Grade Differential
Lot grading with substantial grade differences, from the side of the house to the rear of the house, usually occurs on walk-out basements.
Grading approval for these homes may require retaining walls at the rear corners of the house, or on the side lot. These retaining features are usually indicated on the plot plan.
The grading of the common property drainage swale must allow for 10% slope from the foundation walls of adjacent houses, and must provide drainage functionality for both properties.
Any retaining wall that exceeds 0.6 m in height, or is attached to the house, should attach an engineered design. A permit or design requirements can be obtained from Sustainable Development of the City of Edmonton. Call 311 for details.
The following pictures and diagram are the examples for the requirements to deal with grade differential (for reference only):
These 2 lots have a large grade differential
A retaining wall attached to the walkout basement
This walkout basement needs retaining walls
This is an engineered retaining wall design example
For More Information
Drainage Planning and Engineering
5th Floor, Century Place
9803 - 102A Avenue NW
Edmonton, AB
T5J 3A3
| Telephone | 311 or 780-496-5576 |
|---|---|
| Fax | 780-496-2865 |
| lot.grading@edmonton.ca |
