Residential service work is usually estimated and closed in one visit. Commercial and heavy-highway work runs through a bid process, which is a different discipline. The paperwork matters as much as the price.
A typical commercial bid package includes:
- Invitation to bid (ITB) with submittal deadline and bonding requirements
- General conditions from the general contractor or owner
- Drawings (architectural, structural, MEP)
- Specifications (division-organized per CSI MasterFormat)
- Addenda issued during bidding (always read every addendum; specs change)
- Bid form and bid bond requirements
Walk the job before you bid if the general contractor offers a pre-bid walk. The drawings never tell the full story. Site access, existing conditions, trade stacking, and storage all affect price.
Your proposal should spell out what is included, what is excluded, and what is allowed only as a change order. Common exclusions to consider for trades: bonds above a certain dollar threshold, prevailing wage (if you are not prevailing-wage shop), permit fees, material escalation, site cleanup beyond your own work, and hazardous material abatement.
Payment terms. Most commercial contracts run on a 30-day pay schedule with retainage (commonly 5 to 10 percent). Understand when retainage is released. Sometimes not until owner final acceptance months after you leave the site. Factor cost of money into your price on long jobs.
Lien rights. File your preliminary notice in states that require one (California's 20-day preliminary notice is the classic example). Miss the window and you cannot lien the job if you do not get paid.