2.1 Integrative Process Philosophy and Workflow

Why Integrative Process Matters

LEED's first credit category — Integrative Process (IP) — is small in points (only 1 point in BD+C) but enormous in influence. Every other category in the rating system performs better when the project team adopts IP early. The exam tests IP as both a philosophy and a workflow, so you need to understand the why before you memorize the requirements.

Traditional design is linear: the architect designs, hands drawings to the mechanical engineer, who hands them to the electrical engineer, who hands them to the contractor. Each discipline optimizes its own scope. The result is a collection of locally optimized systems that fight each other globally — oversized HVAC, glare from poorly placed glazing, plug loads no one budgeted for. LEED calls this the 'throw it over the wall' approach, and IP exists to eliminate it.

Quick Answer: The Integrative Process is a collaborative, multi-disciplinary design workflow that begins at concept design and continues through occupancy. It is structured as Discovery, Implementation, and Performance Feedback, and it is documented through the Owner's Project Requirements (OPR) and Basis of Design (BOD).

The Three IP Phases

Think of IP as a loop rather than a checklist. Each phase feeds the next, and lessons from occupancy feed back into future projects.

The Discovery phase is where most of the IP credit's documentation is generated. Discovery is the time to ask open questions — what are we actually trying to accomplish, what does the site want to do, what does the climate reward — before the team commits to a design parti.

The Charrette

A design charrette is an intensive, time-boxed working session that brings the full project team together early in Discovery. The classic charrette runs one to three days and includes the owner, architect, MEP engineers, civil engineer, landscape architect, contractor, commissioning agent, and future occupants (or their representatives). The charrette is not a status meeting — it is a structured collaboration designed to surface trade-offs and synergies before documents are drawn.

A strong charrette produces three deliverables:

• A draft Owner's Project Requirements (OPR) capturing the owner's sustainability, performance, and cost goals
• A preliminary list of synergies to investigate (for example, daylighting → lighting → cooling → mechanical sizing)
• A shared scorecard showing which LEED credits the team will pursue and who owns each

OPR and BOD: The Anchor Documents

Two documents thread through IP from Discovery into commissioning:

• Owner's Project Requirements (OPR) — A written statement from the owner describing functional, performance, occupant, sustainability, and budget goals. The OPR is owner-authored (often with consultant help) and updated as goals evolve.
• Basis of Design (BOD) — A written statement from the design team describing the assumptions, calculations, narratives, and product selections used to meet the OPR.

The commissioning agent (CxA) uses the OPR and BOD throughout design review and during functional testing. If a system is installed but does not perform against the OPR, commissioning has failed regardless of how cleanly the equipment was installed. Expect the exam to test the relationship between OPR, BOD, and the commissioning process.

Whole-Systems Thinking and Synergies

The single most important IP concept on the exam is synergies — design decisions that create cascading benefits across systems. The canonical example:

1. Optimize building orientation and massing so the long axis faces east-west
2. Tune glazing and shading to maximize daylight while controlling glare and solar gain
3. Lower electric lighting power density because daylight does the work
4. Lower internal heat gains from lighting, which shrinks cooling loads
5. Smaller cooling loads allow smaller HVAC equipment and a smaller mechanical room
6. Smaller equipment and rooms reduce first cost — which can fund higher-performance envelope assemblies

This is the loop IP is designed to surface. A linear process would have specified HVAC before the daylighting strategy was settled, locking in oversized equipment.

Who Is on an IP Team?

IP demands a wider tent than traditional design. At minimum, the IP team includes:

• Owner (and owner's representative if applicable)
• Architect / lead designer
• Mechanical, electrical, and plumbing (MEP) engineers
• Civil engineer for site, stormwater, and infrastructure
• Landscape architect
• Structural engineer
• General contractor (early, ideally during Discovery)
• Commissioning agent (CxA) — required separately under EA prerequisites
• Occupants or facility manager — the people who will actually run the building

Bringing the contractor and CxA in during Discovery is the single biggest cultural shift IP asks of traditional teams. Constructability and commissionability shape design — they should not be afterthoughts.

Linear vs Integrative: The Cost Curve

A second concept the exam loves: the MacLeamy curve. Effort spent early in design (Discovery and schematic) has dramatically more influence on cost and performance than effort spent late. IP shifts the effort curve to the left — more decisions made when the cost of changes is lowest. By the time construction documents are issued, the building's energy performance, water performance, and material strategies should already be locked in.

Practical Implication for the Exam

When a question describes a team conducting an energy analysis after construction documents are complete, or a team adding the commissioning agent during construction, the right answer is almost always that the team waited too long. IP requires these activities before schematic design is complete.