How to read construction phasing plans
Phasing plans show what gets built when, what stays occupied during construction, and how the site flows through each stage. Reading them requires understanding both the architectural drawings and the logistics sequence.
The Quick Answer
A phasing plan divides the project into sequential construction phases (Phase 1, 2, 3, etc.), showing for each phase: the work area, the occupied area, temporary construction (walls, fences, utilities), and the logistics routes. Phases are usually color-coded or hatched and keyed to a phase narrative in the specifications.
Phased projects have 20 to 40% more coordination issues than single-phase projects. Every phase change is a coordination moment, temporary walls come down, HVAC gets re-ducted, life safety systems get re-zoned. If the phasing plan is vague, the RFIs start on day one.
When You'll See a Phasing Plan
Phasing plans typically appear on projects with:
- Occupied buildings that remain in use during construction (hospitals, schools, offices, data centers)
- Campus-wide projects with sequenced building turnovers
- Multifamily projects built and occupied in blocks
- Infrastructure projects with phased traffic management
- Tenant improvements with move-sequence coordination
If a project has fewer than 4 phases, phasing may be shown on the architectural plans with hatches. Larger projects have a dedicated Phasing Plan drawing set with L-series (logistics) sheets.
Reading the Phasing Plan
Each phase drawing should show:
- Work area: What's being built or demolished in this phase
- Occupied area: What remains in operational use
- Temporary barriers: Construction walls (ICRA barriers in healthcare), dust containment, and smoke partitions
- Temporary egress: Modified egress paths when normal routes are blocked
- Logistics: Laydown areas, crane zones, parking, deliveries, hoisting
- Temporary utilities: Shared systems routing through active areas
- Duration and handoff: Target phase duration and tests/inspections required to complete
Related: temporary construction facilities for the support infrastructure.
ICRA and Infection Control in Healthcare Phasing
Healthcare phasing plans add Infection Control Risk Assessment (ICRA) classifications that dictate barrier construction, HEPA filtration, and pressurization requirements. The ICRA class (Type I-IV) and patient population risk group drive what the temporary wall has to do. For details on healthcare-specific requirements, see our healthcare construction compliance guide.
Life Safety in Phased Construction
Every phase must be reviewed by the AHJ for independent code compliance. The life safety plan for each phase must show:
- Active egress routes with rated paths
- Fire alarm zones that remain in service; zones temporarily disabled
- Sprinkler coverage in construction and occupied areas
- Smoke compartments preserved (hospital smoke compartments cannot be violated)
- Temporary exits and signage during each phase
Cross-reference egress design mistakes for common phase-egress errors.
Drawing Review Checklist for Phasing
- Does each phase show complete life safety compliance as an independent building?
- Are temporary walls shown with fire rating if they form egress enclosures?
- Do temporary utility routings not cross active occupant areas unless shielded?
- Does the fire alarm zone change drawing match the fire alarm phase drawings?
- Are the swing spaces for move-in and move-out shown with proper HVAC and finishes?
- Is there a phase-end punch list tied to owner acceptance for each phase?
Keep exploring
Related resources for navigating phased construction and logistics.
Barriers, utilities, and logistics support
ICRA and hospital phasing requirements
Phase egress and code compliance
Where phasing and logistics fit in a drawing set
Phase-appropriate structure and separation requirements
Where L-series and phasing drawings belong