Prefab homes have shed their outdated reputation—modern modular construction offers real cost transparency and faster builds than traditional stick-framing. But "all-inclusive" pricing masks significant variation, and understanding what actually gets bundled into your quote is critical before committing. This breakdown walks you through the line items that make up a prefab house price, so you know exactly what you're paying for.
The Factory Build: Your Largest Cost Component
The factory-built modules themselves typically consume 40–60% of your total project cost. This covers materials, labor, equipment, and overhead at the manufacturer's facility. A single-story, 1,000 sq ft module costs between $80,000–$150,000 depending on finish level and regional production expenses. Two-story homes or those with premium finishes (high-end cabinetry, tile, custom layouts) push toward $180,000–$250,000 per module.
This is where quality varies dramatically between builders. Some manufacturers use engineered lumber and standard fixtures; others source solid wood, premium appliances, and European plumbing fixtures. Request a detailed materials list—don't settle for vague "luxury finishes" language. Ask whether electrical and plumbing rough-ins are included (they should be) and whether HVAC systems come pre-installed.
Site Preparation and Foundation Work
Foundation costs are rarely included in the factory price and run $15,000–$50,000+ depending on soil conditions and site complexity. Modular homes require a fully finished foundation before modules arrive—concrete slab, pier-and-beam, or basement. Poor soil or sloped terrain dramatically increases expenses.
Site prep itself (clearing, grading, utility access roads) adds another $5,000–$20,000. If you're building in a rural area with limited road access, expect the high end or beyond. Get a geotechnical survey done early; it costs $1,500–$3,000 but prevents expensive surprises.
Transportation and Placement
Shipping modules from the factory to your site costs $3,000–$15,000 per module, depending on distance and road conditions. A two-module home might see $8,000–$25,000 in transport alone. Crane rental for placement runs $2,000–$8,000 per day; most placements take one to three days.
These costs scale with complexity—a difficult site access or a home requiring multiple modules adds up quickly. Confirm whether your quote includes actual placement and temporary crane standby, or if you're responsible for hiring the crane operator separately.
On-Site Assembly and Connections
After modules arrive, they need to be leveled, connected, and integrated with utilities. This labor typically costs $15,000–$40,000 for a two-module home. The builder's crews seal connections between modules, integrate electrical and plumbing systems, install connecting walls or hallways, and ensure everything meets local building codes.
This is where inexperienced modular builders cut corners. Verify your contractor has completed at least 5–10 similar projects. Ask for references and request on-site photos during assembly phases.
Utilities and Final Connections
Connecting to municipal water, sewer, electrical, and gas lines—or installing septic, well, and propane systems—runs $8,000–$35,000 depending on existing infrastructure. Urban sites with utilities already at property lines cost far less than rural builds requiring new utility trenches.
Verify who pays for utility permits and inspections. Some builders include these; others bill them separately.
Permits, Inspections, and Soft Costs
Building permits, modular inspections, and engineering reports typically cost $2,000–$8,000. Some jurisdictions are modular-friendly and streamlined; others require additional site-specific engineering, adding $3,000–$5,000. Your contract should specify who handles permitting and whether costs are capped.
What to Compare Across Quotes
When evaluating multiple prefab builders, use this checklist:
- Factory build cost and what materials/appliances are included
- Foundation and site prep responsibility (builder or homeowner)
- Transportation, placement, and labor costs
- Utility connection and inspection fees
- Warranty coverage (factory defects vs. on-site workmanship)
- Timeline and penalties for delays
Use Mercoly to compare trusted modular and prefab construction providers side by side—it's the fastest way to see which builders include what in their pricing.
Frequently Asked Questions
Q: Are appliances and flooring included in the factory price? Most prefab manufacturers include basic appliances and standard vinyl or laminate flooring; premium upgrades (stainless steel, hardwood, granite) cost extra and should be quoted separately.
Q: Can I change designs or layouts after ordering? Factory changes mid-production are expensive or impossible; most builders offer change orders only before manufacturing starts, with significant upcharges for custom modifications.
Q: What's the realistic timeline from order to move-in? Expect 6–9 months total: 3–4 months factory build, 1–2 months site prep and foundation, 2–3 weeks on-site assembly, plus permit and utility delays.
Get detailed cost breakdowns from at least three builders before deciding.