When it comes to estimating drywall in shaft openings and core areas, even seasoned professionals can find themselves facing unexpected variables. These zones are inherently complex due to structural interruptions, service risers, elevator cores, and mechanical pathways—all of which present unique constraints. Getting these areas wrong during the estimating phase can result in budget overruns, delays, or last-minute design modifications. However, with the right methodology and data-enhanced workflows, estimators can approach these areas with the same confidence as standard partition walls.

Why Shaft and Core Areas Deserve Special Attention

Shaft openings and core areas are high-density, high-impact parts of a building. They often serve as vertical arteries for mechanical, electrical, and plumbing systems and frequently interface with multiple trades. These factors introduce considerable variability that standard estimating methods may overlook.

• Limited Accessibility: These areas may only be accessible during specific construction phases, limiting material transport and installation efficiency.
• Higher Labor Requirements: Due to confined space and safety requirements, these zones demand more skilled labor and extended installation times.
• More Complex Framing: Interfacing with steel supports, embeds, or curtain wall systems can increase framing complexity.
• Code Compliance: Shaft walls often have heightened fire-resistance requirements and require specialty assemblies or UL-listed systems.

Common Pitfalls in Estimating Shaft Walls

Despite being a smaller portion of total wall area, shafts and cores carry disproportionate risk in terms of cost volatility.

• Missed Elevation Changes: Vertical transitions are often undocumented, leading to undercounting of framing material.
• Assumed Continuity: Estimators may assume shaft wall layouts are continuous floor to floor, ignoring gaps for equipment or structure changes.
• Overlooking Double-Sided Conditions: Shafts that require finishes or framing on both interior and corridor sides are frequently misrepresented in takeoffs.

Techniques for Accurate Shaft Wall Estimating

To mitigate these issues, estimators should implement a structured approach to estimating these specialty areas:

• Separate shaft walls from general drywall quantities in your takeoff structure.
• Include labor multipliers for reduced access or lift constraints.
• Add allowances for shaft wall accessories—track stiffeners, fire caulk, and access doors.
• Request field-verified dimensions for MEP-intensive cores to avoid height discrepancies.

Data-Driven Intelligence for Specialty Areas

Using Active Estimating, estimators can quickly identify core zone materials and visualize them in 3D, ensuring that the complexity is captured in both quantity and labor. The tool's ability to track version changes and link conditions directly to BIM or 2D overlays ensures shaft cores are not just visualized—but accounted for with precision.

Handling Elevators, Riser Shafts, and Mechanical Chases

Each core type carries distinct considerations:

• Elevator Cores: Often require high impact-resistant boards or shaftliner products; double-check for fire-rated requirements spanning all levels.
• Riser Shafts: Pay attention to chase wall configurations and alternating board orientations for fire rating continuity.
• Mechanical Chases: Estimate for pipe sleeves, duct cutouts, and penetrations that complicate board application and layout.

Integrating Specialty Assemblies into Takeoffs

Estimators should utilize templates or assemblies that reflect the full complexity of shaft wall construction. A common mistake is using standard wall types and simply adjusting the area, but this can misrepresent labor hours and accessory needs. Instead, purpose-built assemblies in drywall estimating software will allow for correct framing types, board layers, and firestop materials from the outset.

Final Thoughts

Accurately estimating shaft openings and core areas doesn’t just improve budget confidence—it ensures the team avoids painful rework and last-minute procurement. By applying focused assemblies, referencing past project data, and leveraging modern platforms that capture complexity in context, these zones can be as predictable as any other scope area. Remember, it's the areas hidden behind access panels and walls that often decide whether your estimate holds up under pressure.

Contact Information:
Active Estimating
508 2nd Street, Suite 208
Davis, California 95616

Rich Schoener
richard@activeestimating.com
(877)