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Facilities Engineering "Select Best Bids By Qualifications"
How owners and facility managers prequalify enclosure contractors, write bid documents that allow qualifications-based selection, and compare bids fairly.
Article by Dwight Benoy, P.E.
Read the full article (PDF)Background on this topic from Inspec
A bid number is a price, not a plan
When roofing, waterproofing or facade repair work goes out to bid, the spread between the highest and lowest number is often large enough to make the decision look obvious. It rarely is. A bid is one contractor's read of the drawings and specifications, priced against the crews, materials and schedule that contractor expects to commit. Two bidders looking at the same documents can arrive at very different numbers because they are pricing different amounts of work, different qualities of material, or different levels of supervision.
Selecting on qualifications does not mean ignoring price. It means knowing what each price actually buys before the numbers are compared, and confirming that the contractor holding the low number is capable of delivering the scope the documents describe. That determination is made long before bid day, in how the project is packaged and who is invited to bid.
What qualifications actually predict performance
For enclosure work, the qualifications that matter are specific to the assembly being installed, not to construction generally. A contractor with a strong record in single-ply roofing may have no experience with hot fluid-applied waterproofing, masonry repointing or curtain wall glazing. Useful criteria include:
- Experience with the specific system, not the general trade — the membrane, sealant family, cladding type or waterproofing chemistry named in the specification.
- Manufacturer approval status for the system being installed, where the specified warranty depends on it.
- Who will actually be on the roof or the swingstage, including the foreman assigned to the project and whether the work will be self-performed or subcontracted.
- Bonding and insurance capacity appropriate to the contract value.
- Current backlog and available crews, measured against the schedule the project requires — particularly where seasonal weather limits the installation window.
- References on comparable buildings, ideally occupied ones, where the owner can be asked about coordination, cleanliness and how change orders were handled.
- Safety record and site logistics planning for an occupied building with tenants, pedestrians and parked cars below.
Write the bid documents so qualifications can be judged
Owners often want to weigh qualifications and then discover the bid documents give them no basis to do it. Selection criteria have to exist in the documents before bids are opened.
Prequalify before the invitation goes out
The simplest approach is to control the bidder list. A prequalification questionnaire issued in advance — covering system-specific experience, manufacturer status, key personnel, bonding, backlog and references — lets the owner establish that every bidder is acceptable before any price is submitted. Once that is done, comparing prices is a defensible exercise, because all of the numbers came from contractors the owner would be willing to hire.
Specify the scope so it cannot be priced two ways
Wide bid spreads usually trace back to ambiguity. If the documents do not state how much deteriorated deck to assume, how many linear feet of sealant to remove and replace, or what happens where existing flashing is found to be inadequate, each bidder will make a private assumption. The careful bidder carries the risk in the number; the aggressive bidder leaves it out and recovers it later as a change order. Quantities, assumed conditions and the limits of the work should be stated in the documents, not left to interpretation.
Use unit prices and alternates for concealed conditions
Enclosure repair almost always involves conditions that cannot be seen until tear-off. Unit prices for deck replacement, masonry unit replacement, blocking or substrate repair let all bidders carry the same base assumption and give the owner a pre-agreed rate for whatever is found. Bid alternates handle scope the owner may or may not fund, and keep the base bid comparable across all bidders.
Say how the award will be made
Public owners frequently operate under a low responsible and responsive bidder requirement. That standard still permits qualification criteria, provided the criteria are stated in the invitation to bid and applied to every bidder equally. Responsiveness concerns whether the bid conforms to the documents; responsibility concerns whether the bidder is capable of performing. Both can be defined in advance.
Reading the bids you receive
On bid day, the tabulation is the beginning of the review, not the end. Bids should be checked for exclusions and qualifications written into the cover letter, substitutions offered in place of specified products, unit prices that are unrealistically low or high, and math or omissions that suggest a bidder missed part of the scope. A number that sits far below the others deserves a conversation before it is accepted — an unintentional omission discovered after award becomes the owner's problem, either as a change order or as a contractor working at a loss.
A post-bid interview with the apparent low bidder is worth the hour. Walking through the scope, the schedule, the staging plan and the assigned foreman confirms that the bidder priced the job the owner intends to buy.
Where a consulting engineer fits
Inspec is a consulting engineering and architecture firm. We do not perform repair work and we do not sell materials, so the recommendation we give an owner is not tied to any product line or installation contract. Our involvement typically begins well before bidding: investigating the condition, testing where testing is warranted, and preparing the drawings and specifications the bids will be based on. Clear documents are the single largest factor in whether bids come back comparable.
Through construction observation and administration, we can help owners review submitted bids, and observe the work as it is installed so that what was specified is what gets built. Contractors looking for projects currently out for bid can review our current bidding projects.
If you are preparing to bid roofing, waterproofing or facade repairs and want the documents to support a defensible award, contact us from our offices in Chicago, Milwaukee or Minneapolis.