HVAC Estimating for a 280-Bed Hospital by F&K

## Project Context This walkthrough demonstrates a typical estimating methodology for a new-build acute care hospital in a high-seismic state. The example scenario is a 280-bed, approximately 320,000 SF facility subject to OSHPD (Office of Statewide Health Planning and Development) oversight and FGI (Facility Guidelines Institute) standards. Healthcare construction is the most technically demanding environment in the estimating profession. The dual regulatory framework — state OSHPD review and federal FGI standards — creates cost drivers that do not exist in commercial office or institutional work. ## Estimating Objectives A typical engagement involves validating or re-estimating the mechanical scope to identify scope gaps before the project goes to bid. Common objectives include: - Identifying OSHPD-specific seismic bracing requirements - Building an ASHRAE 170 ventilation compliance matrix - Quantifying ICRA (Infection Control Risk Assessment) compliance costs - Pricing NFPA 99 medical gas piping and certification testing ## Typical Challenges ### 1. OSHPD Seismic Bracing — A Common Miss In California's high-seismic zones, all mechanical and plumbing systems in essential facilities must comply with Title 24 Part 2 and ASCE 7-22 for seismic restraint. This is not optional. A typical seismic bracing package for a hospital of this size includes: - Longitudinal and transverse sway bracing on all ductwork runs exceeding 12 inches wide, using 12-gauge galvanized trapeze hangers per SMACNA standards - Seismic isolation mounts under rooftop AHUs (typically 10–15 units ranging from 30,000 to 80,000 CFM) - Flexible connector assemblies at all duct-to-equipment connections, minimum 12 inches per SMACNA Chapter 3 This line item alone can represent several hundred thousand dollars — and it is frequently missing from estimates that rely on national RSMeans data without California-specific adjustments. ### 2. ASHRAE 170 Ventilation Compliance Matrix ASHRAE 170 mandates specific minimum air change rates, pressurization relationships, and filtration levels for every room type in a licensed healthcare facility. Unlike commercial HVAC, you cannot calculate required CFM by square footage alone. A typical compliance matrix covers hundreds of unique rooms. Example room classifications: | Room Classification | Min ACH (Outside Air) | Min ACH (Total) | Pressure Rel. | Filtration | |:---|:---:|:---:|:---:|:---:| | Operating Room | 4 | 20 | Positive | HEPA | | Isolation Room (Neg.) | 2 | 12 | Negative | HEPA | | Patient Room | 2 | 6 | – | MERV-14 | | Soiled Utility | 0 | 10 | Negative | MERV-14 | | Pharmacy | 0 | 4 | Positive | MERV-14 | HEPA filtration requirements for operating rooms and isolation rooms trigger dedicated terminal units, fan-powered filtration boxes, and ULPA-grade exhaust systems — equipment costs that may not be reflected in a standard MERV-14 specification. ### 3. ICRA Compliance for Mechanical Systems When an occupied wing remains operational adjacent to active construction, ICRA Level IV requirements apply. For mechanical systems, this typically includes: - Sealing and abandoning return air griles within 200 LF of the ICRA barrier - Establishing temporary negative pressure exhaust using HEPA-filtered negative air machines - Sealing all new ductwork openings with 6-mil poly immediately after fabrication - Installing disposable pre-filters (MERV-8) on intake for HVAC units serving the occupied wing This compliance package is often priced as a separate Division 01 line item — and is frequently missed by non-specialist estimators. ### 4. NFPA 99 Medical Gas Piping Medical gas systems (oxygen, vacuum, medical air, nitrous oxide, nitrogen) are among the most labor-intensive line items in a hospital estimate. A typical quantification includes: - Type L copper pipe per NFPA 99 5.1.3.5 (brazed joints only, no press fittings) - Zone Valve Boxes (ZVBs) — one per zone, per gas type, per floor - Master Alarm Panels (MAPs) at nursing stations per NFPA 99 5.1.4 - Third-party ASSE 6010 certified verification testing per NFPA 99 5.1.12 The verification testing requirement is commonly omitted from estimates prepared by non-specialist estimators. ## Applicable Codes & Standards - **ASHRAE 170-2021** — Healthcare ventilation design - **NFPA 99** — Health Care Facilities Code (medical gas systems) - **OSHPD / Title 24 Part 2** — California hospital structural and mechanical oversight - **ASCE 7-22** — Seismic design requirements - **SMACNA** — HVAC duct construction standards and seismic bracing - **FGI Guidelines** — Facility planning and design for healthcare ## Software Workflow | Software | Purpose | |:---|:---| | PlanSwift | Mechanical quantity takeoff from PDF plans | | Bluebeam Revu | Plan markup and code compliance verification | | Trimble Accubid | MEP labor and material pricing | ## Common Estimating Risks | Risk Area | Typical Impact | Mitigation | |:---|:---|:---| | Missing OSHPD seismic bracing | $300k–$500k scope gap | Use California-specific RSMeans adjustments | | HEPA filtration under-specified | $400k+ equipment gap | Build room-by-room ASHRAE 170 matrix | | ICRA compliance omission | Back-charge to mechanical sub | Price as separate Division 01 line item | | Medical gas verification missed | Code violation, project delay | Include ASSE 6010 testing in base estimate | ## Lessons Learned 1. **National averages fail in healthcare.** RSMeans data without California-specific OSHPD adjustments creates massive scope gaps. 2. **Room-by-room analysis is mandatory.** ASHRAE 170 compliance cannot be approximated by square footage. 3. **ICRA costs are real.** They are not general conditions — they are measurable, quantifiable mechanical scope. ## How F&K Applies This Process F&K Estimatings treats every healthcare estimate as a code compliance exercise first and a quantity exercise second. The methodology documented in this walkthrough — seismic bracing quantification, ventilation matrix construction, ICRA pricing, and NFPA 99 gas piping — is applied systematically to every hospital and healthcare project we estimate. --- *This walkthrough is an educational sample based on representative healthcare estimating practices. Figures are illustrative and rounded for clarity. Specific project details are generalized to protect confidentiality.*

HVAC Estimating for a 280-Bed Hospital by F&K

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