Prefab Delivery Savings Calculator

Prefab saves cost and time. This calculator sizes benefits.

Site-built cost

Prefab cost

Schedule savings months

Monthly carry

Quality premium %

Total savings

$933,000

Direct cost savings

$600,000

Schedule carry savings

$255,000

How the math works

Direct savings = site − prefab. Schedule savings = months × carry. Quality value = prefab × quality premium.

Prefab saves schedule at the same time as it saves cost — rare combination. A 3-month schedule savings on a project with $85k/month carry adds $255k to the direct cost savings alone. Evaluate prefab feasibility at design phase; retrofitting prefab into a site-built design rarely works.

How to Use

Enter site-built cost.
Enter prefab cost.
Enter schedule savings months.
Enter monthly carry.
Enter quality premium %.
Read net savings.

Frequently Asked Questions

Prefab categories?

MEP racks/manifolds. Headwalls for hospitals. Exterior wall panels. Bathroom pods. Kitchen modules. Factory floors and conveyors. Each can save 10-30% cost and 2-6 months schedule when design supports prefab.

Cost savings?

Labor efficiency (controlled environment): 15-30% labor cost reduction. Material waste reduction: 5-10% savings. QC improvement: fewer rework costs. Total typically 10-20% versus same scope site-built.

Schedule impact?

Parallel execution: prefab happens while site prepares. Saves 15-35% of critical path time. Particularly valuable on MEP rough and exterior enclosure. Schedule savings often more valuable than cost savings on interest-carry-heavy projects.

How does this interact with the rest of the capital stack?

Each tier of the stack affects the next. Senior debt constrains LTC and DSCR. Mezz and pref consume equity spread. Interest rate hedges protect DSCR but cost premium. Always model the full stack holistically — optimizing one tier alone often degrades another. Institutional underwriters run three or four scenarios across the stack before committing capital.