Grading Plan Requirements in Ontario and GTA Municipalities for Building Permits

City of Mississauga

Mississauga has one of the most comprehensive grading plan review processes in the Greater Toronto Area. Grading plans are reviewed by the City’s engineering staff to ensure that proposed construction does not create drainage problems, increase ponding, adversely affect neighbouring properties, or negatively impact the municipal storm drainage system.

Depending on the nature of the project, a grading plan prepared by a Professional Engineer (P.Eng.) or Ontario Land Surveyor (OLS), stamped, dated, and signed, may be required as part of a building permit application or other development-related approval process.

The grading plan should clearly identify existing and proposed grades, drainage patterns, swales, retaining walls, driveway elevations, building elevations, drainage discharge locations, and any other features necessary to demonstrate positive drainage throughout the site.

Additional requirements may apply depending on the size of the project, site constraints, proposed retaining walls, proximity to municipal infrastructure, and whether the property is subject to other development approvals.

City of Brampton

Brampton requires a grading plan for all new custom homes, ground-floor additions that affect site drainage, walk-out basements, new doors at grade, and in-ground pools. Plans must be stamped and signed by a Professional Engineer licensed in Ontario.

The Grading Plan Terms of Reference (May 2026), published by Brampton’s Planning & Development Department, sets out specific requirements for content, format, and standard notes that must appear on every grading plan submission.

For projects involving more than 1,000 m³ of fill within a 12-month period, or where the site elevation significantly changes, a Site Alteration Permit under By-law 119-2024 (enacted July 10, 2024) is required in addition to the building permit. A Lot Grading Certificate is required upon completion, issued by the Consultant Engineer confirming that grading and sodding conform to the approved overall grading plan.

City of Vaughan

Vaughan’s Development Engineering Department reviews all grading plans to ensure they protect neighbouring properties and municipal infrastructure. Plans must be stamped by a P.Eng. or OLS when required thresholds are met. Vaughan uses the ePlans online portal for permit submissions. Walk-out basements and new entrances at grade require a grading permit in addition to the building permit.

In City of Vaughan, grading permits to be issued by the Development Engineering Department before applying for the associated building permit. Refer to Residential Grading Permit Application Requirements for details. Drawings prepared for grading permits must contain standard Lot Grading Notes.

The following table specifies when a grading permit or engineering permit is required in City of Vaughan.

* Accessory structures include detached garages, sheds, cabanas, and similar outbuildings.

City of Markham

Markham uses a specific Residential (Infill) Grading and Servicing (RGS) application process. An RGS application must be submitted and accepted by the City before a building permit application is made for:

• Type I: All new detached infill residential construction regardless of size
• Type II: Residential additions impacting 50 m² or more of existing ground surface

For multi-unit residential buildings (3 or more units) and all non-residential developments, a licensed Professional Engineer is specifically required. No wood retaining walls are permitted — walls must be constructed of concrete, stone blocks, or other approved material. Front yard catch basins are not permitted in Markham’s lot grading specifications. A Lot Grading Undertaking Deposit is held by the City and released only after the engineer issues a final grading certification upon completion.

The City of Markham has published Lot Grading Requirements for Subdivision Grading Plans as well as individual lot grading plans (Siting & Grading Plans) including the following items:

• A minimum of 0.6 m undisturbed strip shall be required where abutting existing lots
• Minimum and maximum yard slopes and swales: 2% and 5%
• Minimum and maximum driveway slope: 2% and 8%
• Minimum and maximum side yard swale depth: 150 mm and 250 mm
• Minimum vertical distance between the highest lot grade adjacent to the house and the top of the foundation wall: 0.15 m
• Retaining walls are generally required where 3(H) : 1(V) slope cannot be achieved
• Details of retaining walls over 0.90 m shall be submitted with the Grading Plans and stamped
  by a Professional Structural Engineer
• A 1.5 m high fence shall be required where a retaining wall height exceeds 0.9 m.

City of Richmond Hill

Richmond Hill requires a grading plan for new residential construction, infill development, additions affecting drainage, pool installations, and any site alteration. A Site Alteration Permit is required for any work that alters the land’s surface, including grading, excavation, filling, or soil removal.

Key Richmond Hill-specific requirements include:

• A Registered P.Eng. or OLS must confirm all footing formwork elevations and setbacks before concrete is placed
• Retaining walls: P.Eng. design required regardless of height; no wood retaining walls permitted
• Rear lot catch basin easements must be minimum 3.0 m wide, centered on side lot lines
• All rainwater leaders must discharge onto splash pads at ground level
• Written consent from the City Arborist is required before removing any trees affecting the grading area
• Existing boundary elevations along the site perimeter must remain undisturbed where specified on the approved plan

Smaller York Region Municipalities

The Towns of Aurora, Newmarket, Whitchurch-Stouffville, East Gwillimbury, Georgina, Bradford West Gwillimbury, and the Township of King all require grading plans for new residential construction and significant additions. Requirements generally mirror those of the larger York Region municipalities, with plans to be prepared and stamped by a P.Eng. or OLS. Pre-consultation with the local building or engineering department is recommended before submitting any grading-related application.

