Understanding Home Construction: Site Preparation

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Choosing the site is the very first step in building a house. It influences not only building techniques but almost every other aspect of the homebuilding process.

Selecting the Site

Slope, access, drainage, vegetation, and many other site characteristics can affect the style of a home. A highly sloped lot may favor a split-level home. A broad, flat lot may favor a ranch-style home. Nearby water or underground rock may prohibit construction of a basement, while a narrow access may prevent the delivery of large components such as beams or broad glass panels.

Since a home is designed with the site in mind, once the site is selected the builder must consider the following:

• location of the home that makes best use of the natural grade and slope, keeping in mind drainage and aesthetics

• natural features, such as foliage, bodies of water, and other site geology, that enhance the final landscaping

• position of the home on the site relative to other features to reduce construction costs

• direction of the home that makes best use of the location of the sun, balancing energy conservation with aesthetics

If all else is equal, a home on a perfectly flat lot will cost less to build than a home on a highly sloped lot. This is because the costs are higher for the bricks, mortar, concrete, and labor required to build the larger, irregular foundation for a sloped lot. With some sloped sites, the builder may need to rent a crane or other machinery to lift materials that would have otherwise been moved by hand.

Determining Slope and Drainage

More than any other factors, the slope and drainage of a site affect the construction of the foundation. For example, a flat site is most practical for a slab-on-grade home discussed in Section 2. In contrast, a steeply sloped lot lends itself to a home with a basement because the depth of a basement allows the grade to angle down the sides of the house and assist with basement drainage. (For examples of basement drainage and slopes for basement drainage, see photo 1.1 and drawing 1.2.)

1.1 Basement Drainage

1.2 Slopes for Basement Drainage

A flat site or a site with a gentle slope permits the natural drainage needed for the construction of a home with a crawl space. A crawl space is an unfinished area between the ground and first floor large enough for a person to crawl through. A crawl-space home often uses a pier-and-curtain- wall foundation. This type of home sits on piers that are then screened by a low wall around the perimeter of the foundation.

Other site features that affect the type and construction of the foundation include—

• rock outcroppings

• shallow depth to bedrock

• shallow groundwater

• location of natural drainage ways through the site

• dense vegetation

From the beginning the builder needs to plan the final landscaping and erosion control. Regardless of the size, cost, or style of the home, these are serious considerations. Whether a new homeowner has a $10,000 landscaping budget or plans to sow a handful of grass seeds, the final grading of the site can affect the appearance and long-term value of the home.

Addressing Legal Considerations

Virtually all areas of the country have agencies such as zoning boards, planning agencies, planning councils, or development boards. Many subdivisions also have architectural review boards provided for in their charters and mandated in the deed restrictions for the lot. Federal, state, and local environmental restrictions may also apply.

What does all this mean for the builder? Plainly put, local officials want to ensure that all homes and businesses fit into a cohesive master plan, that shared resources such as utilities and storm drainage are fairly allocated among landowners and dwellers, and that community neighborhoods are protected from inappropriate land use. In many cases, this may require careful integration of new homes into existing neighborhoods. (See drawing 1.3.)

1.3 Cross Section of Proposed and Existing Development

A lot usually has utility easements running along the front and possibly the side and back edges of the yard. A utility easement is the right of the local utility companies to run water, electric, gas, telephone, and sewage lines through certain areas of the property.

The local utility companies have more or less free access to install, maintain, and replace utility lines either above or under the ground in easement areas, so a builder should not build anything permanent within these areas. For example, if a homeowner plants prized gardenias in an easement area, he or she may come home one day to find a utility truck parked in the middle of them.

Utility easements can even cross the middle of some lots. As a result, when developers plan a subdivision, they realize that some lots are less desirable for building due to the need to place underground water, sewer, or drainage lines through them.

A lot can be less desirable for building for other reasons as well. Dune lines or mean high-tide setback lines, which prohibit building on certain low-level lots, affect many coastal neighborhoods. Some lots in such areas may even be lower than the 100-year floodplain designated by the federal government, which may render a home on such a lot uninsurable. A floodplain is land that may become covered with water when floods occur and the 100-year floodplain is the height to which water is anticipated to rise within a 100-year storm event.

None of these site conditions is necessarily obvious. The builder must do a bit of research and carefully examine a development site to determine its appropriate use. Once the builder has formed an opinion that a site is buildable and determined the usage or architectural restrictions that may apply to the site, the builder must then navigate through the permitting process. This process is often complex and can become time-consuming and costly. Although the permitting process can take from one month to a year or more, an experienced builder can steer the plans through the process and obtain permits in the shortest time possible.

As part of a permitting process, a zoning or planning board must certify that a proposed home is within the bounds of the local zoning ordinances. An architectural review board in a subdivision may have to attest to the aesthetic quality of the design for the home. Members of this board may want to look at such things as plans, elevations, paint colors, designs for landscaping, and samples of siding or roofing materials. The utility board may want to certify that water and sewage service is available.

A building official will have to certify that the house plans meet all of the local building codes. If the builder or home owners want to drill a well or install a septic tank on the site, they will have to receive advance permits from the health department. The cable television company may even become involved in issuing a permit for the new home.

Preparing the Site

Once the legal hurdles are crossed, the builder begins the physical process of constructing the home. The first step is clearing the actual house site and driveway for the delivery trucks. At this time, the builder may also remove large trees and other vegetation as needed, perform rough grading for the eventual landscaping, and make early provisions for anticipated drainage patterns.

The builder will then stake out the house by locating and marking all of its corners and ensuring that its final position matches the site plans. (See photo 1.4.) Stakes are then driven into the ground to mark the exact location of the house. At this point the builder also needs to take care of several house keeping chores, such as locating the temporary power source, marking the location of eventual water and sewer taps, and working with the public utility company to ensure that no additional easements are necessary.

1.4 Stake-out

So, after selecting a site, the builder can plan the house on the site to achieve the best use of the natural grade and slope for drainage and aesthetic purposes, while at the same time keeping construction costs down. The builder must then complete the permitting process before preparing the site for construction. Once through the permitting process, the builder can clear and grade the site and stake out the house. Then the next major step in building a house is constructing the foundation.

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