You did everything right. You got three quotes for your new roof. One is $14,000, one is $18,500, and one is $22,000. So you go with the cheapest, right?

Maybe. But here’s the problem: almost no contractor will tell you: those three quotes are almost never for the same job. One uses a synthetic underlayment and a full manufacturer warranty; another uses basic felt and a warranty that’s voided the day it’s installed. One is for windows that meet Energy Star requirements and will reduce your energy bills in the long term, and the other just addresses an aesthetic update.  The price difference usually isn’t “one company is greedy” — it’s that you’re comparing three different projects.

The good news: once you know which line items to look for, you can normalize the quotes and compare them honestly. This guide walks you through exactly how — first the rules that apply to every exterior project, then the specific things to check for roofing, siding, and windows.

The universal checklist: what every quote should spell out

Before you look at a single trade-specific detail, every legitimate quote — roof, siding, or windows — should clearly answer these. If a quote doesn’t, that’s not a price you can trust; it’s a guess.

1. A detailed scope of work, not a one-line price. “Replace siding — $24,000” tells you nothing. You want a line-by-line description of what will be removed, installed, and hauled away.
2. Exact materials: brand, product line, and color. “Architectural shingles” or “vinyl siding” isn’t enough. You want the manufacturer, the specific product line, and the model/series — because the difference between a builder-grade and premium line within the same brand can be huge.
3. Tear-off and disposal. Is the old material being fully removed and hauled away, or covered over? Is dumpster/disposal included in the price or billed separately?
4. The two warranties — material vs. workmanship. This trips up almost everyone. The material warranty comes from the manufacturer. The workmanship (labor) warranty comes from the contractor and covers installation mistakes. Ask for both: how long and what does it cover?  A great material warranty installed badly is worth very little.
5. License and insurance — Ask for the license number and a Certificate of Insurance (general liability + workers’ comp). If a worker is injured on an uninsured job, the liability can land on you if the contractor is not adequately covered.
6. Timeline and payment schedule. When does it start, how long will it take, and what’s the payment structure? Be cautious of any contractor demanding a large upfront deposit!  Our standard terms are for a 1/3 deposit, unless the project is being funded through one of our flexible payment options.
7. The change-order policy. When a crew opens up a wall or roof and finds hidden damage, what happens? A clear, change-order process and clearly outlined costs protects you from a surprise bill.
8. Who actually does the work? In-house crews or subcontractors? Neither is automatically bad, but you deserve to know who’ll be on your property and who stands behind the work.

Once all your quotes answer these eight items, you can line them up. Below are the extra, trade-specific items that quietly make quotes stop matching each other.

Comparing roofing quotes

Roofing is where “the same roof” varies the most. Make sure each quote specifies:

1. Tear-off vs. layover, and how many existing layers. Removing the old roof down to the deck costs more than going over it — but a layover hides problems, shortens lifespan, and can make the manufacturer warranty null and void. Compare like for like.
2. Decking/sheathing replacement. Bad plywood underneath is common and can’t be seen until the tear-off. The honest quote states a per-sheet price, so you’re not surprised. Beware of companies that build sheets into the cost, unless there has been a clear assessment from an attic inspection – otherwise, you risk being overcharged for something from the beginning!  A quote that’s silent on this is the one that surprises you mid-job.
3. Underlayment type. Premium synthetic vs. basic felt. They are not the same product or price.
4. Ice-and-water shield. A waterproof membrane at eaves, valleys, and penetrations. How much coverage? In our climate, it matters for ice dams.
5. Flashing — new or reused. New metal flashing at chimneys, walls, and valleys vs. reusing rusty old flashing is a real cost and quality difference.
6. Drip edge, starter strip, and ridge cap. Cheaper bids sometimes omit drip edge or cut up field shingles for the ridge instead of using matched, warrantied components.
7. Ventilation. Proper intake/exhaust ventilation protects the roof and your warranty. Is it being assessed or ignored?
8. The warranty system. Top-tier warranties (like Owens Corning’s Platinum Protection) require the full manufacturer system installed by a certified contractor. Mixing brands of components typically voids the system warranty — so confirm both the certification and that a complete system is being quoted.
9. Cleanup. Dumpster, debris haul-away, and a magnetic nail sweep of your yard.

Comparing siding quotes

Siding quotes hide their differences in the material spec and the accessories. Check:

1. Material and product line. Vinyl, insulated vinyl, and James Hardie are completely different products at completely different price points. Within vinyl, panel thickness/gauge matters. Get the specific brand and line.
2. Tear-off vs. install over existing. Removing old siding lets the crew inspect and repair what’s underneath; going over it is cheaper but can trap problems and void the manufacturer warranty for the newly installed product.
3. Weather-resistive barrier and insulation. Is a house wrap being installed? Is there an insulation board behind the siding, and is it true insulation or thin fan-fold? This affects both price and energy performance.
4. Sheathing/rot repair. As with roof decking, ask how hidden rot is handled and priced.
5. Trim, soffit, fascia, and accessories. J-channel, corner posts, soffit, and fascia are where scopes diverge. A quote covering only the field siding and not the trim isn’t comparable to one that includes it.
6. Finish and finish warranty. For fiber cement, a factory finish (like Hardie’s ColorPlus) carries its own finish warranty vs. field painting. Confirm which you’re getting.
7. Flashing around windows and doors. Proper flashing prevents water intrusion — a quality difference that doesn’t show up in the sticker price.

Comparing window quotes

Windows have the single most important variable that homeowners miss:

1. Installation method. full-frame vs. insert (pocket). A full-frame replacement removes the window down to the studs and lets the installer flash and insulate properly; an insert drops a new window into the existing frame and is faster and cheaper but keeps the old frame. These are different projects — make sure all quotes use the same method, or note the difference.
2. Frame material. Vinyl, wood, fiberglass, and composite differ widely in price and longevity. Get the specific brand and series.
3. The glass package. This is where quotes secretly diverge: double vs. triple pane, the type and number of Low-E coatings, argon/krypton gas fill, and the spacer. Two “double-pane vinyl windows” can perform very differently.
4. Energy ratings. Look for the ENERGY STAR label for our climate zone and compare the U-factor (lower is better insulation) and SHGC. These numbers let you compare performance objectively.
5. Exact count, sizes, and styles. Double-hung, casement, slider, bay/bow — confirm the quote lists every opening so nothing’s missing.
6. Exterior capping and interior finish. Is the exterior trim being wrapped/capped in aluminum? Who repairs and paints the interior trim afterward — the contractor, or you? This is a frequent hidden cost.
7. Lead-safe practices. If your home was built before 1978, the installer should follow EPA lead-safe (RRP) practices. Confirm they’re certified — it protects your family and is the law.
8. Sealing and warranty. Proper foam-sealing of gaps, plus the warranty on glass seal failure and labor, and whether it transfers.

Red flags that should make you slow down

No matter the trade, be cautious when you see:

1. A price dramatically below the others. It’s not a gift — find what’s being cut (tear-off skipped, cheaper materials, no permit, thin warranty, new company that cannot provide adequate customer service). Sometimes it’s legitimate; often it’s a scope difference in disguise.
2. A large upfront deposit. A modest deposit is normal and required by law; a demand for half or more before work begins is not.
3. Verbal promises not in writing. If it’s not in the contract, it doesn’t exist.
4. Reluctance to share a license number or insurance certificate.

Your apples-to-apples scorecard

Lay your quotes side by side on identical rows. Make each contractor quote the same scope and materials — or note exactly where they differ — then compare.