How Zoning Works: Surveys

Normally, a survey is required when you are building a new construction project. A soil report is required when you are building a free standing new construction project. A wastewater permit is needed for almost any building permit.

  1. The purpose of the survey is to provide the exact location of the existing property lines and the position of all the structures inside the property lines. At the time of this printing, the city of Denver still has overlapping requirements for surveys. To do it right, a survey is required for most cases.
    1. The main difference between a surveyor and another professional is that surveyors have the right equipment. Fences and other markers normally occur on property lines but it’s not uncommon for these items to be more than a foot off.
    2. Surveys help determine the exact location of setbacks, addition attachments, and so on. The type of survey needed is called a “boundary survey”.
    3. As an inspection requirement, a surveyor must locate the side lot setback distance from the concrete forms to insure that the foundation does not encroach.
    4. Also, the survey shows the vertical position of the property corners and the front bulk plane relative to a city-wide system of “elevations”. For instance if the front corner of the lot is 99′, then we know that the front corner of your lot is 1′ below the standard 100′ located at a central point in Denver.
    5. It’s nice to have this information but the real issue is to establish the base plane (or the foot) of the bulk plane. You’d be surprised at how many disputes are resolved because the exact numerical position of a neighboring bulk plane is known. This is determined by taking an average between the two corners.
    6. As another inspection requirement, after the framing stage, an inspector verifies that the project doesn’t penetrate through the bulk plane. Theoretically, this is enough time to make changes if needed. Obviously, this process is more accurate if you start with a survey.
    7. Surveys normally cost between $500 and $800.

Please let me know if you have any questions regarding the above.


Steve Culbertson
Landmarkk

How Zoning Works: Soil Reports

Normally, a survey is required when you are building a new construction project. A soil report is required when you are building a free standing new construction project. A wastewater permit is needed for almost any building permit.

  1. The soil report is less legal and more important from an engineering perspective.
    1. A hole is drilled in a convenient location on your property and the core sample is analyzed by an engineer. The engineer then creates a report which tells your architect/engineer the bearing capacity of your soil to support the weight of the new structure.
    2. With the capacity of the soil, usually expressed in lbs./sf, we know how big to make the foundations. In addition, the report will state how wet the soil is and its’ ability to drain moisture away from the foundation. In some cases, soil has a high clay content and has a tendency to swell as it gets wet. If this isn’t solved, your basement can crack.
    3. If your new structure is located within a few feet of an adjacent neighboring property line, you will need additional “shoring” to prevent the soil from caving in and possibly collapsing your neighbors building. Typically, this is a design which must be prepared by the soil engineer.
    4. Soil reports also normally cost between $500 and $800.

Please let me know if you have any questions regarding the above.


Steve Culbertson
Landmarkk

How Zoning Works: Allowable Bulk Plane

The bulk plane is really a series of planes which limit the allowable volume of space the building can occupy. As with the height limitations, the bulk plane requirements are separated into limits for the front 65% of the lot and the rear 35%. The purpose of the bulk plane is to allow adjacent neighbors access to sunlight and to maintain privacy. Because of the sunlight requirement, the planes follow the length of the property and slope inward at a 45 degree angle. Typically the vertical leg is 17′ in front and 10′ in the rear and is horizontally located above the property line. The top plane is determined by the building height limitation. To learn more, see the bulk plane drawings in this section, page 13.1-16, and figure 13.1-21.

Because the bulk plane can cause acrimony between neighbors, especially in cases like ours with city infill projects, the measurement requirements are very detailed. The information below is spread over several chapter 13 pages.

  1. Base plane .. The base plane is an imaginary horizontal bottom plane from which the vertical legs of the bulk planes are measured.
    1. The vertical position of the front base plane is determined by an average of the vertical spot elevations, shown on the survey, at the face of the house (not the porch) plane which intersects the property line.
    2. As an example, if the west spot elevation is 94.00 and the east spot elevation is 96.00, the front and back edges of the base plane are at elevation 95.00. The rear base plane is the same except that the vertical spot elevations are taken at the rear property corners. To learn more, see page 13.1-2.
  2. Side wall height .. Depending on the chart shown on page 5.3-5, the side wall is typically 17′ in the front and 10′ in the rear. Page 13.1-16 shows some very specific rules of measurement, but 17′-10′ is ok for our purposes.
  3. 3. Height .. The height of the bulk plane is shown on page 5.3-5 but for our purposes is typically 30′ in front and 17′ in the rear. See page 13.1-12 to learn more.

Please let me know if you have any questions regarding the above.


Steve Culbertson
Landmarkk