Two-Stage Tender vs Single-Stage Tender: How Each Works and When to Use It

How single-stage and two-stage tenders work

A single-stage tender has one round. Your design team issues a finished set of drawings and a specification. Contractors price them, you compare the returns, and one contractor is awarded the contract.

A two-stage tender has two rounds, with the work between them. The contractor chosen in stage one never prices the whole job against rivals. It is chosen on a short list of numbers and on how it works.

The steps of a single-stage tender are:

1. The design team completes the design and the tender documents.
2. Several contractors are invited to price them.
3. You compare the returns and clarify any gaps.
4. You award the contract to one contractor at its tendered sum.

The steps of a two-stage tender are:

1. You appoint a contractor on overheads, profit, preliminaries and a pre-construction fee.
2. It works with your design team under a pre-construction agreement.
3. The trade packages are tendered open book.
4. The contract sum is agreed in stage two, and you sign the building contract.

Two-stage tender vs single-stage tender compared

The table sets the two routes side by side. Read the rows on risk first: they decide most schemes.

Weak drawings do most damage in a single-stage tender. Our guide on why builders' quotes vary so much shows how contractors fill gaps differently, so you compare unlike prices.

For the wider choice between routes, read design and build vs traditional procurement.

Not sure which route your scheme needs? Our pre-construction services start with a free review of the drawings. Get a free cost and buildability review.

When a two-stage tender is worth it

Choose a two-stage tender when the unknowns in the building are bigger than the cost of finding them early.

These schemes usually qualify:

• Basements and deep excavations next to neighbours.
• Retained façades and listed fabric.
• Occupied buildings that must keep trading.
• Conversions where nobody knows what is behind the plaster.
• Schemes with long-lead items, such as steel, plant or façade panels.

Higher-risk residential buildings also benefit. The Building Safety Regulator must approve them before building work starts, a step covered in our Gateway 2 guide. A builder in the room can plan the programme around it.

A two-stage tender also lets design and procurement overlap. Long-lead packages can be ordered while later design is still being finished.

Single-stage still wins in three cases. The design is complete, the building is simple, and many capable contractors will price it. Then the competition does the work a stage one appointment would do, at no fee.

The two-stage tendering process step by step

The process has six steps, from selection to contract.

1. Select in stage one. Contractors bid on overheads and profit, a preliminaries schedule, their pre-construction fee and how they would run the job.
2. Appoint for pre-construction services. The contractor starts work under a pre-construction agreement.
3. Tender the packages. The contractor tenders each trade package open book, and you see every return.
4. Reconcile the cost plan. The returns are set against your cost consultant's plan until the two agree.
5. Receive the stage-two proposal. It carries the contract sum, programme, clarifications and exclusions.
6. Sign the building contract. Stage two often runs as a JCT Design and Build Contract, after you decide to proceed.

Step 2 uses a document you should read before signing. Our guide to the pre-construction services agreement covers the fee, the services schedule and your exit. JCT publishes a form for it, designed for appointing a contractor under a two-stage tender process.

Not every contract needs the same form. JCT contract types explained shows how to match the building contract to the design.

Early builder input pays off on a hard site. At Slingsby Place in Covent Garden the works were led by Martin Hickey, now our Preconstruction Director, as Project Director. The temporary works for the façade retention were signed off before demolition.

How to keep competition in a two-stage tender

A two-stage tender costs you leverage once one contractor is preferred. You win it back in stage one. Fix these numbers before you appoint, and leave the price open.

Three habits keep the price honest:

1. Have every package return sent to you and your cost consultant, not only to the contractor.
2. Benchmark the contractor's cost plan against an independent one before stage two.
3. Set a long-stop date, after which either side can end the agreement.

If the stage-two price comes in high, you hold three options. Ask for value engineering of the packages that moved most. Re-tender those packages. Or stop and pay only the pre-construction fee, using the work product if your agreement gives you a licence.

Negotiated tenders, two-stage design and build and public clients

A negotiated tender agrees the price with a chosen contractor, rather than awarding it on competing bids. It is quick, but nothing tests the price. A two-stage tender keeps stage-one competition and tests stage two against package returns.

Two-stage design and build is the same process with the contractor taking design responsibility for parts of the work. The building contract at stage two is then a design and build form.

Public clients tender under the Procurement Act 2023. Its open procedure is "a single-stage tendering procedure without a restriction on who can submit tenders". Any other competitive process is a competitive flexible procedure. By that definition a two-stage route sits there, and the authority must make it a proportionate means of awarding the contract.

The Cabinet Office published a Two Stage Open Book model in 2014. The client invites teams to bid on an outline brief and a cost benchmark, and awards the contract at the second stage. It was written under EU rules, so read it as a model, not as current law.

Use this list to decide your route. Want a second opinion on the scheme and the drawings? Get a free cost and buildability review. Already have a quote? Send it to us. We'll beat it.