1.3 The Eight-Step EBD Process Framework

The Eight-Step EBD Process Framework

To move evidence-based design from an abstract academic concept into a reliable, repeatable project delivery methodology, The Center for Health Design (CHD) developed the Eight-Step EBD Process Framework.

CHD's study materials use this framework as the organizing spine for the EBD process, and its steps recur across all six domains of the current EDAC exam content outline. It guides multidisciplinary project teams through a disciplined scientific inquiry that begins long before the first sketch is drawn and continues long after the ribbon is cut.

---

Overview of the Eight Steps in Chronological Sequence

The eight steps follow a logical, scientific trajectory that parallels the standard architectural project delivery lifecycle:

Step 1: Define evidence-based goals and objectives
  │
Step 2: Find sources for relevant evidence
  │
Step 3: Critically interpret relevant evidence
  │
Step 4: Create and innovate EBD concepts
  │
Step 5: Develop a hypothesis
  │
Step 6: Collect baseline performance measures
  │
Step 7: Monitor implementation of design and construction
  │
Step 8: Measure post-occupancy performance results

---

Deep Dive: The Eight Steps

Step 1: Define Evidence-Based Goals and Objectives

• Typical Project Phase: Strategic Planning & Predesign.
• Core Activities: The client leadership and design team establish the foundational vision for the project, aligning physical investments with the healthcare organization's strategic mission.
• Defining Measurable Targets: High-level goals must be operationalized into measurable targets rather than vague aspirations. For example, instead of "improve patient safety," Step 1 defines: "Reduce patient fall injuries by 30%, eliminate hospital-acquired Clostridioides difficile transmissions, and decrease nurse turnover by 15% within the replacement medical-surgical pavilion."
• Stakeholder Engagement: Establish a multidisciplinary steering committee including executive sponsors, clinical leaders (CNO, CMO), staff nurses, facility managers, infection preventionists, and Patient and Family Advisory Councils (PFACs).

Step 2: Find Sources for Relevant Evidence

• Typical Project Phase: Predesign & Early Programming.
• Core Activities: The team conducts a rigorous search to identify existing knowledge that can inform the project's defined goals.
• External Evidence Sources: Academic, peer-reviewed literature in specialized journals such as Health Environments Research & Design Journal (HERD), The Lancet, New England Journal of Medicine, Journal of Healthcare Engineering, and databases like PubMed, Cochrane Library, and CHD's Knowledge Repository.
• Internal Evidence Sources: Institutional operational data, including historical incident reports, medication error logs, patient fall incident data, HCAHPS patient satisfaction scores, employee exit interviews, and facility maintenance work orders.

Step 3: Critically Interpret Relevant Evidence

• Typical Project Phase: Programming & Early Schematic Design (SD).
• Core Activities: Raw research cannot simply be inserted into a design; it must be critically appraised for methodological rigor, validity, and applicability.
• Methodological Evaluation: The team assesses whether external studies utilized adequate sample sizes, controlled for confounding variables, and possessed internal and external validity.
• Contextual Translation: The team determines whether findings from a major academic medical center apply to their community hospital, taking into account differences in patient acuity, staffing models, and climate.
• Developing Design Guidelines: Synthesizing validated evidence into actionable design criteria and functional space programs.

Step 4: Create and Innovate EBD Concepts

• Typical Project Phase: Schematic Design (SD) & Design Development (DD).
• Core Activities: Multidisciplinary teams translate interpreted evidence into spatial, architectural, interior, and technological concepts.
• Evidence-Driven Innovation: Rather than copying past templates, teams design novel physical solutions aimed directly at achieving the Step 1 goals (e.g., decentralized nurse charting alcoves with direct sightlines to patient headwalls, circadian lighting systems, or standardized same-handed room layouts).
• Prototyping & Simulation: Testing concepts prior to construction using iterative simulation tools: digital 3D/BIM walkthroughs, virtual reality (VR) spatial modeling, and full-scale physical mock-up rooms (ranging from low-fidelity cardboard mock-ups to high-fidelity operational test environments). Frontline nurses and physicians perform simulated clinical tasks (e.g., patient resuscitation, bed-to-toilet transfers) to identify ergonomic bottlenecks and safety hazards.

Step 5: Develop a Hypothesis

• Typical Project Phase: Design Development (DD) & Early Construction Documents (CD).
• Core Activities: The team articulates explicit, testable, and falsifiable propositions that connect specific design innovations to expected clinical, operational, or economic outcomes.
• The "If-Then" Structure: A rigorous EBD hypothesis must clearly specify the independent variable (the design intervention), the dependent variable (the clinical/operational outcome), the target metric, and the measurement timeframe.

Formula for an EBD Hypothesis: "IF [specific design intervention is implemented], THEN [specific measurable outcome will occur], as measured by [specific performance metric] over [defined post-occupancy timeframe]."

