CMAR is the dominant model for complex acute-care work largely because of what it lets the team solve before the GMP is set — the operational, regulatory, and logistics realities of building in and around a live hospital. This article covers the healthcare-specific work that makes CMAR earn its premium: multi-phase construction sequencing, early procurement of long-lead medical and infrastructure systems, and the disciplines required to build on an occupied campus without compromising patient care or accreditation.

These considerations are why owners pay for preconstruction rather than the mechanics of the model itself (covered in the model-overview and GMP siblings) or the selection process (covered in the procurement sibling). The focus here is the healthcare-domain content a CM-at-Risk must master to deliver a hospital project safely and on schedule.

Phasing and sequencing are a core CMAR deliverable, not an afterthought

Acute-care projects almost never proceed as a single linear build. Renovations of occupied departments, additions that tie into running utilities, and tower projects that must keep an emergency department open all require the work to be broken into phases — discrete, separately commissioned segments of construction that allow the hospital to keep operating while space is taken out of service in a controlled sequence. CMAR's early-CM involvement exists in large part to develop, price, and de-risk this phasing during preconstruction.

A healthcare phasing plan typically resolves:

• Decant and swing space. Before a department can be renovated, its function must move somewhere. The CM and design team identify temporary ("swing") locations, or a sequence where Phase 1 builds the new space that lets Phase 2 vacate the old. Swing space for clinical functions must itself meet code (FGI, ASHRAE 170, NFPA 99/101) for the use it temporarily houses.
• Tie-in windows. Connections to live medical gas, normal and essential electrical power, domestic and chilled water, fire alarm (NFPA 72), and HVAC must happen during planned outages — often nights, weekends, or scheduled low-census periods coordinated with clinical leadership. Each tie-in is sequenced and its duration negotiated against operational impact.
• Maintenance of egress and life safety. Every phase must preserve compliant means of egress, fire/smoke compartmentation, and fire-protection coverage for occupied areas (IBC, NFPA 101 Life Safety Code). Temporary conditions are documented and approved rather than improvised.
• Logistics and the construction "footprint." Material delivery, crane picks, hoisting, debris removal, and worker circulation must be routed to avoid patient, visitor, and staff paths — and to keep ambulance, emergency, loading-dock, and helipad access continuously open.

Because the GMP is built on this phasing plan, CMAR lets the owner see and challenge the sequence before committing price and schedule. A poorly phased hospital project does not just cost more — it can force a department closure, divert patients, or trigger an accreditation finding. Preconstruction is where those failure modes are designed out.

ICRA and interim life safety drive the build sequence in occupied facilities

Two healthcare-specific risk frameworks shape nearly every construction decision on an active campus, and a competent CM-at-Risk prices and plans them from day one rather than discovering them in the field.

Infection Control Risk Assessment (ICRA). Construction generates dust, disrupts airflow, and can mobilize pathogens (notably Aspergillus) that are lethal to immunocompromised patients. The ICRA process — referenced in the FGI Guidelines and required in practice by The Joint Commission (TJC), DNV, and CMS Conditions of Participation (CoP) surveyors — matches the type of construction activity against the risk level of adjacent patient populations to determine required precautions. Typical controls scale up by class and include:

• Sealed dust barriers and anterooms; sticky/walk-off mats.
• Negative-pressure containment of the work zone relative to occupied areas, with HEPA-filtered exhaust and continuous pressure monitoring.
• Sealing or relocating return-air pathways; protecting or isolating affected HVAC.
• Controlled debris transport in covered containers along designated routes.
• Terminal cleaning and air clearance before a barrier comes down.

ICRA classifications are documented, approved by the hospital's infection prevention team, and inspected throughout the job. They directly constrain how and when work proceeds, which is why they belong in the phasing plan and the estimate, not in a field add later.

Interim Life Safety Measures (ILSM). When construction temporarily degrades a built-in life-safety feature — a blocked exit, an impaired sprinkler zone, a breached smoke barrier, a disabled fire-alarm device — the facility must implement compensating measures: additional fire watches, temporary alarms or signage, extra extinguishers, enhanced surveillance, training, and limits on smoking and hot work. ILSM is assessed against the NFPA 101 Life Safety Code and enforced by accreditors. The CM coordinates ILSM with the hospital's safety/facilities staff so that each phase's temporary conditions stay continuously compliant.