Each bid must be enclosed in a sealed envelope which shall be clearly labeled with the words "Bid. You will need to have contract examples when submitting your bid proposal.Craft persuasive bid proposals for construction projects with this comprehensive guide. Explore key components, from project overview to pricing details. In this article, learn how to customize a construction proposal template that you can use when participating in bids. The Bid Proposal Form is to be filled in, signed, and all required documents are to be placed in a sealed envelope bearing the words "Clubhouse.