Green Building

Green building has become a popular topic in recent years. So exactly what is it, and why is it important?

We’re used to thinking of energy consumption as related to the cars we drive and other transportation. But 40% of the energy consumed in the United States is used by buildings. So there is a large impact to be made if we can reduce energy usage in our homes and workplaces.

What Is Green Building? And What Isn't It?

  • Energy conservation, which creates lower ongoing costs to operate a home or business, more comfort for the inhabitants, and a more limited temperature swing over the course of a day.
  • Resource conservation, which improves the health of the planet.
  • Improvements to indoor air quality, which improve human health.
  • Refers to a green process, not just a green product.
  • Includes trends in home downsizing and the tiny building movement.
  • Relies upon durability, timeless design, and time-tested design and materials.
  • Is not "green washing".
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What is "Green Washing"?

Green washing is basically an attempt by a company to present their product or service as green. In reality it is an effort to sell someone more products or services that aren’t green at all. It results in consumers buying things they don’t need, and to over- or mis-consumption.

Remember that having more stuff will not necessarily make you happier. More stuff might make you happier if those things improve the quality of your life, reduce your costs, create less environmental impact, or create more time for you. How do you know if you’ve got too much stuff? A rule of thumb is that if you’ve got to rent space to store all your stuff, you probably have too much stuff!

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14 Things You Can Do to Make Your Home Greener

  1. Reduce, reuse, and recycle construction materials.
  2. Replace incandescent bulbs with compact fluorescent or LED lighting.
  3. Get a home energy audit by a reputable company.
  4. Insulate the attic of your home in the roof plane.
  5. Seal all points in the house that can leak air, including windows, doors, and fireplaces.
  6. Seal ducts well with mastic, not just tape.
  7. Install a heat recovery ventilator.
  8. Install radiant barrier roof sheathing.
  9. Install light-colored roofing to reflect heat away from the attic.
  10. Use low VOC paint when painting the interior.
  11. Install hard surface floors such as bamboo, linoleum, cork, or concrete instead of carpeting.
  12. Install energy-efficient appliances, such as refrigerators, dishwashers, washers, dryers, and hot water heaters.
  13. Install water-efficient toilets
  14. Install on-demand water recirculation in conjunction with a tankless water heater, so that water isn’t wasted while it is warming up. These recirculation systems utilize a motion sensor to turn on, take 15-20 seconds to bring the temperature up, can be retrofitted into an existing system, and cost about $800-$1000. They do require an electrical outlet.
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Ways to Improve Indoor Air Quality

  • Use a low VOC interior paint. Benjamin Moore Aura is one good brand. Use regular paint for outdoor applications.
  • Replace carpets with hard surface floors (wood, cork, integral color concrete)
  • Reduce carpeting. The weight of carpeting increases 5-fold over its life due to absorbed dust, debris, moisture, pets, grime, grease, etc.
  • Install heat recovery ventilation or exhaust fans. You must seal the house first: the attic, crawlspace, chimney flue, flues for the hot water heater, furnace, etc. to prevent the intrusion of dirty air.
  • Open gas cook tops in kitchens are a big source of indoor air pollution. Unburned gas, combustion products, and contaminants in natural gas enter your home this way. These types of cook tops cause 60% of indoor air pollution! Use a hood, or get a magnetic induction cook top instead.
  • Vacuum out debris from the attic and crawlspace to reduce toxic materials, particulates, and dust in your home.
  • Reduce particulates by using a pleated air filter in your HVAC system.
  • Install and use a central vacuum system to exhaust dust to the outside.
  • Vent all combustion gases (range, furnace, and hot water heaters).
  • Use non-formaldehyde wood products and insulation (e.g. no melamine).
  • Reduce moisture levels in your home to reduce mold growth by installing vapor barriers under your house, or dehumidifiers inside or underneath your house. Abate any existing mold by stopping the source of water intrusion and using a qualified contractor to remove and replace infected sheetrock, insulation, and wood.
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Resource Conservation

