How to Quote Siding Replacement: A Contractor's Field Guide

Building an Accurate Siding Replacement Quote

A solid siding replacement quote starts long before you open a proposal template. Miss a line item — tear-off disposal, j-channel on every window, a rotted band board hiding under the old clapboard — and you're eating that cost out of margin. This guide walks through every major component of a siding replacement quote so you can price the job completely the first time, whether you're a solo operator doing three houses a month or running a small crew through a full neighborhood.

Step 1: Measure in Squares, Not Just Square Feet

Siding is sold and estimated in squares. One square equals 100 square feet of coverage. Get comfortable moving between the two, because suppliers quote you in squares while takeoffs start in square feet.

How to Take Off the Wall Area

1. Measure the total perimeter of the structure and multiply by the wall height for each story. Do each story separately if heights differ.
2. Calculate window and door openings. Subtract them — but read your material supplier's policy. Some contractors deduct openings smaller than a set size (say, under 15 square feet) and don't bother for anything smaller. Pick a consistent rule and stick to it.
3. Add gable ends. Measure the base and height of each triangle, multiply, divide by two.
4. Total everything in square feet, then divide by 100 to get squares.

Waste Factor

Always add a waste factor on top of your net squares. A simple ranch with long unbroken runs needs less overage than a Victorian with a dozen corners, multiple gable angles, and window after window. As a rule of thumb:

• Simple box house, few openings: 5–8% waste
• Average home with normal window count and a couple of gables: 10% waste
• Complex rooflines, lots of angles, heavy trim detail: 12–15% waste

Order short and you're making a mid-job supplier run. Order with enough cushion and you have spare material for callbacks.

Step 2: Price the Tear-Off Separately

Tear-off is its own cost center. Don't fold it into your labor rate and hope for the best. You need to account for:

• Labor to strip: How many hours per square to pull and toss the existing material? Vinyl strips faster than wood. Multiple layers of old siding — especially if there's original wood under aluminum under vinyl — take significantly longer.
• Dumpster or haul-away: Price the bin rental or your dump fees directly into the quote. If you're not running your own trailer, get a dumpster quote before you write the proposal.
• Disposal surcharges: Some materials, particularly older fiber cement or anything you suspect might have been treated, can carry disposal restrictions. Know your local rules.

A clean single-layer vinyl tear-off on a straightforward house is a very different scope than stripping cedar shingles that have been painted four times. Line-item the tear-off so the customer understands what they're paying for, and so you can adjust it cleanly if the scope changes on day one.

Step 3: Housewrap and Sheathing — Don't Assume

Once the old siding is off, you're going to find one of a few situations: solid sheathing in decent shape, sheathing that needs spot repairs, sheathing that needs full replacement, or in older homes, skip sheathing or nothing at all. You won't know until you're looking at it.

If you're quoting a job sight-unseen or from photos, build in an allowance for sheathing repairs and be explicit in your contract language that full replacement is a change order. Surprises in sheathing are one of the fastest ways to blow a siding budget.

Housewrap

New housewrap goes on virtually every full re-side job. Price it as a material line item — roll quantities based on your square footage — plus the labor to install and tape it properly. Don't skip the tape budget; sealing the laps and penetrations is what makes the wrap work.

Step 4: Material Types and Their True Installed Cost

The material you're installing drives everything: panel size, installation speed, fastener requirements, trim compatibility, and waste rates. Here's a working comparison of the most common options:

When building your siding replacement quote, pull your actual current supplier pricing — don't work off memory. Material costs move, and a quote built on last season's prices can cost you real money.

Step 5: Trim, Flashing, and Accessories

This is where a lot of contractors leave money on the table or get burned. Trim and accessories are not a rounding error — on a typical house they can add up to a meaningful portion of total material cost.

What to Count and Price

• Starter strip: Full perimeter at the base. Measure every linear foot.
• J-channel: Every window, every door, every penetration. Walk the house and count every opening.
• Outside and inside corner posts: Count corners carefully. A simple ranch might have four outside corners. A house with bump-outs, bay windows, and garage columns can have fifteen or more.
• Soffit and fascia: If it's in scope, measure it separately. It often goes hand-in-hand with a re-side but has its own material and labor rate.
• Frieze board and belly band: If the design includes horizontal trim breaks, price the material and the added labor for fitting siding to them.
• Window and door casing/trim: Does the customer want new exterior trim wrapped or replaced? Get this defined before you write the quote.
• Flashing: Head flashing above windows and doors, step flashing at any wall-to-roof transitions, kickout flashing where roof meets wall. These are not optional — they're code and they're what keeps water out. Price the material and the time to do it right.
• Caulk and sealant: Budget generously. Running short on caulk is a nuisance; missing penetrations costs you a callback.

Step 6: Labor — Build It From Time, Not Instinct

The most reliable way to price labor is to estimate actual hours, then apply your fully-loaded crew rate. Avoid the habit of pulling a per-square labor number out of the air without checking it against real job history.

Labor Components to Break Out

• Tear-off (hours per square by material type)
• Housewrap installation
• Sheathing repairs (if scoped, or carry an allowance)
• Siding installation (hours per square — this varies by material and complexity)
• Trim and accessory installation (often takes as long as the field siding on a complex house)
• Flashing installation
• Cleanup and haul-away (if not covered in a separate dumpster line)
• Caulking and touch-up

If you're running a crew, factor in setup time, drive time if it's not local, and any equipment rental — lifts, scaffolding, or specialty saw setups for fiber cement all need to appear somewhere in the number.

Putting the Quote Together

A complete siding replacement quote should be readable by the customer and auditable by you. Structure it so you can find your line items if something changes mid-job. At minimum, your proposal should cover:

1. Scope description — what's included and what's explicitly excluded
2. Tear-off and disposal
3. Housewrap and any sheathing repair allowance
4. Siding material (specify product, color, profile)
5. Trim and accessories (itemized or as a grouped line)
6. Flashing
7. Labor
8. Any painting or caulking if in scope
9. Payment terms and change order language

If you're using a quoting tool like Renoz, you can build a template for siding jobs that carries all these line items forward automatically — so you're not rebuilding the structure from scratch on every proposal. That consistency also makes it easier to review your margins across jobs and spot where your estimates are drifting from actuals. You can see how Renoz structures this on the features page.

A Few Things Worth Putting in Writing

Before you submit any siding replacement quote, make sure your contract addresses:

• What happens if there's rotted sheathing or framing behind the old siding. Change order trigger, unit price, or an allowance — pick your approach and spell it out.
• Material lead times. If the product is on a four-week lead, the customer needs to know that before they sign.
• Who supplies paint or stain if the siding requires a site-applied finish coat.
• Access requirements. Do you need the homeowner to clear landscaping or move vehicles? Put it in writing so you're not losing time on day one.

A well-built siding replacement quote protects you as much as it sells the job. Take the time to measure accurately, price every component, and write a scope that reflects what you're actually doing — and you'll have a lot fewer uncomfortable conversations when the job is in progress.

If you're looking for a faster way to build complete, professional estimates for siding and other exterior work, check out the Renoz quote generator. It's built for contractors who want to spend less time on paperwork and more time in the field. You can also review plan options to find the right fit for your volume.