighting Power and Optimize Energy Performance, Lighting Controls)

Another major way to save energy is through the design and operation of the systems that provide heating, cooling and ventilation. (Optimize Energy Performance, HVAC) While replacing HVAC equipment is often not within the scope of a renovation project, adding zoning and controls and involving building occupants, maintenance staff and cleaning crews in energy saving initiatives can all make a big difference.

The third way to save energy is by using the most efficient equipment and appliances possible and by turning everything off when not in use. All new equipment should, at a minimum, have an Energy Star label. Most equipment uses some power even when it is not in use, so plugging it into a power strip that is turned off every evening is preferable to plugging it directly into a wall outlet. (Optimize Energy Performance, Equipment & Appliances)

Enhanced Commissioning is similar to Basic Commissioning, except that the commissioning agent cannot be an employee of any firm they is directly involved in the design or execution of the project.

While just about everyone is in saving energy, not too many are willing to pay a premium to do so unless there is a positive return on investment. So it’s important that the party who is paying for improvements to a space get the benefit of any cost savings associated with saving energy. This can be easily accomplished by sub-metering the space or, in the case of larger premises, having the tenant paying the utility directly, but it is very important to have an understanding between landlord and tenant in the lease. (Energy Use, Measurement & Payment Accountability)

Recycling materials that can be reused is so important that the U.S. Green Building Council has made storage and collection of recyclables, including paper, corrugated cardboard, glass, plastic and metals a prerequisite in order for a building or an interior project to achieve LEED Certification. (Storage and Collection of Recyclables)

In many cases, the greenest thing that you can do is to avoid or limit construction. LEED recognizes this by encouraging people to find space that will serve their needs for an long time (Tenant Space, Long Term Commitment) and that needs relatively little reconfiguration (Building Reuse). LEED also encourages limiting the materials that wind up in landfill by salvaging or recycling construction, demolition and packaging debris. (Construction Waste Management)

LEED encourages the reuse of building materials from the original building (for example, refurbishing and reusing existing hardware) or other buildings (for example, using paneling or beams from a resource specializing in architectural salvage). (Resouce Reuse). LEED also encourages reusing furniture that you already own and / or purchasing used furniture. (Resource Reuse, Furniture and Furnishings).

Recycling only works if the materials saved are then used. It has become relatively easy to find high-quality attractive construction materials and furnishings with high recycled content (Recycled Content – Post-consumer + ½ Pre-consumer).

The further things travel, the more energy is used for transportation, so a project can earn LEED credit by using materials and furnishings that are manufactured locally (Regional Materials), or better still, manufactured locally from materials extracted locally (Regional Materials, Extracted and Manufactured Regionally).

Trees take a long time to grow, whereas bamboo can grow a foot a day and cork (which is the bark of cork trees) can be harvested every year without damaging the trees, and wheat not only matures quickly, the material used in buildings can be a by-product of producing food. (Rapidly Renewable Materials)

High performance buildings are relatively air-tight. Since there is little or no outside air entering such buildings except by conscious design, it is extremely important to make sure that the ventilation system is working properly. If there is not enough fresh air from outside passing through a building, the occupants can develop sick building syndrome or building related illness. So a building that does not meet minimum requirements as defined by ASHRAE 62.1 will not be able to achieve LEED certification. (Minimum IAQ Performance)

For a building to achieve LEED certification, smoking must either be prohibited throughout the building or the spaces in which smoking is permitted must be isolated so that smoke cannot migrate to other areas either naturally or through the heating, ventilation and air conditioning (HVAC) system. (Environmental Tobacco Smoke Control)

A plentiful supply of fresh air can improve occupant comfort and health. (Increased Ventilation) Installing sensors and measuring devices helps ensure adequate ventilation while maintaining energy efficiency. (Outdoor Air-Delivery Monitoring)

Construction management procedures can have a major impact on indoor air quality. All HVAC equipment should be protected from dust and odors and all ducts should be sealed during construction. Work areas should be isolated from the rest of the building and job sites should be kept clean. Porous building materials should be protected from moisture and stored in a clean area. New, highly efficient filters should be installed in HVAC equipment immediately prior to occupancy. (Construction IAQ Management Plan – During Construction)

Even with the best construction management procedures, a certain amount of dust and toxins are often introduced into a newly-built or renovated space. Air quality can be improved by performing a “flush out” procedure in which the building's ventilation system is used to eliminate contaminants and then air filters are changed again before occupancy. If the air in a newly-constructed or renovated space can pass certain tests for indoor air quality, a “flush out” may not be necessary. (Construction IAQ Management – Before Occupancy)

Most people are aware that the paint that we have been using for many years contains Volatile Organic Compounds (VOCs) that are potentially irritating or harmful to our health. LEED criteria include limiting emissions of both VOCs and formaldehyde from a wide variety of sources. A project can earn points by meeting standards for:

Low Emitting Materials – Adhesives and Sealants

Low Emitting Materials – Paints and Coatings

Low Emitting Materials – Carpet Systems

Low Emitting Materials – Composite Wood and Laminate Adhesives

Low Emitting Materials – Systems Furniture and Seating

LEED encourages isolating sources of potentially hazardous materials, including those from copying, printing, housekeeping and laundry rooms. LEED guidelines include construction techniques for isolating areas that house these materials. (Indoor Chemical and Pollutant Source Control) Using only green cleaning products can eliminate the need to isolate housekeeping areas

