A house site plan in layman's terms show how your house will sit on your property in relation to location, lot slope, and orientation. When part of a custom and detailed set of architectural blueprints, the site plan is the page that follows the title sheet. Site plans are developed in stages with coordination from a civil engineer's plat map and topography map. The primary role in the plat is to provide a guide of the property lines and land dimensions so that the building designer has a frame of reference as to how wide and deep the home design can and should be. Once this variable is known, then the preliminary design can get underway. The topography map is much more detailed showing the contours and their accompanying numerical elevations of the site. In essence, it is actually a plat map with more complete and thorough details.
When looking at a topography map, it can appear complex and just plain intimidating to the untrained eye. But to a building designer, it speaks a language that they clearly understand. From this illustration, we are able to understand important details about the lot that include, easements, setbacks, existing trees & foliage, land slope (contours), and the property orientation in reference to true north. If necessary, boring test are also indicated to explain soil conditions. From this information, we are able to complete the house site plan by adding the footprint of your home to the map and adjust land conditions accordingly.
To adjust the land properly, the designer creates a grading plan to show how the topography will change to accommodate the building design. In other words, the contours are redrawn in a way that will remove soil (cut into existing contour) or add soil (fill into existing contour). This so-called "cut and fill" procedure does two things. First it provides for a level ground surface area for the house location and second, it shapes the land to slope water away from the home on all sides of the building. It will indicated the new (finished) grades which are shown in solid lines to contrast with the broken lines of the existing grade. With the new grades, the floor elevation for the building is established at the highest point. The home is positioned on the lot in the best location to take advantage of everything the building lot has to offer. This include views, solar energy, use of trees and whatever else is available.
Whether you use a set stock house plans or go with a custom home design, a house site plan is necessary. It will be required by your local building department as part of the items that are to be submitted in order to obtain a home building permit. With stock plans, your builder will likely use the services of the civil engineer to locate the house on the site. This also may hold true with custom designs sometimes; however, using a building designer to provide this service is a more desirable option. Because the designer spent weeks or month developing the designs, both stock and custom plans, he is familiar with every aspect of the building. This puts the designer in a better position to provide a solution to place your home on the lot. With that kind of insight, the designer will consider things such as slope conditions, solar conditions, and other design considerations in reference to your home that may be missed by others.
The next page in a set of house blueprints is the foundation plan sheet