How to Estimate and Bid a Siding Job

A good siding bid is accurate on quantities, honest about unknowns and easy for the homeowner to read. The estimate is the math; the bid is how you present it. This guide walks through both.

1. Take an accurate take-off

Everything downstream depends on area, so measure carefully. Take wall lengths and heights, gable dimensions and every opening, then compute net area. The steps are in how to measure for siding, and the Siding Calculator totals them for you.

Photograph each elevation and note conditions: existing material, rot, second stories, difficult access, and anything that affects labor.

2. Choose waste realistically

Waste comes from cuts at corners, openings and gable angles, plus damaged pieces. Pick a number that reflects this house and this product, not a blanket percentage. The siding waste factor guide covers typical ranges, and the waste calculator applies it.

3. Convert to materials

Divide required area by product coverage and round up to whole boxes or boards. Then add the parts that are bought by length or count:

Starter strip, J-channel, corner posts and trim (trim calculators)
House wrap, tape and flashing (house wrap calculator)
Fasteners, caulk and sealants
Soffit and fascia if they are in scope

If you need to convert squares to boxes and pieces, see squares and pieces in a box of siding.

4. Price labor

Many crews price labor per square, while others use hours multiplied by a crew rate. Whichever you use, adjust for stories, access, complexity, and the material, since fiber cement is heavier and slower to install than vinyl. Include tear-off and disposal when replacing existing siding.

5. Add overhead and profit

Materials plus labor is your direct cost. Insurance, vehicles, tools, office time, permits and warranty work are real costs that need to be covered, and the business also needs a profit. The right percentage depends on your own numbers, so calculate it from your actual overhead instead of copying a rule of thumb. Many contractors end up applying a combined markup somewhere in the range of roughly 15% to 30%, but yours may differ.

6. Handle unknowns in writing

Rot behind old siding is the classic surprise. State how hidden damage will be priced (for example, per linear foot or per sheet of sheathing) and require approval before extra work starts. A contingency line of 5% to 10% in your internal estimate is common.

7. Present a clear bid

A homeowner should be able to compare your bid with two others in a few minutes. Include:

Scope of work and exclusions
Product line, profile and color
Measured area and squares
Total price, and price per square if you want to show it
Payment schedule and estimated timeline
Warranty terms for product and workmanship

Use the Siding Cost Calculator to run scenarios and sanity-check your totals against the ranges in how much siding costs.

Frequently asked questions

How do you estimate a siding job?

Measure walls and gables, subtract openings, add waste, and convert to squares. Price materials, trim and accessories from that quantity, add labor and any removal or repair work, then apply overhead and profit.

How do you price a siding job per square?

Add your material, labor, removal, and accessory costs for the whole job, then divide by the number of squares. Dividing your final price by squares lets you compare bids and check whether your numbers fall in a normal range for the material.

How much waste should I include in a siding bid?

Ten percent is a common starting point for a simple house, and 15% or more for houses with many gables, dormers or angled cuts. Base it on the actual layout and product, not a fixed habit.

What should a siding bid include?

A clear scope of work, product and color, quantities, exclusions, price, payment schedule, timeline, warranty terms, and how hidden damage found during tear-off will be handled.

Do I need to test for lead paint before residing?

For homes built before 1978, US EPA renovation rules generally require lead-safe work practices and certified firms when a renovation disturbs painted surfaces. Check current EPA and state requirements before quoting.