Commercial roofing projects often involve decisions about scope, materials, upgrades, and budget priorities. Property owners may want to compare different roofing options without requiring contractors to submit completely separate proposals.
One effective way to evaluate options is through bid alternates.
Bid alternates allow contractors to provide pricing for additional work, upgraded materials, or alternative solutions that are not included in the base bid. When structured properly, bid alternates give owners flexibility while maintaining a fair and transparent bidding process.
What Is a Bid Alternate?
A bid alternate is a separate price option included in a contractor’s proposal that allows the owner to add, remove, or modify specific portions of the project.
A bid alternate may represent:
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An upgrade
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A different material option
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Additional work
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Reduced scope
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A design change
The owner can decide whether to accept or reject the alternate after reviewing pricing and project priorities.
Example of a Roofing Bid Alternate
A commercial roofing project may have:
Base Bid:
“Install a 20-year TPO roofing replacement system.”
Alternate #1:
“Upgrade insulation system from R-20 to R-30.”
Alternate #2:
“Replace existing roof drains with new cast iron drains.”
Alternate #3:
“Add a 25-year manufacturer warranty system.”
The owner can compare the costs and benefits before making a final decision.
Why Are Bid Alternates Important?
Bid alternates provide several advantages for commercial property owners.
Better Budget Control
Owners can evaluate optional improvements without affecting the entire project budget.
More Competitive Bidding
Contractors price the same base scope while providing comparable alternatives.
Easier Decision Making
Owners can prioritize upgrades based on:
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Available funding
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Long-term value
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Building requirements
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Future maintenance goals
Improved Transparency
Clearly structured alternates prevent contractors from including optional work inconsistently in different proposals.
Common Roofing Bid Alternates
The right alternates depend on the project, but common commercial roofing alternates include:
1. Roofing System Upgrades
Examples:
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Upgrade from standard membrane to premium membrane
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Increase membrane thickness
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Upgrade attachment method
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Add enhanced wind resistance
2. Insulation Improvements
Examples:
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Additional insulation thickness
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Higher R-value assemblies
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Energy-efficiency upgrades
These may improve:
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Energy costs
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Building comfort
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Long-term performance
3. Roof Replacement vs. Restoration Options
Owners may request alternatives such as:
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Full roof replacement
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Roof coating restoration
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Overlay system
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Partial replacement
This allows comparison of different lifecycle strategies.
4. Warranty Upgrades
Examples:
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Longer manufacturer warranty
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Enhanced contractor warranty
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Additional inspections
Warranty alternates help owners evaluate long-term protection.
5. Metal and Flashing Upgrades
Examples:
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Replace existing sheet metal
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Upgrade coping systems
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Improve edge details
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Replace drainage components
How Should Bid Alternates Be Structured?
A properly structured bid alternate should be clear, measurable, and independent.
Each alternate should include:
1. Alternate Number and Description
Example:
“Alternate No. 1 – Provide additional insulation to achieve R-30 roof assembly.”
This creates a consistent reference.
2. Detailed Scope
The alternate should explain:
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What is added
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What is removed
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Materials involved
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Installation requirements
Avoid vague descriptions.
3. Pricing Format
The contractor should clearly state:
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Addition cost
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Deduction cost
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Unit prices, if applicable
Example:
“Add: $25,000”
or
“Deduct: $15,000”
4. Impact on Schedule
The alternate should identify whether it affects:
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Start date
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Completion date
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Installation sequence
5. Warranty Impact
The proposal should explain whether the alternate changes:
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Manufacturer warranty
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Contractor warranty
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Maintenance requirements
6. Acceptance Deadline
Owners should know when alternates must be accepted.
Some material costs may change over time, so contractors may provide pricing validity periods.
Bid Alternates vs. Allowances
Bid alternates and allowances are different.
Bid Alternate
A known optional item with a defined price.
Example:
“Upgrade insulation system: Add $30,000.”
Allowance
A budget amount for uncertain work.
Example:
“Include $20,000 allowance for unforeseen deck repairs.”
Alternates provide options, while allowances address unknown conditions.
Common Mistakes When Using Bid Alternates
Property owners should avoid:
Comparing Unequal Alternates
All contractors should price the same alternate requirements.
Accepting Alternates Without Reviewing Impact
An upgrade may affect:
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Warranty
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Maintenance
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Future repairs
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Building performance
Choosing Based Only on Price
The lowest alternate price may not provide the best long-term value.
Best Practices for Commercial Roofing Bids
Owners should require contractors to:
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Use the same bid format
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Clearly separate base bid and alternates
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Provide detailed descriptions
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Identify exclusions
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Explain warranty differences
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Include schedule impacts
A consistent format makes contractor comparisons much easier.
Frequently Asked Question
What are bid alternates and how should they be structured?
Bid alternates are optional pricing items included in a roofing proposal that allow property owners to add, remove, or modify portions of the project scope. They should be structured with clear descriptions, separate pricing, defined materials, schedule impacts, and warranty implications. Properly structured bid alternates help commercial property owners compare options, manage budgets, and make informed decisions without creating confusion between competing roofing proposals.
For commercial roofing projects, well-designed bid alternates create flexibility while maintaining transparency, fairness, and better control over project outcomes.
Related Questions
- What is bid leveling and how should it be done?
- What allowances are typical for deck replacement in a bid?
- What is a pre-bid site walk and should attendance be mandatory?
- Should I always choose the lowest bid for a commercial roofing project?
- How many bidders should be invited to a commercial roof project?
- Should I use design-build or design-bid-build for a roofing project?
- Can I get an accurate bid without a full roof tear-off inspection?
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