Tag: green

A green home is designed to use much less energy than a standard home. Some of this is related to construction techniques — a tighter seal and better insulation all around prevents heat loss (or heat gain in the summer). With a heat-recovery exchange system you can still get healthy ventilation without losing all the heat from your house. Similarly, using very insulated windows with heat glazing can help keep out the sun when it is hot and keep in or out the heat from leaking through.

But a lot of the energy efficiency comes down managing solar energy as well as possible. In the winter, you want to capture as much sun as possible to heat your home naturally. This means taking advantage of the fact that the sun is higher in the sky in the summer than in the winter. In many locations, a green home will be built with south-facing exposure to capture the sun the winter sun. To prevent the higher summer sun from entering, a green home can have eaves over the windows at the appropriate angle and extent to block most of the sun in the summer. Clerestory windows and light shelves help bring light deeper into rooms to avoid using electric lights (and without transferring all the heat in the summer, too).

Bedrooms can be put on the east side of the building to take advantage of the morning sun (although around here, that needs to be balanced with getting sun too early in the summer). Rooms that you use at the end of the day, for example, the dining room or office, can be put on the western end of the house.

Proper orientation with respect to sunlight is probably one of the biggest advantages for the homeowner — having the right light in the right room at the right times of day can make a home feel very livable, inviting, and comfortable. Getting the layout right requires more thought than a cookie-cutter plan from a book, but the resulting home will likely have a better layout and be more usable.

Of course, you can also analyze the suitability of your site for wind power and photo-voltaic array. A green home can be pre-wired for solar at a minimal cost (hundreds of dollars added to the total cost of the home). Even if solar power isn’t economical now, it may be in 5 or 10 years as prices on PV cells come down; being able to install them and connect them to existing wires will be much cheaper than trying to retrofit the wiring.

Green materials are usually natural, made from renewable resources, or use low-energy manufacturing techniques. Some people consider materials sourced and processed locally to be more green than those that are not. Some materials combine these properties, but not all of them do. For example, bamboo cloth is made from a natural and renewable resource (bamboo grows very quickly), but it requires a lot of nasty processing to make it into suitable cloth.

For wood, this usually means avoiding exotic woods that are from endangered species, or have to be shipped from far away. There is plenty of nice renewable hardwoods available from the US. A green home can use salvaged wood (e.g., from old buildings) that has some interesting character to it. Salvaged woods do not need to be harvested, and salvaging saves them from the dump. However, some sources of salvaged wood may have toxins, so it should be obtained from a reliable source.

Marble or quartz is not very renewable, but many manufactured stones are made from recycled materials. Paperstone is made of recycled paper bound together with resins. NovuStone creates counter tops from recycled glass; the glass is sourced and processed in the Pacific Northwest.

A green home would avoid most synthetic carpets. These carpets are made from petroleum producs and use nasty treatment chemicals to make them flame retardant. Natural wool carpets provide a green alternative, and they are naturally flame retardant.

Green homes avoid using paints with lots of VOCs and use low-VOC or zero-VOC paints made from plant oils or natural minerals instead.

These materials often provide benefits for the home owner as well as the environment. Low-VOC and zero-VOC paints improve air quality — the air is cleaner from the beginning, and you don’t have to worry about any possible health effects (VOC concentrations can be up to 10 times higher indoors than out). Wool carpets also reduce the amount of VOCs in the air. They can also be more durable, more stain resistant, and are less prone to collecting dust mites. Plus, they often feel a lot nicer. Of course, this comes with a cost. Wool carpets are significantly more expensive than their synthetic counterparts.

Synthetic and manufactured stones often come in a wider variety of styles an colors than natural stone. Some can be made to custom-order. Some types of manufactured stone counter top can be created as a single slab (which makes cleaning easier).

What does ‘green building’ really mean? There are certifications that describe this in more detail: LEED is a common one, though early on it was more targeted towards commercial buildings; BuiltGreen is a standard aimed at residences in Western Washington. But what does green building entail, and what does it mean for the home owner?

Green building aims to reduce the impact of a house on the planet through construction techniques, material choices, and building design (particularly related to energy usage).

Not everything described here is applicable to every development; in particular, not everything listed will be used for the Taltree development. This is more a general overview of the types of things available for green building.

Each area will be considered over the next several posts.

Green construction techniques try to cause the least possible disruption of the site and avoid wasted materials. For example, for the Taltree site, the builder wants to save as many of the existing trees as possible, especially the important trees and tree groups. In today’s standard development practice, the land is cleared entirely, then completely replanted with grass and a few new trees. The Taltree site has a lot of really nice, older trees. When possible, these trees will be left in place. If there are mature, healthy trees in planned building areas, the trees will be carefully moved to a new location to keep them alive. This avoids throwing away a lot of cut-down trees, avoids the need to buy a bunch of new trees that will take years to grow, keeps around trees that are comfortable in the native climate and so don’t need a whole lot of work to keep them healthy, and provides much nicer surroundings from the very beginning for the residents.

There are a variety of techniques for cutting down on wasted materials during construction. One example is using pre-fabricated panels called SIPs (structural insulated panels). These are used for the wall, and are fabricated to spec in a warehouse; so they are manufactured to the correct size, and they are assembled just like a puzzle on site. This means no cutting boards down to size or anything like that, which results in very little waste.

Advanced Framing is an an alternative to SIPs. This framing technique reduces the amount of lumber used, achieves the same strength as standard framing techniques, and increases the thermal efficiency of the home.