Send the same one-paragraph request to five agencies and you will get five estimates that differ by a factor of three or more. Usually nobody is being unreasonable. Each one has filled the gaps in your request with different assumptions.

A short, clear brief removes most of those assumptions. You do not need technical knowledge to write one, and it does not need to be long. Two or three pages is plenty for most projects.

Why estimates vary so much

The words "a new website" cover everything from a five-page brochure site to a platform with logins, payments and integrations with your internal systems. Even for a simple site, the hidden questions add up:

  • Who writes the content, and is it ready?
  • How many page layouts are really needed?
  • Does existing content need to move from an old site?
  • Which other systems does the site have to talk to?
  • Who will edit the site after launch, and how often?

When these questions are not answered, a careful agency will either ask, add a large safety margin, or quote only what was explicitly described. All three make comparison difficult.

What to include

Use the sections below as a template. If you do not know an answer, say so. "We are not sure yet" is useful information.

1. About your organization

A few sentences about what you do, who your customers are and what makes you different. This helps whoever reads the brief understand the tone and priorities of the site.

2. Goals

What should the site achieve? Be as concrete as you can. "More leads from organic search", "fewer support emails about order status" and "let partners download their own reports" are goals. "A modern website" is not.

If you can, say how you will measure success.

3. Audience

Who visits the site and what do they need to do there? List the two or three most important groups and their main tasks. These tasks become the key user journeys that the design, testing and budget should prioritize.

4. Scope

List the main sections and page types rather than every page. For example: home page, service pages, case studies, blog, team, contact. Note roughly how many of each exist.

Then list the features: forms, search, user accounts, payments, multilingual content, events, a resource library. Mark each one as essential or nice to have. That split is one of the most useful things you can give an estimator, because it allows a phased plan.

5. Content

Who will write and supply the text, images and video? Is the content ready, being written, or not started? Content is the most common cause of delayed launches, and agencies price the risk differently.

If you have an existing site, say whether content should be moved automatically, rewritten, or left behind.

6. Integrations

List every system the site needs to connect to: CRM, email marketing, payment provider, booking system, analytics, single sign-on, internal databases. For each one, note whether it exists already and whether it has documentation. Integrations are often the most uncertain part of an estimate.

7. Technical constraints

Mention anything already decided: a required CMS, hosting provider, security requirements, accessibility standards or compliance obligations. If nothing is decided, say that too. It invites recommendations.

8. Design

Is there a brand guide? Existing designs? Sites you like, and what specifically you like about them? Will the agency design the site, or will designs be provided?

9. Editing and support after launch

Who will update the site, how technical are they, and how often will they publish? Do you expect ongoing maintenance and improvements, or only the build?

10. Timeline

Is there a real deadline, such as a product launch, an event or the end of a contract? Or is the date flexible? A fixed deadline with a large scope changes how a project is staffed.

11. Budget

This is the section people most often leave out, and it is the one that helps most. A budget range lets an agency propose what is realistic for that money instead of guessing what you can afford. You will get more comparable proposals, not just higher ones.

12. Decision process

Who will choose the partner, who approves designs and content, and how quickly can decisions be made? Slow approvals stretch timelines and costs as much as technical work does.

What not to worry about

You do not need to specify technologies, write detailed functional specifications or draw wireframes. A good agency will ask follow-up questions and propose the details. The brief's job is to describe the problem clearly, not to design the solution.

How to use the answers you get back

When the proposals come in, compare how each agency responded to the brief, not just the total price:

  • Did they ask sensible questions, or quote without asking anything?
  • Did they explain their assumptions?
  • Did they suggest phasing the nice-to-have features?
  • Did they point out risks, such as content readiness or a fragile integration?

An estimate with clear assumptions is easier to trust than a lower number with none.

Have a project in mind? Send us your brief through our contact form, even a rough one, and we will reply with questions and a realistic estimate.