Window installation contract template — measurement, lead-safe and rot
Window contracts turn on who measured. Custom units are non-returnable, so the measurement clause decides who pays for a mistake.
This is a checklist of what a window installation contract has to settle — not a ready-to-sign legal document, and not legal advice. Most states regulate home improvement contracts: required disclosures, cancellation windows, deposit limits and licence display all vary, and some trades carry extra rules. Adapt this, then have a lawyer in your state review it before you put it in front of a customer.
Download as a spreadsheet to work through, or print it to sit alongside your own agreement.
What a window installation contract has to settle
A window contract has to say who is responsible for the field measurements, because units are made to order and a wrong size is a total loss, not a return. It also has to distinguish insert from full-frame per opening, since they are different prices and different scopes. Lead-safe work practices are a legal requirement on pre-1978 housing. Rot at the sill is the standard discovery and needs an allowance with a per-opening rate rather than a conversation held with the wall open.
Clauses it needs
- Parties, licence number, and every opening listed with its size
- Who performs the field measurements, and who bears a sizing error
- Insert or full-frame installation, stated per opening
- Unit specification: frame material, glass package, U-factor and SHGC
- Rot and jamb repair allowance, with a per-opening rate
- Lead-safe work practices where the property predates 1978
- Egress sizing where a bedroom window is replaced
- Flashing, sill pan and air sealing named in the scope
- Lead times, storage of delivered units, and weather-tight-by-end-of-day terms
- Manufacturer warranty registration, and the installation warranty term
What window installation contracts actually get argued over
- A mis-measured custom unit, with no clause saying whose error it was
- Rot repair billed with no allowance and no photograph
- Openings left unsecured overnight, with no weather-tight obligation
- Trim damage on removal, where trim reuse was assumed but never agreed
The estimate this contract is built on
A contract can only be as clear as the scope it references. BidWand drafts the itemised estimate — labour, materials, exclusions and assumptions — that the scope and exclusions clauses point at.
Draft the window installation estimate this contract references
This generates the estimate, not the contract — describe the job and you get the itemised scope to attach. No email needed to see the first one.
What you get — see the format first
A complete estimate you can send to the customer, built from the rate you enter:
| Description | Qty | Unit | Unit price | Total |
|---|---|---|---|---|
| Labor — itemized by task | hrs | hour | your rate | — |
| Materials — with your markup applied | qty | ea / sq ft | cost + markup | — |
| Permits, disposal, access | — | — | — | — |
Plus a plain-English scope summary, assumptions (what had to be guessed), exclusions (what you are not doing — the section that prevents most change-order arguments), and a validity period. Printable, or send the link.
Every figure comes from the rate and markup you supply. We never fill in a market price for you.
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How to estimate
How to write a contractor estimate · Estimate vs quote vs bid — and which one you should send · What to include in a contractor estimate · How to price a job as a contractor · Should you charge for estimates? · How to follow up on an estimate · How to handle change orders · Estimate vs invoice: what's the difference? · How to raise your prices as a contractor