Most people feel more comfortable if they can control the amount and position of light in their workspaces, so LEED encourages providing individuals with the ability to adjust lighting for their task needs and preferences. Giving individuals control of their lighting can also save energy and money, since most people are comfortable using less overhead light (which often produces glare on computer screens) and using task lighting only for reading paper. (Controllability of Systems – Lighting)

In the typical office building, the operations and maintenance staff regularly deal with complaints from some people who are too hot and others who are too cold. LEED encourages giving control of the temperature and ventilation of individual spaces to the person(s) who occupy them. (Controllability of Systems – Temperature and Ventilation)

Relatively few projects (and very few renovations in existing buildings) will include the installation of systems to allow individual control of temperature and ventilation, because such systems often have relatively long pay-back periods. But every project can and should result in indoor temperatures that are comfortable for most people. (Thermal Comfort – Compliance)

Designing and building a system to provide comfortable indoor temperatures and adequate ventilation year-round while optimizing energy efficiency is difficult. Such systems often need to be monitored and adjusted both shortly after installation and on an ongoing basis. Monitoring can involve either the use of systems that automatically measure temperature and humidity and/or surveys of occupants. (Thermal Comfort – Monitoring)

1. Trees are not a rapidly renewable resource.

2. While fireplaces have been used as a source of heat for centuries, using one in a modern, air-tight home can result in poor indoor air quality.

3. Most fireplaces actually drain heat from a home, both while they are burning and when they are not being used.

4. Burning wood does generate CO2

I personally love fireplaces, and delight in a crackling fire on a cold winter day. But their value lies in their beauty and their emotional impact. They are not a sustainable source of heat.

The article also suggested using a geothermal system for heating and cooling. Geothermal systems can save a lot of energy, but won't work properly unless the ground is suitable. So you should get expert advice and a soil test before deciding to use this technology.

1. The greenest thing that anyone can do is to reuse things rather than replace them. I suggest that the Obamas take full advantage of the existing stock of wonderful furniture that the White House already owns, as well as incorporate pieces from their home in Chicago. They also might want to examine the White House inventory to see if there are any lovely old rugs that can be reused.

2. For new purchases, the Obamas should select things that will give them many years of pleasurable use. To be sustainable, furniture should stand the test of time, both stylistically and physically. If the Obamas need to compromise in order to stay within budget, the last thing that they should economize on would be the durability and comfort of the sofa(s) in the family room.

3. Generally, it’s best to keep things natural. Natural dyes are preferable to metallic dyes, and it’s even better to avoid dyes altogether.

4. All men may be created equal, but not all materials are. How something is produced is very important. For instance, most cotton is grown using toxic pesticides, so the Obamas would be better off using cotton that has been organically grown.

5. For the bedrooms, where good air quality is essential, I recommend carpet made of 100% wool that has been manufactured without using harsh chemicals, mothproofing, or stain repellent. The padding should also be a natural material, such as wool or sanitized hair and jute.

6. Any liquids – paints, adhesives, cleaning products, etc. should contain as few Volatile Organic Compounds (VOCs) as possible, and furniture should not have any added urea- formaldehyde. Toxins should also be avoided in maintaining the lawn and gardens, especially when there is a puppy who will want to roll in the grass and snuggle the children..

7. Window treatments should not cover too much of the glass, since maximizing daylight will save energy and make the Obamas and their guest most comfortable. The window treatments in the public rooms of the White House, with their short valances and pulled back draperies, are a good example of how this can be achieved in a traditional interior.

8. Energy efficient lighting should be used throughout the White House. Display cases in the China Room and elsewhere could be lit by LEDs. The incandescent candelabra bulbs used in chandeliers and sconces should each use no more than 45 watts, and the fixtures should all be on dimmers. CFLs should be used in lamps and fixtures that have shades, and all fluorescent bulbs should be properly recycled.

9. I recommend that the entire building be retro-commissioned in order to determine whether systems are operating as they should.

• Zero or low “VOC” paints, wall coverings, stains, adhesives and sealers should be used instead of materials that emit unhealthy substances unless the lower “VOC” product is really not strong or durable enough to do the job well. .

• Wood and bamboo products should have no added urea formaldehyde.

• Carpet, carpet pads and furnishings can also emit toxins. In general, organic and untreated fibers and water-based finishes are preferable.

• Manufacturer’s Data Sheets should be read to ensure that products live up to marketing promises.

• Products that have been certified by one of the following have proven sustainable qualities: .

Green Seal (www.greenseal.org) .

GREENGUARD (www.greenguard.org) .

SCS (www.scscertified.com).

• Air conditioning vents and equipment should be covered properly during the entire project.

• Possessions should be removed from the site if possible. Anything left on the premises should be covered and placed in a separate, sealed off space.

• Whenever possible, windows should be left open while work is being done. Window fans can help to exhaust dust and fumes.

• The filters in all air conditioners should be changed when construction has been completed and before occupancy. It is best to use the highest rated filters that will fit the units.

REGREEN is a set of guidelines for sustainable home remodeling projects. Jointly developed by USGBC and ASID, REGREEN addresses a wide variety of residential remodeling projects, from renovating a single room to major additions or modifications to an existing home interior. The guidelines provide a series of green strategies and case studies and address product selection as well as methodologies for sustainable home construction.

A home cannot achieve LEED Certification through REGREEN because it is a set of guidelines, not a standard. LEED for Homes is still the applicable standard for low-rise residential design and construction, and addresses new construction and gut rehabs. REGREEN provides sustainable design guidelines for residential remodeling projects on existing homes.

The Green Home Guide website of USGBC has a great deal of information on sustainable residential design: