Development Engineering Site Plan (DESP) Guide

Site plans and zoning

A Development Engineering Site Plan (DESP) approval is required for all residential rebuilds and major additions on those lots which are zoned:

• RL1-0
• RL2-0
• RL3-0
• RL4-0
• RL5-0
• RL6-0
• RL7-0
• RL8-0
• RL10-0

If the zoning is not included in the above list for residential properties, in accordance with the Site Plan By-Law, a DENG permit is required. 

Major additions are defined as increasing the first floor footprint of a building by 50 square metres or more. If the footprint is not increasing, then a DENG permit is required.

Visit the Development Engineering Permit Guide page for information on that type of permit.

DESP submissions

Your DESP submission will be reviewed to ensure there are no impacts to adjacent properties and includes the following reviews:

• Grading
• Drainage
• Trees
• Servicing matters

DESP approval is required prior to being issued a building permit, but the two processes can be underway at the same time.

Submission requirements

Submission requirements for a DESP application include:

• Completed Development Engineering Permit Application
• Digital copy of the plan(s) certified by a professional engineer or other qualified persons
• Application fee as per current Rates and Fees by-laws
• Digital copy of a stormwater management report
• Digital copy of an arborist report
• Digital copies of any other permits or sign-offs required (both town and external agencies)
• Securities (e-transfer, EFT).

Drawings, plans and reports

Sufficient detail on the drawing is required to demonstrate how the plan will function. Elevations that demonstrate both existing and proposed grading and drainage are needed on the plan(s). This includes existing grading information for adjacent properties, up to five metres offset of the property line, whenever possible.

Proposed servicing shall also be shown clearly on the plan(s). This information, in combination with that provided within the stormwater management, must demonstrate that there will be no impacts to adjacent properties and that drainage is self-contained on the subject property. 

In some older areas, where drainage swales have flattened over time, additional runoff can cause drainage issues. Our review will make sure existing drainage patterns are maintained or improved and that impacts from additional surface drainage can be avoided. A qualified professional must prepare the stormwater management report.

Proposed grading, drainage and servicing must be in accordance with the town’s standards and the Development Engineering Procedures and Guidelines Manual including Addendum 1.

• The plan(s) should make it clear how the proposed grading will tie into the lot line drainage, as well as how roof leaders will be directed and swales graded to make sure that drainage patterns are transparent.
• Sufficient grading information is needed to show that proposed swales can be constructed as designed. Only stating two per cent swale within an area without supporting grading details will not be acceptable.
• Existing capacity for connecting a sump pump to the storm sewer in many areas south of the QEW is at or near to capacity.
• Rear lot catch basin, infiltration or retention methods may be required to decrease higher flows prior to the connection to the storm sewer.
• Where no existing defined outlet exists for the lot, infiltration or retention will be required.

Arborist report

The arborist report must be prepared by an arborist licensed with the town as per the Procedure for Tree Protection during Construction. The report must consider both private trees and municipal trees.

Specific details required include:

• The diameter at breast height
• Crown drip line
• Tree health
• Consideration for risk

For each tree identified as being preserved and/or recommended for removal, the valuation of the tree is needed. The town’s tree protection standards must be adhered to and approved in place prior to work starting. 

Our review will consider potential tree impacts related to the proposed grading and servicing. The review also considers potential impacts to boundary trees or those on adjacent properties. In some cases, there will be conditions attached to the DESP permit related to construction methods or oversight by an arborist related to excavation work. 

Tree replanting as compensation will be determined as part of the approval process. For more information, please visit Tree Protection During Construction Procedure page.

DESP agreement

In many cases, a DESP agreement will be required for stormwater management works. The agreement will be registered on title to ensure that the works that were relied upon as part of the approved plan are not removed without prior consideration and approval.

Securities and inspections

• Securities are collected at the beginning of the application. Approval based on final inspections are required prior to releasing site securities.
• Inspections are intended to confirm that work has been carried out in accordance with the approved plan.
• Before scheduling final inspections, a certification letter from the site surveyor is required that verifies they have been on site within 30 days of the dated letter and that the works have been carried out in accordance with the plan.
• Photos that demonstrate completion of works for all sides of the dwelling are to be attached to the certification letter.
• DESP fees include a maximum of two inspection visits, beyond which an additional administrative fee will be required.