Siding estimates can vary wildly—sometimes by $10,000 or more for the same job. Without a systematic way to evaluate them, you're likely leaving money on the table or accidentally choosing a contractor who'll cut corners. Here's how to dissect each estimate so you can compare apples to apples.
Break Down Materials by Type and Quantity
The material line item is usually the largest expense, but contractors rarely spell out what you're actually getting. Ask for the specific product name, grade, and square footage. If one bid says "vinyl siding" and another says "Certainteed CedarSoft shakes," those aren't equivalent—one might cost 40% more but last 20 years longer.
Request a material takeoff: the exact linear feet of trim, corner posts, J-channel, and starter strip. A $3,500 difference in material costs between two bids often signals that one contractor underestimated or is using lower-grade stock. Call them back and ask for clarification—not judgment, just facts.
Examine Labor Costs and Crew Size
Labor typically makes up 40–60% of a siding job. A reasonable labor estimate for a full exterior re-siding runs $8,000–$20,000 depending on your home's size, complexity, and your region. Two contractors might quote the same price but plan different timelines: one with a four-person crew finishing in two weeks versus a two-person crew taking four weeks.
Shorter timelines aren't always better (rushed work shows), but they may indicate efficiency. Ask how many people will be on site and what their typical schedule is. If a bid is suspiciously low on labor, ask whether it includes prep work like removing old siding, installing house wrap, and flashing windows—these steps easily add $2,000–$5,000 if omitted.
Watch for Hidden Costs
This is where estimates diverge most. Here's what to explicitly ask about:
- Removal and disposal of old siding: $1,500–$4,000 depending on square footage. Some contractors roll this in; others tack it on separately.
- Underlayment or house wrap: $0.50–$1.50 per square foot. Essential for moisture protection but sometimes listed as "optional."
- Flashing and caulk: Windows, doors, and trim edges need quality sealing. Budget $800–$2,000 if not detailed.
- Soffit, fascia, and gutters: Full exterior work often includes these. Verify whether they're covered or separate line items.
- Permits and inspections: $300–$1,000 depending on your municipality. A contractor should never hide this cost.
- Cleanup and haul-away: $500–$1,500. Ask if dumpster fees are included or if they're billing separately.
Compare Warranties Side by Side
Manufacturer warranties and workmanship guarantees vary drastically. One contractor might offer a 30-year material warranty but only a 2-year labor guarantee; another might offer 10-year coverage on both. Create a simple table:
| Contractor | Material Warranty | Workmanship Warranty | Who Backs It | |---|---|---|---| | Bid A | 30 years | 5 years | Manufacturer / Contractor | | Bid B | 15 years | 2 years | Manufacturer only |
A longer warranty often reflects higher confidence and material quality—but read the fine print. Some warranties only cover the original homeowner, or they're prorated (you pay more as years pass).
Check References and Timeline Details
Ask each contractor for three references from similar jobs completed in the past 12 months. Don't just call them; ask specific questions: Did the crew arrive on time? Was cleanup thorough? Have any issues emerged since completion?
Also nail down the timeline. When will they start? How many days will the work take? What happens if weather delays the job? A vague estimate like "sometime in spring" is a red flag. Reliable contractors commit to specific start and completion windows.
Use a Comparison Spreadsheet
Create a simple sheet listing every line item from all three bids in the same order. Highlight the high and low prices for each category. This prevents your eye from just landing on the total and makes obvious where the biggest differences lie.
Platforms like Mercoly let you compare multiple siding contractor estimates in one place, which saves the manual spreadsheet work and helps you identify patterns across local providers.
Frequently Asked Questions
Q: Should I always choose the lowest estimate? Not necessarily. The lowest bid often means skipped steps, lower-grade materials, or inexperienced crews. Choose the estimate that matches your material preferences, timeline, warranty coverage, and reference quality—not just price.
Q: How long should a siding job take? A typical full exterior siding replacement on a 2,000-square-foot home takes 10–15 business days for a well-staffed crew. Smaller repairs or partial re-siding might take 3–7 days.
Q: What warranty length is standard for residential siding? Most manufacturers offer 20–30 year warranties on vinyl and fiber cement, though workmanship guarantees from contractors usually run 2–10 years.
Start comparing estimates today—your bottom line depends on it.