What is a "Change of Use"?

A change of use is often misunderstood as a simple paperwork exercise or a “quick life safety drawing.” In reality, it’s a code-driven evaluation of whether a building can safely support a new way of being occupied. What may start as a life safety plan can quickly cascade into impacts on egress, fire ratings, accessibility, plumbing fixture counts, fire alarm, sprinkler systems, and MEP coordination. Because each decision affects another, change of use reviews tend to have a domino effect; making early, thoughtful planning essential to avoid delays, redesigns, and unexpected costs. 

What AHJs Actually Expect - Why a Change of Use Matters

A change of use (or occupancy) is more than a tenant change. When the intended use of a space changes, the code assumptions change—including how many people occupy the space, how they exit, how fire spreads, and which systems are required to protect life.

Even when an Authority Having Jurisdiction (AHJ) requests a “life safety plan only,” that request typically represents a code-based analysis, not a simplified drawing.

The Change of Use Process (High Level)

• Confirm the proposed use is permitted
• Verify zoning or land-use compliance for the proposed occupancy.
• Some jurisdictions require zoning sign-off before building permits are issued.
• Submit for building permit
• A change of use usually requires a building permit and plan review.
• Architectural, MEP, and fire protection disciplines are commonly reviewed together.

Plan review and comments

• The AHJ evaluates whether the existing building safely supports the new use.
• Comments often focus on life safety, egress, fire protection, and system adequacy.
• Inspections and Certificate of Occupancy
• Occupancy is typically prohibited until approvals and inspections are complete.
• A new or updated Certificate of Occupancy may be required.

What a “Life Safety Plan” Really Includes

A life safety plan is a code summary and diagram that demonstrates how occupants can safely exit the building and how the building protects life in an emergency.

It typically includes:

• Occupancy & Load
• Occupancy classification(s)
• Mixed-use approach (separated vs. non-separated, if applicable)
• Occupant load calculations by space
• Fire area identification
• Egress & Exiting
• Exit locations and exit signage
• Exit access travel distances
• Common path of travel
• Dead-end corridor lengths
• Exit widths and exit capacity calculations
• Egress paths clearly diagrammed and dimensioned
• Fire & Life Safety Features
• Fire-rated walls, corridors, and separations
• Fire and smoke barriers (where applicable)

Door hardware types:

• Panic hardware
• Delayed egress locking
• Electromagnetic locks
• Door hold-open devices
• Emergency escape or rescue openings (where required)
• Life Safety Systems (Identified & Coordinated)
• Emergency lighting
• Exit lighting
• Fire alarm systems
• Smoke detection
• Carbon monoxide detection (if applicable)

What “Life Safety Only” Means by Discipline

Architectural Scope

Even when labeled “life safety only,” architectural review typically includes:

• Code analysis supporting the new occupancy
• Rated construction and separation logic
• Egress geometry and calculations
• Door schedules and hardware coordination
• Accessibility impacts triggered by the change of use

MEP Scope (Often Overlooked)

Life safety relies on MEP systems functioning correctly:

• Electrical
• Emergency and egress lighting
• Power to life safety systems
• Mechanical
• Ventilation suitability for the new use
• Fire/smoke damper coordination
• Rated wall continuity on mechanical plans
• Fixture count adjustments due to occupancy changes
• Venting and interceptor requirements where applicable
• Fire Protection Scope

A change of use may trigger:

• Sprinkler system modifications or extensions
• Updated fire area boundaries
• Fire alarm device additions or reconfiguration
• Coordination between fire alarm and door hardware

Key Takeaway

When an AHJ asks for a “life safety plan,” they are not asking for less work—they are asking for proof that the building safely supports the new use.

A compliant life safety plan:

• Is code-driven
• Is coordinated across disciplines
• Reflects the realities of the proposed occupancy
• Anticipates AHJ review questions before they are asked