A sole source specification names one manufacturer and one product, with no alternative permitted. Sometimes that is the right answer. Frequently it is a specification written years ago for a different project, and it removes the competition from a package before anybody has priced it.
Three kinds of restrictive specification
They are not the same thing and the distinction matters commercially.
Proprietary or sole source. One manufacturer, one model, no substitution. The package has one supplier and the price is whatever that supplier says it is.
Basis of design with or equal. One product is named as the standard, and equivalents are permitted subject to approval. This is the normal form and it preserves competition, provided the approval process actually works.
Closed list. Two or three named manufacturers, no others. A compromise that preserves some competition while controlling quality, and often the sensible answer.
Owners tend to assume they are looking at the second when they are looking at the first. The difference is one sentence in the specification and it can be worth a great deal of money.
A sole source specification is not improper. On systems where the owner has a maintenance standard, a portfolio commitment or a genuine performance requirement met by one product, it is correct. The question is whether anybody made that decision deliberately for this project, or whether it arrived in a specification section copied forward.
What a sole source specification does to the price
The direct effect is obvious. A supplier with no competitor prices accordingly, and the premium on a genuinely sole sourced package is commonly between ten and twenty five percent.
The indirect effects are larger and less visible.
Lead time stops being negotiable. A competitive package can be steered toward the supplier who can deliver in time. A sole sourced one delivers when that manufacturer delivers, which makes the schedule a function of one company order book.
Change pricing loses its discipline. Every subsequent addition to that package is priced by the same supplier under the same absence of competition, for the life of the project.
The buyout upside disappears. Packages that come in under their carried value are the source of the buyout position described in construction buyout savings, and a sole sourced package will not be one of them.
And the risk of a single supplier failing, or simply declining to quote, has no fallback. On a competitive package that is an inconvenience. On a sole sourced one it is a redesign.
How to tell whether it was a decision
Four questions, and the answers take minutes.
Who asked for it. An owner standard, an operator requirement or a brand mandate is a decision. A designer preference may be a decision or may be inertia. Neither is wrong, but the owner should know which.
What is the performance requirement behind it. Where a real requirement exists it can usually be written as performance language, which preserves competition while protecting the outcome. Where none can be articulated, the restriction is habit.
Is it consistent across the documents. A specification naming one manufacturer while the drawings show a detail matching a different one is a copied section, and it is also a conflict of the kind described in when drawings and specification disagree.
How many packages are affected. One sole sourced elevator specification is a considered position. Fourteen sole sourced sections across mechanical, electrical and finishes is a document that was not reviewed.
A worked example
Illustrative figures. Not taken from any client project and not a quotation.
A 58 million dollar hospitality project. Eleven specification sections name a single manufacturer with no substitution permitted, across lighting, door hardware, plumbing fixtures, rooftop equipment and controls.
Of the eleven, three are genuine brand standard requirements imposed by the operator and are not negotiable.
Of the remaining eight, six are sections carried forward from a previous project by the design team and nobody can state a performance requirement behind them. Two are designer preference on visible finishes, which is a legitimate aesthetic decision.
Converting the six to a closed list of three acceptable manufacturers produces competitive pricing on packages worth $4.1 million in total. The buyout comes in at $620,000 below the carried figures.
The conversion takes one meeting with the design team, before the packages are tendered. After tender it takes a redesign and it does not happen.
The three operator standards remain sole sourced, correctly, and are priced as such. That is not a finding. It is a cost of the brand, and it belongs in the budget rather than in an argument.
The or equal process, and why it usually fails
Where a specification does permit equivalents, the substitution machinery decides whether that permission is real.
Three provisions determine it. How long the reviewer has to respond. What evidence a proposer must submit. And who pays for the redesign consequences if an equivalent is accepted and turns out to require changes elsewhere.
A process with an open ended review period and a requirement that the proposer carry all consequential design costs is a process nobody will use. The specification says or equal and the project behaves as though it were sole sourced.
That is the worst of both positions, because the owner has paid for a competitive specification and is receiving sole source pricing.
Fixing it is a matter of two numbers: a review period measured in days, and a statement of who carries consequential design cost. Both belong in the contract at signature rather than in a substitution request in month nine.
When restriction is the right answer
It is worth being clear that the objection here is to accidental restriction rather than to restriction itself.
A portfolio owner who maintains sixty buildings with one controls platform has an excellent reason to specify it, and the premium on the package is smaller than the cost of running two platforms.
A hotel operating under a brand agreement has requirements that are not negotiable and should not be spent time on.
A healthcare owner standardizing medical gas equipment across a campus is buying serviceability, and that is a real benefit that does not appear in the construction cost.
In each case the restriction has an owner behind it who can state the reason. The finding is never that a specification is restrictive. It is that eleven sections are restrictive and nobody can say why eight of them are.
The practical output of the exercise is therefore a short list rather than an objection. Which sections are restricted, who asked for each, and what the competition removed from each one is worth. Three columns, one page.
With that page in front of them, an owner can make a deliberate decision on each line, and will usually keep three or four of the restrictions and open the rest. That is a different conversation from the one that starts with an estimator asking why a package has only one supplier.
It is also a conversation that has to happen before the packages go out to tender, because after that the answer costs a redesign instead of a meeting.
On a portfolio, the same page is worth keeping between projects. Most design teams carry their specification library forward, which means the eight sections nobody could justify on this building will arrive again on the next one unless somebody writes down what was decided.
Owners who build repeatedly and keep that record stop having the conversation at all after two or three projects, because the library has been corrected at the source.
What we do
We count the restrictive sections, separate the ones with an owner or operator requirement behind them from the ones that were copied forward, and price the competition that has been removed from each. Then we read the substitution machinery to see whether or equal means anything on this contract. The work is part of the constructability and interface review. With three weeks or more before signature, the full pre-GMP review reads the price, the schedule, the interfaces and the change exposure together.
Questions people ask
Is sole sourcing ever cheaper?
Occasionally, where an owner buys the same product across a portfolio and holds a negotiated national agreement, or where standardization removes spare parts and training costs over the building life. Those are real savings. They are also calculable in advance, which distinguishes them from a specification nobody examined.
Who should raise this, the owner or the contractor?
The contractor usually notices first, because the estimator sees a package with one supplier. Whether it gets raised depends on timing and incentive. It is far more reliably found by reading the specification sections before tender, which is a short exercise on a list of the larger packages.
Can a substitution be proposed after award?
Contracts generally allow it, and the practical answer is usually no. After award the trade contract is priced on the specified product, the shop drawings are under way, and any saving is negotiated rather than competed. Substitution has commercial value before tender and very little afterwards.
This is general information about construction contracts and is not legal advice.