Practical Example: "IF we implement decentralized nursing stations outside every two patient rooms with direct window sightlines to the patient headwall and decentralized medication dispensing cabinets, THEN average nurse walking travel distance will decrease by 25% and patient call light response times will decrease by 35% over a 12-month post-occupancy period compared to baseline."

Step 6: Collect Baseline Performance Measures

• Typical Project Phase: Construction Documents (CD) & Construction Administration (CA).
• Core Activities: The team collects pre-occupancy baseline metrics in the existing facility (or comparable control units) before construction is completed and before relocation occurs.
• The Scientific Reference Point: Without baseline measures, a post-occupancy evaluation has no comparative benchmark. If a hospital measures a fall rate of 2.1 falls per 1,000 patient days after moving into a new tower, it cannot claim the design succeeded unless it documented the baseline rate in the old facility using the identical measurement protocol.
• Common Baseline Metrics: Ambient acoustic decibel levels (dBA Leq, L10, Lmax), nurse travel steps per 12-hour shift (via pedometers/RFID tracking), surface microbial bioburden, patient sleep interruptions, and medication preparation distraction counts.

Step 7: Monitor Implementation of Design and Construction

• Typical Project Phase: Construction Documents (CD), Procurement, & Construction Administration (CA).
• Core Activities: The team actively monitors construction to ensure that the evidence-based design intent is preserved through detailed specifications, contractor bidding, procurement, shop drawing reviews, and field inspections.
• Guarding Against Value Engineering (VE): In traditional construction, when budgets exceed estimates, contractors propose indiscriminate cost reductions. Under Step 7, the EBD team defends evidence-based features by presenting empirical research and business case calculations. Example: If a contractor proposes replacing high-performance acoustic ceiling tiles (Noise Reduction Coefficient [NRC] 0.90) with cheaper standard tiles (NRC 0.55), the EBD team goes back to the goals, hypotheses, and business case: which outcome was the feature meant to protect (for example, sleep and speech privacy), how strong is that evidence, and does the projected return still hold without it?

Step 8: Measure Post-Occupancy Performance Results

• Typical Project Phase: Post-Occupancy Evaluation (POE), no sooner than about six months after occupancy.
• Core Activities: After building activation, the team systematically gathers post-occupancy performance data to evaluate actual outcomes against the hypotheses formulated in Step 5.
• Operational Stabilization: POE data collection should not occur immediately upon ribbon-cutting. CHD materials, including its clinic POE toolkit, advise waiting at least six months after occupancy so users learn to use the space consistently and move-in biases settle; many teams then collect data over a longer period to capture seasonal variation.
• Data Triangulation: The team gathers quantitative operational metrics (infection rates, fall rates, travel steps) alongside qualitative feedback (occupant satisfaction surveys, focus groups).
• Closing the Loop (Knowledge Sharing): The EBD process is not complete until findings are shared. Teams document both successes and unexpected negative outcomes in peer-reviewed journals (like HERD), conference proceedings, and institutional case studies to advance the global healthcare design community.

---

Mapping the 8 Steps to Typical Project Phases

Evidence-Based Design does not replace standard architectural delivery; it enriches each phase. CHD study materials note that the EBD process can be incorporated at any stage of a building project, so treat the mapping below as a typical pattern rather than a fixed rule:

---

The Fluid and Iterative Nature of the Process

While presented chronologically for conceptual clarity, the Eight-Step EBD Process is fluid and iterative:

• In Step 4 (Create Concepts), rapid prototyping may reveal unexpected ergonomic or spatial constraints, prompting the team to return to Step 2 and Step 3 to search for additional evidence regarding alternate layouts.
• In Step 5 (Develop Hypotheses), refining the measurable metrics may lead the team to adjust the initial Step 1 operational goals.
• Step 8 (Post-Occupancy Evaluation) frequently reveals new operational questions, providing the baseline data and evidence foundation for the organization's next capital renovation.

[!CAUTION]

EXAM TRAP: Step 1 Goal vs. Step 5 Hypothesis

Scenario questions often hinge on distinguishing a Step 1 Goal from a Step 5 Hypothesis:

• Step 1 Goal: Establishes the organizational vision and desired outcome ("We want to reduce hospital-acquired pressure injuries by 30%"). It does not specify the precise architectural intervention or the "if-then" causal mechanism.
• Step 5 Hypothesis: Articulates the exact, testable causal mechanism linking a physical design intervention to the outcome ("IF we install ceiling lifts with continuous tracking to the en-suite toilet in 100% of rooms, THEN pressure injuries will decrease by 30% over 12 months").

Confusing a strategic goal with a testable hypothesis is an easy mistake to make under time pressure.