This page explains what the rule means for Ontario farmers planning barn construction, livestock expansion, manure storage, or nutrient application.
What Is Minimum Distance Separation (MDS)?
Minimum Distance Separation (MDS) is an Ontario planning tool used to determine how far apart livestock facilities and neighbouring land uses must be. MDS is designed to reduce land use conflicts between agricultural operations and residential or other sensitive uses.
There are two types of MDS calculations: MDS I and MDS II. Both are critical when planning a new barn or expanding an existing livestock operation.
MDS I — Protecting New Development from Existing Farms
MDS I determines the minimum distance that a new non-agricultural development (such as a house, school, or commercial building) must be from an existing livestock barn or manure storage. In other words, MDS I protects new neighbours from existing farm operations.
Applies when new lots, buildings, or land uses are proposed near existing farms
Calculated based on the type and size of the existing livestock operation
Used by municipalities when reviewing severance, rezoning, or subdivision applications
MDS II — Protecting Neighbours from New or Expanding Farms
MDS II determines the minimum distance that a new or expanding livestock barn or manure storage must be from existing non-agricultural land uses. MDS II protects existing neighbours from new or expanding farm operations.
Applies when building a new barn or expanding an existing one
Applies when constructing new manure storage
Calculated based on the type and number of livestock, type of manure storage, and nearby land uses
Must be satisfied before a building permit can be issued
Why MDS Matters for Your Barn Build
If your proposed barn location doesn't meet MDS II requirements, you may need to relocate the building, reduce the herd size, or apply for a variance. Discovering MDS issues after construction has started can be extremely costly. Always check MDS before finalizing your site plan.
Key Factors That Influence MDS
Type of livestock (dairy, beef, poultry, swine, etc.)
Number of animals or nutrient units
Type of manure system (solid, liquid, etc.)
Proximity to neighbouring dwellings, churches, schools, or commercial areas
Whether the area is designated as a settlement or rural zone
Additional Factors in MDS
Neighbour distance — the closer the neighbouring non-farm use, the more challenging it can be to meet MDS requirements
Parcel size — smaller parcels may limit your options for barn placement to satisfy MDS II
Manure system impact — the type of manure system (solid, liquid, or mixed) directly affects MDS calculations and required setback distances
Quick Check: Does Your Site Meet MDS?
Use our preliminary screening tool to get a quick indication of whether your proposed barn site may meet MDS requirements.
Frequently Asked Questions
Do I need an NMS to build a barn in Ontario?
What are nutrient units and how does this relate to livestock?
When do I need both an NMS and an NMP?
How long does approval of a NMS or NMP take?