13.3 Feasibility Studies: Evaluating Project Feasibility & Due Diligence

The Go/No-Go Decision

The third feasibility task is the actual evaluation: can this project be built on this site, for this program, within this budget, and in compliance with these codes? If the answer is no, the designer's job is to say so before the client spends real money. A feasibility study that rubber-stamps a client's wish is professional malpractice. IDPX tests your ability to identify the single condition that kills the project—zoning, occupancy, structural capacity, energy compliance, or budget—and to name it in writing.

Zoning: The First Gate

Zoning is the first feasibility check because it determines whether the project is even allowed. Zoning governs:

• Use permissions — is the use permitted by right, by special permit, or prohibited outright?
• Setbacks — minimum distances from property lines that constrain buildable area
• Height and bulk — maximum stories and FAR (floor-area ratio) that cap total building area
• Parking — required spaces that consume site area and budget

If zoning prohibits the use or caps the area below the program need, no amount of design skill can fix it without a variance—a long, uncertain public process with neighbor input. Identifying a zoning conflict at feasibility lets the client choose a variance pursuit, a program reduction, or a different site before design money is spent.

Applicable Codes and Reference Standards

Once zoning allows the use, the building code governs how it must be built. The designer identifies the applicable codes and reference standards early:

• IBC (International Building Code) — occupancy classification, construction type, egress, fire protection
• Accessibility — ADA / ICC A117.1, plus state-specific accessibility codes that may exceed federal minimums
• Energy code — IECC or ASHRAE 90.1, depending on AHJ adoption; some jurisdictions have stretch codes
• Reference standards — NFPA 70 (National Electrical Code), ASHRAE 62.1 (ventilation for acceptable indoor air quality), ASTM E84 (flame spread and smoke development)

The feasibility study lists which codes apply and flags any that trigger upgrades the existing building cannot easily provide.

Building Types and Occupancy Types

Building type (use classification) and occupancy type drive the entire code path. A restaurant is Assembly (A-2); a typical office is Business (B); a hotel is Residential (R-1); a hospital is Institutional (I-2). The occupancy determines:

• Egress capacity and the minimum number of exits
• Fire-resistance ratings and required construction type
• Sprinkler requirements and fire-alarm thresholds
• Plumbing fixture counts and restroom distribution
• Accessibility route requirements and accessible element counts

Changing the use (e.g., office to assembly, or warehouse to retail) is the most common reason a renovation becomes infeasible. The existing building may not have the egress width, the sprinkler density, or the plumbing capacity to support the new occupancy, and upgrading those systems can exceed the project budget.

Energy Requirements

Energy code scope (IECC or ASHRAE 90.1) covers the building envelope, mechanical systems, service water heating, lighting power density, and controls. For renovations, the trigger depends on scope: a lighting-only renovation may need to meet only lighting power density limits, while a full fit-out must meet the full envelope-and-systems compliance path. Feasibility must scope which compliance path applies and whether the existing HVAC, envelope, and electrical systems can support it. An older building with single-pane glazing and a 30-year-old rooftop unit may fail envelope and mechanical compliance without upgrades that dwarf the tenant-improvement budget.

Existing Conditions Analysis

For renovation and adaptive reuse, the feasibility study hinges on existing conditions analysis—an assessment of the building as it actually stands, not as the drawings say it should:

• Structural capacity — can the floors carry the new live load? (file storage vs. offices vs. assembly seating)
• Hazardous materials — asbestos, lead paint, PCBs in old caulk; abatement costs can dominate a renovation budget
• MEP capacity — can existing HVAC, plumbing, and electrical service serve the new use, or must risers and panels be upsized?
• Envelope condition — roof leaks, façade deterioration, insulation levels that affect energy compliance
• Accessibility — is the entry, route, and restroom already accessible, or is a major upgrade required?

A warehouse converted to offices may look promising until the structural analysis shows the slab cannot support partition loads, or the existing plumbing cannot serve the new restroom count. Existing conditions analysis is the most common place where an adaptive reuse project dies.

Square Footage Requirements and Program Fit

Program fit tests whether the client's required spaces—offices, meeting rooms, circulation, restrooms, support—fit within the available area after code-required circulation and core space are deducted. A net-to-gross efficiency of 75% means a 10,000 sf floor yields only 7,500 sf of usable program. If the program needs 9,000 sf, the project is infeasible without more area, a variance for a small addition, or a smaller program. Program fit is a numbers exercise the designer must run before any layout work begins.

Funding Sources and Quality

Funding again affects feasibility: grant-funded projects may carry historic-preservation requirements that raise costs and constrain finishes; debt-financed projects may need lender sign-off on the pro forma before design can proceed. The feasibility study's cost estimate must reflect the funding source's restrictions, not just the designer's own scope assumptions.

Feasibility Study Deliverables

A feasibility study typically delivers four things:

1. Pro forma — projected cost, revenue, and return for the owner, reflecting funding source restrictions
2. Program fit — area needed versus area available, at a realistic net-to-gross ratio
3. Code compliance analysis — zoning, occupancy, accessibility, and energy findings with flagged upgrades
4. Cost estimate — order-of-magnitude, with a contingency appropriate to the unknowns (renovation contingency is higher than new construction)

Exam Scenario

An IDPX item may describe a proposed restaurant in an existing office building and ask the most critical feasibility concern. The change in occupancy type (B to A-2) triggers reconfigured egress, sprinkler upgrades, plumbing additions, and possibly construction-type upgrades; the existing building may not support them, making the use change the gating feasibility issue—not the paint color, the FF&E, or the brand consultant.