Durham Region: Pickering, Ajax, Whitby, Oshawa, and Clarington

All Durham Region municipalities require grading plans for new residential construction and for any project that alters existing drainage patterns. Plans must be prepared and stamped by a Professional Engineer (P.Eng.) or Licensed Ontario Land Surveyor (OLS).

Oshawa’s Engineering Design Criteria Manual (January 2025) sets out detailed civil drawing requirements, including engineer’s stamps on all civil drawings, basement floor elevations, roof-water leader outfall locations, and erosion control detailing. For subdivision-scale proposals of 0.4 ha or greater in Oshawa, storm sewer design calculations are also required.

Requirements for Pickering, Ajax, and Whitby are confirmed on a project-by-project basis with each municipality’s Building Services department, as their zoning by-laws are not fully consolidated online.

City of Burlington

In Burlington, anyone applying for a building permit for a single detached, duplex, or semi-detached dwelling used solely for residential purposes must apply for a Grading and Drainage Clearance Certificate as part of the building permit process. Plans must be stamped and certified by a Professional Engineer.

Where low-impact development (LID) features are proposed, a Stormwater Management Brief (also stamped by a P.Eng.) is required. Post-construction, a P.Eng. must provide as-built certification for LID components. Erosion and sediment control measures must be installed before any construction commences. A Drainage System Appurtenances Agreement must be executed and registered if required, and a final City inspection must be arranged before final approval is granted and securities are released.

Town of Oakville

Oakville requires grading plans for new residential construction, ground-floor additions, pool installations, and any project affecting site drainage, consistent with Halton Region engineering standards. Plans must be prepared and stamped by a P.Eng. or OLS. Properties near Conservation Halton regulated areas — including floodplains, wetlands, and river valleys — may require a separate Conservation Halton permit under Ontario Regulation 41/24 in addition to municipal grading approvals.

Town of Milton and Town of Halton Hills

Milton and Halton Hills require grading plans for new residential construction and for additions or site alterations that affect drainage patterns, consistent with Halton Region engineering standards. Halton Hills specifically requires that grading submissions include existing and proposed grades along the property line, the volume of material to be excavated in cubic metres, and a sediment and erosion control plan. Erosion control measures must be installed prior to any works commencing on site.

Grading Design Standards Common Across GTA Municipalities

While each municipality has its own submission format and review process, the following design standards are broadly consistent across the GTA:

The Lot Grading Certificate: What Happens After Construction

Obtaining a building permit is not the end of the grading process. After construction is complete and final grades are established and sodded, the licensed professional who designed the grading plan is typically required to visit the site and issue a Lot Grading Certificate (also called a Grading Completion Certificate or As-Built Certification) to the municipality. This certificate:

• Confirms that constructed grades match the approved grading plan
• Is a prerequisite for the final occupancy permit in most municipalities
• Triggers the release of any lot grading security deposit or financial assurance held by the City
• Confirms assumption of the subdivision grading in new subdivision contexts

Conservation Authority Requirements

Properties located within or adjacent to regulated areas — including floodplains, wetlands, river valleys, and the Lake Ontario shoreline — may require a permit from the applicable Conservation Authority in addition to municipal grading approvals. The relevant Conservation Authorities in the GTA are:

Any proposed grading, filling, or site alteration within a regulated area requires a permit under Ontario Regulation 41/24. Pre-consultation with the applicable Conservation Authority before preparing grading plans for affected properties is strongly recommended.

Common Reasons Grading Plans Are Rejected or Receive Review Comments

Even a professionally prepared grading plan can receive review comments from the municipality. The most frequent causes include:

• Drainage directed toward a neighbouring property rather than away from it
• Insufficient positive slope (less than 2%) away from the building foundation
• Missing top-of-foundation or finished floor elevation
• Conflict with an existing approved subdivision grading plan or master lot grading plan
• No swale shown along property lines where required by the municipality
• Sump pump or downspout discharge routed onto adjacent property or to the street
• Missing benchmark reference or wrong geodetic datum (particularly in Mississauga)
• Plan not drawn to the required scale
• Retaining walls shown without required structural details or P.Eng. stamp
• Inconsistency between the grading plan and the architectural or structural drawings submitted with the permit package

Coordinating the grading plan with all other permit drawings from the beginning of the project is the most effective way to minimize review comments and reduce overall permit timelines.

Frequently Asked Questions

Do I need a grading plan for a building permit in Ontario?

Many municipalities require a grading plan for new houses, additions, pools, retaining walls, and projects that alter drainage patterns.

Who can prepare a grading plan in Ontario?

Depending on municipal requirements, a Professional Engineer (P.Eng.) or Ontario Land Surveyor (OLS) may be required.

How much does a grading plan cost in Ontario?

The cost depends on the municipality, property size, available survey information, and the complexity of the project.