Green Building Begins with the House Lot and How You Use It
ABOUT GREEN BUILDING LOTS
Be mindful of the landscape as well as the building. We spend a lot of time thinking about the components of a new house: windows and doors, insulation, the heating and cooling system. But, in terms of green success, some of the most important planning goes into the surrounding site.
In the short term, limiting construction damage to the landscape is high on the list. In the long term, however, success depends on how well the house is integrated into its surroundings. Even a thoughtful building design won't reach its potential if the site is an afterthought.
Not all site damage is clear-cut. Site-work vehicles intentionally alter the building site; building a new home on a new lot disturbs the landscape. Topsoil and vegetation are removed; less stable sub-soil is exposed. Steeper sites are more prone to erosion. Carelessness here can lead to long-term damage.
Construction vehicles can damage the surrounding landscape in obvious ways: A tree takes a direct hit from a piece of heavy equipment, or the grade within a tree’s drip line is raised or lowered. Raising the grade with extra fill can suffocate roots; lowering the grade destroys them. Other, perhaps unintentional damage such as vehicular traffic is not so obvious. This compacts the soil, which is bad for plants. Roots don’t get as much oxygen and the soil doesn’t absorb as much water, suffocating and starving roots and contributing to erosion.
Planning ahead reduces long-term damage to soil, plants, and trees. To do the least harm to the environment around your building site, be prepared. Get the information you need. For bigger picture solutions consult LEED for HomesLeadership in Energy and Environmental Design. LEED for Homes is the residential green building program from the United States Green Building Council (USGBC). While this program is primarily designed for and applicable to new home projects, major gut rehabs can qualify. or the NGBSNational Green Building Standard Based on the NAHB Model Green Home Building Guidelines and passed through ANSI. This standard can be applied to both new homes, remodeling projects, and additions. . They offer guidance on slope and site disturbance, erosion control, storm-water management, and a landscape plan that considers native and invasive plants.
Some of the following common-sense suggestions were taken from LEED for Homes and NGBS. They can make a big difference in the long-term health of the landscape around your building site:
- Install a fence beyond the tree’s drip line – the area beneath the outermost branches – to protect it from soil compaction.
- Create terraces or large-diameter wells to maintain existing grades around trees.
- Create clearly-marked no-vehicle zones.
- Limit vehicles to permanent roads or designated parking areas.
- If vehicles must drive over the trees’ roots, cover them with 3 in. to 4 in. of wood chips, wooden planks, or sheets of plywood.
Significant trees or landscapes need extra protection. The best way to ensure their protection on a building site is to award incentives or assess penalties that make it worthwhile for contractors to be careful. Consider rewarding excavators and other project contractors when they are extra careful. Alternately, you can incorporate a penalty clause into contracts so that if designated trees are injured in the construction process, the contractor is liable.
Properly protecting trees can be expensive. But, mature trees can increase property values, shade trees reduce cooling loads, and last, but not least, they provide important wildlife habitats.
Finally, trees unlikely to survive should be removed and replaced by native species that will adapt to altered site conditions. Mature trees lovingly “saved” with inadequate protection die within the first year of occupancy.
How to Pick a Green Building Lot
Five tips to help you pick
Build on infill lots such as vacant adjacent lots, brownfields, grayfields, and lots in depressed neighborhoods. The services are already in place, and the price might be great.
Don't build in sensitive areas. Floodplains as defined by the Federal Emergency Management Administration, habitats for endangered species, and other environmentally sensitive zones are not appropriate for building.
Existing utilities are greener and cheaper than bringing in new ones.
Keep close to community. When services such as schools, shopping, and public transportation are near great housing, people travel less and the whole community is greener. Community gardens are another way to green up a neighborhood while bringing members closer together.
Find out what the property was used for in the past.
Previous uses for the property might have introduced chemical contaminants, such as lead, pesticides or petroleum products. Farming, including orchards, and industrial and commercial operations all have the potential for leaving contamination behind.
MORE ABOUT BUILDING LOTS
Good siting gives the most bang per buck
How well a house sits on its site can affect heating and cooling costs. The surrounding landscape plays a big role, if you let it, and how you manage water (drainage, to be specific) can directly affect the long-term durability of the house. You should also swap impermeable surfaces, like asphalt or concrete driveways, patios, and walkways, for permeable ones—hardscaping matters, especially in densely settled areas.
Sun  No single site characteristic affects a home's energy performance and comfort more powerfully than the sun. In cooler areas, there is tremendous potential for using the sun to provide heat even without elaborate mechanical systems. In warmer zones, managing sunlight ensures a more comfortable house without using a lot of energy. Making the most of a site's daylight potential is important no matter where the house is built.
Drainage  In all but the most arid climates, sub-surface water and runoff from rain and snow are facts of life. Good water management means keeping it out of the house and in the ground. Water that runs off into the street can overload storm drains and dump pollution into rivers and lakes. These consequences are best thought out in the initial phases of construction.
Landscape  A goal of good design is creating a house that looks like it belongs in its setting. Consider two issues: the natural features on the site before construction; and how the site should look like when the house is done.
Hardscape  Driveways, decks, patios, and sidewalks are necessary to get people and vehicles to and around a house. These hardscape elements also have big implications for water management and overall aesthetics.