MEP ROM Estimator

How This Works

This tool provides a Rough Order of Magnitude (ROM) estimate for MEP systems based on building type benchmarks. ROM estimates are typically within -25% to +50% accuracy — they are for early feasibility and budgeting, not for bidding.

Methodology:

• Base cost: Total construction cost per SF is estimated by building type (national averages from published industry data). MEP percentage is then applied.
• MEP percentage of total: Varies by building type — from ~12% for industrial to ~40% for hospitals. These are industry-standard ranges published by MEP industry associations and preconstruction benchmarks.
• Trade split: The MEP total is split into Mechanical, Electrical, Plumbing, and Fire Protection based on typical ratios for each building type.
• Location factor: Regional cost adjustment based on published city cost index data. National average = 1.00.
• Quality tier: Budget multiplier 0.85, Standard 1.00, Premium 1.20. Reflects system quality, redundancy, and specification level.

Important caveats:

• ROM estimates are not proposals or bids. Accuracy is conceptual (-25% to +50%)
• Site-specific conditions (soil, existing utilities, phasing, access) are not included
• Specialty systems (medical gas, lab exhaust, clean rooms) require separate analysis
• Default percentages are industry norms — override with your experience for better accuracy
• Location factors are approximate — verify with local contractors for current market conditions

Sources: MEP cost percentages derived from published industry benchmarks including RSMeans Building Construction Cost Data references, Wohlsen Construction MEP cost studies, ASHRAE Handbook cost data, and preconstruction industry consensus. Location factors based on published city cost indices. All defaults are editable — this tool shows its assumptions and lets you override them.