BLD20150060reviewcommentswithattachment.pdf
#B41
Height Calculation Information
PROCEDURE:
Height must be calculated prior to any on-site grading or alteration of topography. It
is understood that in rare occasions vegetation may have to be removed in order to gain access to grade.
On formal subdivisions of property, a topography map is usually included in the recorded documents
on file with Snohomish County or City of Edmonds. It is highly recommended that applicants utilize
these maps for determination of height.
1. To determine the maximum height permitted on a site, stake out the smallest rectangle (within the
boundaries of the site) that encompasses all four corners of the proposed building outline/building
pad at original, undisturbed soil.
2. Projections such as bay windows must be included within this rectangle.
Exemptions:
Chimneys and eaves projecting no more than 30 inches from the exterior wall of
the building and uncovered decks.
3. Select a datum point to establish a starting mark to compute grade elevations at the designated
four corners. The datum point must be a permanent point of reference. Use the top of a manhole
cover, fire hydrant, or street monument. Reference the datum point elevation at +100. On the
site plan describe the datum point and show its location and elevation.
4. Calculate the difference in elevation from the datum point to each corner of the rectangle (above
or below the starting elevation of +100) at original, undisturbed soil. Next, add the four corner
elevations together and divide by a factor of 4 to determine the average grade of the building pad.
On the site plan show the elevations of the four corners and show the calculations of average
grade.
5. Take the average grade number and add the maximum allowable height per the specified zoning
district. This elevation is the maximum height allowed for the proposed location of the building.
In the attached example, the single family average grade is +102.5, add +25 feet, for a maximum
height of +127.5. As shown on the plot plan the actual height of the building is +125. Be sure
the average grade, maximum allowed height and actual height are noted on the plot plan and
elevation view.
plot plan
6. As in the example on the submitted show all height calculations, the elevation of each
corner, the datum point, the average grade, the maximum height allowed and the actual height of
elevation views
the building, and on one of the within the architectural plans, show the average
grade, the maximum height allowed, and the actual height of the building.
Revised 9/2010
#B41
7. Height field verification shall be done by the applicants agent/contractor and observed by the
building inspector. The agent/contractor shall set up the equipment; establish the datum point
and the point of average grade. These items must be consistent with the approved plan.
If the proposed height of a building (as shown on the plans) is within 12 inches of the maximum
height permitted for the zone an elevation survey is required. An elevation survey consists of
three components, to be conducted by a licensed surveyor.
Prior to construction the surveyor shall establish average grade as specified in ECDC
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21.40.030, and shall establish a reference datum point that will be undisturbed and can be
freely accessed.
The surveyor shall locate the elevation of the first floor prior to the City under-floor
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inspection,
A final letter of height confirmation shall be provided upon completion of the structure.
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Revised 9/2010