Accurate Survey Information

For projects ranging from small accessory structures and additions to new construction, it is important to understand the value of accurate survey information.

Land Survey Frequently Asked Questions

The various survey products, their respective limitations in being used as base drawings for permit applications, and other information frequently needed on site plans are outlined below.

*Note that this is intended to provide supplemental information, and not meant to replace Ordinance No. 7684

  • Improvement Location Certificate (ILC): This type of survey is primarily used by mortgage and/or title companies to assist in residential property transactions. This certificate typically documents the location of improvements upon a parcel of land and graphically shows the location of easements and/or other encumbrances affecting the property as disclosed in information provided by the title company. Typically, the surveying methods used in the preparation of an "ILC" are not sufficient to precisely determine the location and dimensions of property lines, or the exact location of improvements upon or adjacent to the subject property. Therefore, an "ILC" should not be construed to be a land survey plat or an improvement survey plat. By State law the professional land surveyor who prepares an "ILC" must use a mandated certification that includes the following phrase: "...that it is not to be relied upon for the establishment of fence, building or other future improvement lines..."
  • Land Survey Plat (LSP): This type of survey is what is commonly called a "boundary survey". After being provided with a current legal description of the subject property, a professional land surveyor reviews title information as well as deed information of adjoining properties. A thorough effort is made to recover monuments in the field, oftentimes including public land monuments (e.g. "section corners", "quarter corners") not necessarily adjacent to the subject property. Precise field measurements are made, field data calculated, and property corner positions determined by careful analysis. Frequently, legal descriptions of the subject and adjacent properties are in conflict with field measurements. The professional land surveyor documents these conflicts and prepares a detailed plat of the property boundary, setting the necessary property corner monuments in the field. If the land surveyor has been provided with the appropriate title information, the land survey plat will also show the position of easements, rights-of-way and other encumbrances affecting the subject property. A land survey plat does not document improvements on the subject property, except where they are adjacent to the property lines.
  • Improvement Survey Plat (ISP): This type of survey is similar to a Land Survey Plat but, in addition, documents the improvements upon the subject property. Improvements on adjacent properties that encroach into the subject property are also documented. In most cases, Land Survey Plats and Improvement Survey Plats are deposited at the Office of the County Surveyor for public access. In Boulder County, these maps are deposited at the Boulder County Land Use Department.
  • Topographic Survey: this type of survey typically determines the "lay of the land", its slopes, contours, etc. Typically these maps document existing improvements, significant trees and plants, and patterns of drainage. Often architects or planners use topographic maps to plan future projects. Topographic maps may or may not contain boundary line and easement information.

In general, permit applications for Accessory Buildings that:

  • Do not result in a project that is greater than 80% of the maximum allowable floor area per the Floor Area Ratio requirements or greater than 80% of the maximum allowable building coverage, and
  • Single story accessory buildings with walls less than 14’-0” measured above adjacent finished grade, and
  • Accessory buildings located more than 4’-0” from the property line.

In general, applications for New Dwellings or Additions that:

  • Do not result in a project that is greater than 80% of the maximum allowable floor area per the Floor Area Ratio requirements or greater than 80% of the maximum allowable building coverage, and
  • Single story additions with walls less than 14’-0” measured above adjacent finished grade, and
  • Located more than 1’-0” from all minimum required setbacks (including total side yard, solar, bulk plane, etc.)

*The City reserves the right to reject an I.L.C. that is not current and/or does not provide adequate field references demonstrating a reasonable level of field survey work to verify property line locations.

Solar/Bulk

For buildings over 12’-0” in height, additional grade information may be needed to demonstrate compliance with Solar and/or Bulk Plane regulations (spot elevations at property corners, mid-points/10’ intervals, and at grade break locations along property lines.)

Floor Area Ratio (FAR)/Side Yard Wall Articulation (SYWA)

For buildings with partially exposed lower levels and/or walls over 14’-0” in height, existing contour/topographic information (pre-construction/excavation) and finished grade information (post construction/site work) may be needed to verify the amount of contributing floor area of partially exposed lower levels toward the maximum allowed FAR, or to calculate wall heights for compliance with SYWA.

Overall Building Height

  • For all buildings: the location and elevation of the lowest point within 25’-0” of the resulting building, to be used to measure overall building height.
  • For buildings within 2’-0” of the maximum allowed height: the location and elevation of the lowest point within 25’-0” of the resulting building, as determined by a surveyor, to be used to measure overall building height.

In general, when a Land Survey Plat (LSP) or Improvement Survey Plat (ISP) is not otherwise required (the result of the type or scale of project as it relates to other regulatory tools) applicants may provide on a form provided by the city a lot area declaration signed by a surveyor, architect, or engineer. In those instances information from a current ILC or detailed Subdivision Plat may be used as the basis for calculating lot area.

If an LSP or ISP is required, then the lot area shall be reflected on that survey document.

Setbacks

Prior to framing inspection approval an updated ILC or ISP (depending on thresholds described above) may be needed to verify compliance with minimum setback requirements.

Solar/Bulk

Prior to framing inspection approval, those elements of the building near the maximum heights allowed for solar/bulk plane may require a height confirmation survey.

Floor Area Ratio (FAR)/Side Yard Wall Articulation (SYWA)

If, because of a partially exposed lower level, the resulting development on the property is near the maximum allowed FAR, or if proposed wall heights are near the maximum allowed for SYWA, a finished grade certification by a surveyor may be required prior to final inspection approval.

Overall Building Height

Prior to framing inspection approval a height verification survey may be needed to verify compliance with maximum allowable building height.