  • Recycle as much of the house and construction materials as possible during a remodel, because less transportation is needed, thereby providing an energy savings. In addition, less landfill waste is produced.
  • Use natural materials whenever possible.
  • Instead of paint, use integral color in stucco siding.
  • To minimize construction dust and job site dust, seal off the work area and filter the air while working. Vacuum out all dust before closing up walls.
  • Reuse materials on-site.
  • Using local materials if you can is very important. Cork and bamboo are not local!
  • Go to Craigslist to recycle materials, or to find recycled materials to use. Examples are gravel, concrete, wood, etc. Other sources of recycled building materials are listed at the bottom of this page.
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Energy Conservation

  • What is the real cost of energy? Are the true costs included in the price you pay? Consider the cost of wars and the military, that fact that oil depletion is occurring and that there are other uses for petroleum like plastics and pharmaceuticals, as well as the environmental costs (e.g. pollution due to oil spills, global warming, tar sands such as those in Alberta, Canada).

    Implementing a carbon tax could capture the true costs. If all of the true costs of energy were to be factored in, its actual price would be much higher, and our consumption would decrease dramatically.

  • On its way from the power plant to your home or workplace, two thirds of electrical power transmitted is lost as heat due to resistance. If electricity is generated close to the point that it is consumed, it is like having 3 times more power! Since photovoltaic panels generate power at location of usage, they have this built in advantage over power generated remotely at a power plant. One aspect of smart electrical grids is that they allow the use of electricity generated close to source first.
  • Replace light bulbs with compact fluorescent (CFL) or light-emitting diode (LED) types to reduce your power consumption by at least 4-fold.
  • Do photovoltaic (PV) panels make sense for your home or workplace? They have a payback period of 7-15 years. The price of installation is actually cut in half by available subsidies. For businesses there is a 30% tax credit, State of California rebates of 20%, and a federal tax credit of 30% on the whole cost.

    Assuming a 5% per year increase in energy prices, the payback period is 7-8 years. Without the 5% escalator, there is a $400 per month savings or $5000 per year, and the payback period is 12 years.

    Remember that electricity cost for usage above baseline amounts is priced much higher, so the savings are greater. In other words, if you are using more than $400 of electricity per month, you are paying $0.35 per kWh, so it helps even if you don’t have enough production capacity to cover all of your actual electric usage.

    Installing PV is a "no-brainer" for commercial use, because the peak usage of a business is during day, which is precisely when you generate the most electrical power with PV panels, and you are using that power at its point of production.

  • Install low-emittance (low E) glass to keep unwanted heat out and wanted heat in. Installing double pane glass will produce even more energy savings, and make the inside of your home or workplace quieter. Installing windows with these features can save 20% on your energy bill. Window replacement is not at top of the list for energy savings due to their relatively high cost. Avoid metal frames, and instead use windows with wood, vinyl, aluminum-clad wood, or fiberglass frames. Wood frames are the best from a low-heat-transfer standpoint.
  • To conduct performance testing, air is pushed air through the house, and the total amount of air leakage is calculated from the amount of the measured pressure drop. Air leak locations are identified with "fake smoke". A typical home performance evaluation costs about $700. During the evaluation they will also check electrical usage, air exchange, and the balance air with calculations and measurements.

    Homeowners can get energy readouts for their home from the PG&E website, as well as the cost of electricity. Actual usage for your home can be determined from past PG&E bills. By looking at your summer gas bill, you can determine the water heating demand for your home.

  • Run ducts through conditioned space to improve efficiency and air quality. Since ducts are typically run in the attic or crawlspace of a house, this means that these areas need to be conditioned. Typical ducts leak about 30% of the heated or cooled air running through them, but this number should be <6% for good efficiency and air quality.

    Reducing leakage from ducts improves air quality because leaks in the ducts cause the entrainment of large amounts of unconditioned, unclean air from interstitial spaces in the attic and crawlspace that contain dust, particulates, and mold spores. Effective duct sealing requires the use of mastic, not just duct or foil tape. Debris in attics should be vacuumed out, and the ground underneath the house needs to be sealed with a barrier at least 10 mil thick.

  • Add attic insulation and weather stripping to improve your home’s energy efficiency. Keep in mind that even a ¼" gap in insulation allows heat to escape! Studies show that with even a ½" gap, half of the insulating value is lost. The best type of insulation to use is open-cell spray foam, or well-fitted fiberglass bats. Blown in insulation settles over time, and the gaps created greatly reduce its effectiveness.

