A written sliding window quote and a rough estimate are not the same document. An estimate is a number you can scribble on a napkin after a five-minute conversation. A quote is a real document that lists exactly what you are getting, for exactly what price, with a date by which the offer is valid. Knowing the difference is the difference between getting surprised at install time and not.
Here is what a proper written sliding window quote includes, in the order it usually appears on the page.
The contact and project header
The top of any real quote names the parties. Customer name, address, and contact information. Installer name, address, business contact, and (in our case) WhatsApp number. Date the quote was prepared, and a quote reference number.
That section is short but matters. It says this quote is for you, for this address, on this date. If you reference the quote three weeks later in an email, you both know which one you are talking about.
The line items every sliding window quote should have
The body of the quote lists every billable item on the project. For a sliding window install in Jamaica, that means:
- Each window unit by location (for example, “Master bedroom east wall: 5′ x 4′ (60″ x 48″) sliding window”)
- The glass spec per unit (thickness in mm, treatment such as clear, tinted, frosted, tempered, or laminated)
- The aluminum profile name and finish (powder-coated black, white, bronze, anodised, or custom RAL colour)
- Hardware included per unit (lock type, handle finish, roller grade, mosquito mesh, burglar grills if part of scope)
- Removal of the existing windows
- Disposal of the old units and any site debris
- Sealants and trim around each opening
- Scaffold or boom access for any window above ground floor
- Site cleanup after install
- Labour for the install itself, often as a separate line from materials
The line items should add up to a subtotal, with GCT (or other applicable tax) shown separately, and a clear grand total at the bottom. If any of those items is missing or rolled into a vague “supply and install” lump sum, you do not yet have a quote you can compare to anyone else’s.
What good quotes do that bad ones do not
A good quote spells out the spec. A bad quote leaves the spec vague enough that the installer can deliver the cheaper option without breaking the agreement.
A good quote separates labour from materials. A bad quote bundles them so you cannot tell what is being paid for what.
A good quote names every site task. A bad quote assumes you understand “supply and install” includes ten things you might not have realised you were paying for.
A good quote fits on two or three pages and reads like a spec sheet. A bad quote fits on a single line in a text message.
If you find yourself emailing the installer to ask “what does this include,” the quote is doing less work than it should.
Expiration date and what it means
A proper quote has an expiration date, usually 30 days from when it was issued. That is not a sales tactic. It is honest about a real constraint. Aluminum profile prices, glass prices, and hardware costs change. After the expiration date, the installer cannot guarantee the same price because their cost base may have shifted.
If you want to act on a quote that has expired, ask the installer to reissue at current pricing. Most will be quick about it, and the new quote will tell you whether your scope still costs the same or whether the underlying costs have moved.
How to read it before signing
Read the quote twice before you sign anything. The first read is for the bottom line, which is the part most people focus on. The second read is for the line items, which is the part that determines whether the bottom line is actually a good deal.
Compare line by line if you have multiple quotes. The same glass spec, the same hardware grade, the same scope, the same warranty: then you are comparing real apples. If any line is missing on one quote that appears on another, the missing-line quote is not actually cheaper. It is just promising less.
Related reading
- Five things to check before signing a sliding window contract
- How to choose the right glass thickness for sliding windows
Frequently asked questions
What is the difference between a quote and an estimate?
An estimate is a preliminary number based on rough information; it is not legally binding and may not include taxes or final costs. A quote is a detailed written breakdown that can be signed and used as a contract. A quote also typically has an expiration date because material prices change.
How long is a sliding window quote valid?
Typically 30 days from when it was issued. After expiration the installer cannot guarantee the same price because aluminum, glass, and hardware costs change. If you want to act on an expired quote, ask for a fresh one at current pricing.
What line items should be on a written sliding window quote?
Each window unit by location and size, glass spec per unit, aluminum profile and finish, hardware per unit, removal of existing windows, debris disposal, sealants and trim, scaffold access if needed, labour, cleanup, GCT shown separately, and the grand total. Lead time, payment schedule, and warranty terms should also be on the quote.
Should the glass spec be on the written quote?
Yes, in detail. Glass thickness in mm or inches, treatment (clear, tinted, frosted, tempered, laminated), and any coating (Low-E, easy-clean) should be named per unit. A quote that just says “safety glass” with no detail is not specific enough to compare to another quote.
What does “supply and install” mean on a quote?
Literally it means the installer provides the unit and installs it. In practice, used as a single line without breakdown, it tells you nothing about glass spec, hardware, site work, or scope. Ask for the breakdown before accepting any “supply and install” total.
The next step
If you want a written quote on a window project, the quote request form is the fastest way to start. We come back with a document structured the way this article describes, so you have something you can compare to any other quote on the same scope.
The sliding windows service page covers what we typically install. The contact page has WhatsApp and phone for quick questions.
A real quote should answer your questions before you ask them. If yours does not, ask the questions and get them in writing before you sign.