The purpose of a request for proposal is not to describe the site you want. It is to get proposals you can actually compare. Most website procurement fails at that first step: a document heavy on wish lists and light on constraints produces replies with different assumptions, different scopes and prices that cannot be set beside one another.
State the constraints, not only the wishes
Budget range, deadline, platform requirements or prohibitions, who maintains the site afterwards, integrations that must work, accessibility standard, and hosting arrangements. These are what make quotes comparable. Withholding the budget produces proposals aimed at the wrong scale and wastes everyone's time, including yours.
Describe outcomes and audiences, not screens
Say who the site is for, what each audience must be able to do, and what currently stops them. A specification written as a list of pages invites a quote for building those pages, which prevents a supplier from telling you that the structure is the actual problem. The best replies to a good brief disagree with something in it.
Ask questions that reveal how they work
Who does the work, what happens when content is late, how change requests are priced, what the acceptance test is, what is handed over, and how support works afterwards. These separate firms more reliably than portfolios do, and the answers are checkable later against what actually happens.
Run it fairly and keep it short
Same document, same questions window, answers published to all bidders, a realistic response time and a small shortlist. Long processes with many bidders produce polished documents from firms with proposal teams rather than the best fit. Three or four serious candidates is usually the right number.
Questions people ask about web design request for proposal
Should the RFP name a budget?
Yes, as a range. It is the single most useful thing in the document, because it tells suppliers which of several possible solutions to propose and makes their replies comparable.
How much detail should the specification contain?
Enough for a supplier to price the work with confidence, and not so much that it dictates the solution. Constraints and outcomes in detail, implementation left open.
Is it fair to ask for design concepts in a proposal?
Asking for unpaid speculative design is widely disliked and tends to attract firms with capacity rather than the best firms. If you want concepts, pay a fee for them and keep the rights.
How long should suppliers get to respond?
Two to three weeks for a substantial project, with a window for questions early. Shorter than that favours firms recycling a previous proposal.