Planning and Design

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1. Proper site planning

Design of floorplans and foundations should reflect the site topography.

Split level plans, terracing, and decks can help integrate built features into site conditions and minimize the cost and effects of grading.

Building orientation on an east-west axis with glass area minimized on walls with maximum solar exposure will decrease energy demands for cooling, particularly when combined with proper placement of shade producing plants.

2. Preserve and protect as much existing vegetation as possible.

Incorporate existing trees when locating structures and powerlines, allowing room for them to grow if they are not at mature size. (The city's Land Development Code tree preservation regulations controls commercial and multi-family construction projects. Under these rules, trees with a trunk caliper of 8 inches or more must be included in a tree survey, and trees with a 19-inch caliper or more are considered protected.)

Protect trees from damage during construction with clearly visible fencing located below the outermost branches (see Figures 1 & 2) and flags in overhanging branches. See illustrations for where to locate fences. (According to surveys conducted by Builder Magazine, trees can increase the value of a home by up to 15%.)

Wooden slats attached to tree trunks will not provide adequate protection. Much of the damage that occurs to trees during the construction process is due to soil compaction from heavy equipment and materials being driven or stored under trees. Roots which extend out far beyond the trunk are damaged when soil becomes compacted. This will cause trees to go into a gradual decline, and eventually die.




Filling or cutting in tree root areas will also kill trees. Use tree wells or decks to work around tree trunks, roots and slopes.



Avoid trenching in tree root zones; try tunneling instead to locate buried utility lines.

If areas around trees must be paved, use pervious materials (see section on Pervious Paving) or, at a minimum, leave large holes spaced at regular intervals in the tree's root zone (openings will help give trees needed air and water).

Never dump paints or solvents near trees. These cause plant death and soil contamination. Dispose of all waste materials properly.

3. Preserve and protect topsoil on construction sites.

Topsoil is a valuable resource which can only be replaced with expensive hauling from other sites, or with many years of the natural process of soil formation. In areas where topsoil must be stripped:

Collect and stockpile the topsoil for future use on the site.

Place erosion control devices such as haybales or erosion control fencing in all areas where construction disturbs the soil. (Such devices will help prevent the loss of topsoil during rainfall, when soil can be washed downstream causing site losses and non-point-source pollution.

4. Stabilize or cover all bare soil areas by the time construction is completed.

Extreme slopes, hillsides, and stream banks can be stabilized with vegetation, terracing, dry stack limestone, rubble, or rip-rap.

In landscaped areas, a thick layer of organic mulch should be applied to planting beds.

Planted slopes can be covered with erosion control fabrics or jute netting before groundcover or other plantings are added. This will help hold soil in place during the plant establishment period. Shredded mulch which tends to form a mat should be used in sloping areas, as it tends to wash out less than other types.

5. Landscaping for energy conservation should be an integral part of any landscape design.

Plant deciduous trees on the west and southwest sides of structures. Such trees can create enough shade to lower roof and wall temperatures by up to 20 degrees.

Deciduous trees that lose their leaves in winter will create summer shade and allow sunlight through open branches to warm and light the home during winter. (Note that with leaves off, there can be significant shading from the branches.)

Shade can also be created by using a combination of landscape features, such as shrubs and vines on arbors or trellises.)

Shade the outdoor compressor unit of an air conditioning system. This can help save up to 10% on summer cooling bills. Be sure to leave room (at least 3 feet) for air flow and service access.

Natural cooling without air conditioning can be enhanced by locating trees to channel southeasterly summer breezes. Cooling breezes will be able to pass through the trunks of trees placed for shading.

See also the Sourcebook chapter on Landscaping for Energy Conservation

5.1 Create living windbreaks to block cold winter winds.

Plant evergreen shrubs and/or trees on the north and northwest sides of a building. Varieties that branch all the way to the ground are most effective.

Several staggered rows of plantings should be located on the leeward side of the wind.

For best wind protection, plant windbreak trees a distance from the house equal to 5 to 7 times the height the trees will be when mature. (For example, if planting a windbreak whose mature height will be 25 feet, locate it 125 to 175 feet (5 to 7 times 25 feet) from the building.)

See the Energy section of the Sourcebook for more information on landscaping and site planning for energy savings.

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This file last updated on Friday, August 4, 2006