When Does an Expansion Trigger Approvals?
Expanding a livestock operation in Ontario — whether you're adding animals, building a new barn, or increasing manure storage — can trigger several regulatory requirements. Understanding what triggers these requirements early in the planning process can save you significant time and money.
Common Expansion Triggers
Building a new livestock barn or expanding an existing one
Increasing the number of animals on your farm
Constructing new or expanded manure storage
Exceeding 5 nutrient units (may trigger NMS requirement)
Exceeding 300 nutrient units (may trigger NMP requirement)
Changes that increase nutrient generation on your property
Common Expansion Triggers
When you expand your livestock operation, the Minimum Distance Separation (MDS II) calculations must be reviewed. Increasing your herd size or building in a new location changes the required separation distances from neighbouring properties.
Even if your existing barn meets MDS, an expansion may change the MDS II requirement. Always recalculate MDS before proceeding with any expansion.
NMS and NMP Requirements
Most livestock expansions will require a Nutrient Management Strategy (NMS). If your operation exceeds 300 nutrient units after expansion, you will also need a Nutrient Management Plan (NMP). Both documents must be approved before construction can begin.
Planning Your Expansion
Start the planning process early — approvals take weeks to months
Get MDS calculations done before finalizing your site plan
Determine your nutrient unit count to understand which plans are needed
Confirm manure storage capacity meets the expanded operation
Work with a qualified nutrient management consultant
Tools to Plan Your Expansion
Can I Build a Barn Here?
Check whether a proposed barn location may be constrained by MDS, setbacks, or nearby land uses.
Use the Advanced Preliminary MDS Screening Tool
Estimate detailed MDS-related setback planning for livestock barns and manure storage.
Calculate Nutrient Units
Estimate livestock nutrient units to help determine whether NMS or NMP requirements may be triggered.
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?