    When insulating in the roof plane, open-cell spray foam or fiberglass bats are best. Both of these are permeable to water, so that any roof leaks are obvious, and they can be removed and replaced if damaged by water. The ideal insulation is sticky or adhesive, is non-petroleum based, has a 200-year life, and is rigid with no gaps.

    Insulating in the roof plane turns the attic into conditioned space through which ducts can be run. Not only is it cheaper than insulating in the ceiling joists, but it is safer, as you will not be placing insulation around wiring. Insulation in the roof plane can cut your energy bill by 20%, saving you at least $120/year.

    In the crawl space, seal the ground with a vapor barrier on the soil that is at least 10 mil thick and is fiber reinforced. You may need to change out the vent screens with a louvered type in order to keep outside water from rain or irrigation systems from entering the crawl space, and to prevent wind from directly blowing through the crawl space and carrying away heat.

  • Install a "cool" roof to reflect heat back and keep your attic and home cool in the summer. Because high heat also dramatically shortens the life of a roof, cool roofs last much longer as well. These roofs can simply be a lighter-colored traditional roofing material, or one of the new spray-on materials developed at Lawrence Berkeley Labs.

    The spray-on material is very long-lasting, but is intended only for flat or shallow-pitched roofs. The original bright white color is effective but ugly, quite frankly. A new line of "cool colors" that are easier on the eye have been developed and are also available. When making your decision, consider not only their appearance to you, but to your neighbors as well, and you will maintain their happiness and property values as well as yours!

  • When choosing a hot water heater, consider condensing storage water heaters and power-vent water heaters. Like a high efficiency furnace, these water heaters condense water from the flue gas to recover the maximum amount of energy possible. The power-vent type provides cool exhaust which can be run through common PVC pipe over a long, non-linear run, and is a good choice for retrofitting older homes.
  • To save money on hot water, install an on-demand recirculation pump, also known as a Metland pump, in conjunction with on-demand (tankless) water heater. The pump recirculates cold water from the hot water line into the cold water line. A motion sensor detects when you walk into room and turns on the pump until hot water is available at the tap. By insulating the hot water line, energy loss is minimized.
  • How do ground source heat pumps compare to photovoltaic panels in terms of energy savings relative to the cost of installation? Both systems cost a similar amount to install, but the ground source heat pump will save 10 times more energy than the PV panels over the lifetime of the hardware.

    Ground source heat pumps do need electricity to run their compressor, but much of this can be provided by PV panels. Ground source heat pumps are most beneficial in climates with a large difference in temperatures between the outside air and the constant ground temperature. They also require access to the ground to dig down or laterally for the installation of the heat exchange coil, and so can be difficult to retrofit in confined areas.

  • When choosing a cooling system, adapt to your location. Evaporative coolers, also known as swamp coolers, work well in dry areas, such as the valleys lying outside the Bay Area, where it is hot but dry.
  • When choosing a heating system, consider a hydronic air handler, which combines a hot water heater with a furnace in one appliance.
  • Consider the installation of a heat recovery ventilation system to bring in fresh air, but keep the warm or cool temperature inside. Installation requires that the air leaks in a home are sealed first. A counter-current exchanger brings in fresh air, but exchanges heat so that the inside of your home or workplace remains cool in the summer and warm in the winter. Simple exhaust fans also work for this purpose, but do not exchange heat.
  • What will the next generation of buildings be like? In the 1970s, passive houses were designed that used plenty of insulation, but these houses overheated and had bad indoor air quality. With the inclusion of a heat recovery ventilator, waste heat from human bodies, appliances, computers, and lights can be captured. Adding photovoltaic panels to such a house creates what is known in Germany as an Active house, and is the ultimate in both energy conservation and a healthy indoor air environment.
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Resources

New Avenue Homes

McCutcheon Construction, Inc. — cutting-edge Berkeley green builder

Build It Green — nonprofit organization promoting green building

Recycled building materials:  ReStore, Oakland (Habitat for Humanity); Urban Ore, Berkeley; Ohmega Salvage, Berkeley; Craigslist for recycled wood

Home performance evaluations:  Recurve or BPS

Low Impact Living

Green Home Guide answers to green building questions

StopWaste.org Alameda County waste reduction

United States Green Building Council

National Association of the Remodeling Industry

Affordable Comfort home performance website

The annual West Coast Green conference and expo

Michael Pollan’s book: Omnivore’s Dilemma

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