The gap they fill
A contractor is in contract with the employer. Consultants are in contract with whoever appointed them. A funder lending against the scheme, a purchaser buying it and a tenant taking a lease are in contract with none of them.
If a defect emerges, those parties have no direct route to the person responsible. A collateral warranty creates one: a separate agreement under which the contractor or consultant owes a duty directly to that third party.
The alternative mechanism is third party rights conferred under the contract itself, which achieves a similar outcome by a different route and avoids a separate signing exercise.
They also matter more than most developers expect on schemes intended to be sold or refinanced, because the buyer’s solicitor will produce a list and the absence of anything on it becomes a condition of completion. A document nobody thought about for two years then sits on the critical path of a transaction.
Who typically requires them
Funders almost always, because their security depends on the building being sound and they will want the ability to step in if the developer fails. Purchasers and their own funders on a completed sale. Tenants on longer leases, particularly of whole buildings.
On residential schemes, warranty requirements interact with the new build warranty provider’s own regime, which is separate and covers different things. [VERIFY: the specific requirements of the new home warranty provider being used on the scheme.]
The practical point is that the list of people who will want one is knowable at the start of a project, and it is far easier to build the obligation into every appointment than to negotiate it afterwards.
Why late is expensive
A contractor or consultant asked to give a warranty after their work is complete and their account is settled has no commercial reason to agree. They may do it as a matter of relationship, they may charge for it, and they may simply decline.
Where the request comes during a sale process, the absence of a warranty becomes a price issue, because the buyer prices the risk they are being asked to take without recourse.
The cost of getting it right at the outset is a clause in each appointment and a schedule listing who is entitled to what. The cost of getting it wrong is a negotiation with no position.
What to look at in the document
Three things carry most of the commercial weight. The extent of the duty, meaning whether it matches the underlying appointment or is narrower. Any cap on liability, and whether it is shared across all beneficiaries or applies to each. And the assignment provisions, meaning how many times the benefit can be passed on as the building changes hands.
Net contribution clauses are the ones developers most often accept without noticing. They limit each party’s liability to their fair share rather than allowing recovery of the whole loss from whoever is solvent, which changes the practical value of the warranty considerably.
None of this is a reason to refuse them. It is a reason to read them alongside the appointment rather than as a separate administrative task.
Keeping track
On a scheme with a main contractor, several consultants and a number of design responsible subcontractors, the number of warranties required can run to dozens, each needing execution by a specific party in favour of specific beneficiaries.
The administrative failure is common and avoidable: a schedule maintained from the start, showing who owes what to whom and what has been executed, turns it into a checklist. Without one it becomes a search shortly before a completion date.
That schedule belongs with whoever is administering the contract, because they are already tracking the parties and the packages.
What this means for you
Decide at the outset who will need warranties, including parties you do not yet have, and write the obligation into every appointment and subcontract from the beginning.
Keep a live schedule of what has been executed. It costs nothing to maintain and it prevents the version of this problem that delays a sale.
Getting the obligation into the documents is part of tendering and procurement, and tracking execution through the job sits with the employer’s agent appointment.
One point that catches developers on residential schemes. Where units are being sold to individual purchasers, the warranty regime that matters to them is usually the new home warranty rather than a collateral warranty, and the two cover different things over different periods. Establishing which parties need which document, early, avoids providing the wrong protection at some expense.