Site-Built Baseline
$975,000
2,150 sq ft • 16.5 mo
Prefab Off-Site Total
$728,450
1,680 sq ft • 6.2 mo
Net Cost Reduction
-$246,550
25.3% Total Savings
Financing & Labor Saved
$58,200
10.3 months faster delivery
Modular Site Layout & Fabrication Footprint
1,680 sq ft • 4 Pods
Conditioned Module
Wet Core / Kitchen
Deck / Breezeway
Crane Pick Point
Click pods above in the sidebar to toggle room modules. Hover over layout to inspect factory dimensions.
1-Day Crane Rigging Required
| Phase / Trade Item | Traditional Site-Built | Prefab Modular | Variance |
|---|
Parallel factory fabrication cuts construction schedule by up to 65%, avoiding weather delays and cutting construction loan interest payments.
Traditional Site-Built Schedule: Permitting, Framing, Weather Delays & Finishing
16.5 Months
Prefab Modular Schedule: Concurrent Foundation & Off-Site Factory Build
6.2 Months
Construction Loan Carrying Cost Model:
At 7.5% interest on an average drawn capital balance of $480,000, cutting 10.3 months saves approximately $30,900 in loan interest alone, plus $27,300 in site security, temporary power, dumpster rentals, and contractor insurance.
Comparison of on-site general contractor labor hours vs controlled climate factory labor hours:
| Trade Craft | Traditional Field Hours | Prefab Total Hours | Hours Eliminated | Field Wage Premium Saved |
|---|
Architectural Grounding & Estimation Methodology
1. Downsizing via Spatial Efficiency
In high-cost markets like the Hamptons ($600–$900/sq ft for custom stick-built), every square foot eliminated saves thousands. By consolidating corridors, integrating custom built-in cabinetry, and using vaulted ceiling envelopes, a 1,680 sq ft layout matches the livability of an older 2,150 sq ft plan.
2. Concurrent Factory Fabrication
Traditional construction is strictly sequential: excavation → foundation cure → framing → rough MEP → insulation → drywall → finish carpentry. Prefab builds the entire envelope in an enclosed plant while site grading and foundations happen in parallel.
3. High-Cost Labor Premium Arbitrage
Resort and coastal markets suffer from extreme subcontractor shortages and commute surcharges. Factory modular construction builds modules in regional manufacturing plants where hourly production wages are 35–45% lower than on-site Hamptons or Aspen framing crews.