Design and construct vs tender: which suits your warehouse?
By Brenscot Builders | Last reviewed September 2026
There are two common ways to procure a new warehouse. Under design and construct (D&C), one company designs the building and builds it. Under a traditional tender, you have the building designed first, then ask several builders to price the finished drawings and build to them.
Both end with a warehouse. They differ in who is responsible for the design, when the builder gets involved, and where the risk of gaps and changes sits. The right choice depends on how finished your brief and your drawings really are.
The short answer
Choose a traditional tender when the design is complete, coordinated and approved, and you want builders to compete on price. Choose design and construct when you have land and a brief but not a finished design, and you want one company responsible for getting from concept to a completed building. Most problems arise when a project is tendered before the design is genuinely finished.
How design and construct works
You give the builder a brief: what the building needs to do, the site, the budget and the timing. The builder engages and coordinates the designers and consultants, develops the design, obtains the approvals and constructs the building under a single contract.
The consultants still do their jobs and still certify their own work. A structural engineer designs the structure, a civil engineer designs the earthworks and stormwater, and a private building certifier assesses the building against the National Construction Code (NCC). The difference is that they are coordinated by the company that has to build the result, and that company carries the responsibility for the design being buildable and complete.
What D&C does not do is remove all risk. Genuine changes to the brief, latent ground conditions (hidden problems such as rock or soft soil) and authority requirements can still change cost and time. What it reduces is the gap between what was drawn and what can actually be built for the money.
How a traditional tender works
You engage an architect or building designer and the engineers directly. They complete the design and documentation, and you obtain the approvals. You then invite builders to tender, compare the prices and award a construct-only contract.
This works when four things are true:
- The brief is settled and will not change during construction
- The drawings and specifications are complete enough that every builder is pricing the same thing
- The structural, civil, fire and services designs are coordinated with each other
- Someone on your side is managing the consultants and the builder, and resolving questions as they arise
When those conditions are not met, the tender price is not the final price. Each omission or clash in the documents becomes a variation, and the builder is generally entitled to be paid for it because the builder did not produce the design.
Side by side
| Question | Design and construct | Traditional tender (construct only) |
|---|---|---|
| Who is responsible for the design? | The builder, under one contract | You and your consultants |
| When does the builder get involved? | From concept | After the design is finished |
| Best suited to | A brief and a site, with the design still to be developed | A complete, coordinated and approved design |
| Main cause of variations | Changes to the brief | Gaps in the documents, plus changes to the brief |
| Price competition | On the brief, between D&C builders | On the drawings, between tenderers |
| Number of contracts you manage | One | Several: designers, consultants and builder |
| Programme | Design, approvals and procurement can overlap | Sequential: design, then tender, then build |
Why D&C suits most SEQ warehouse projects
A warehouse is a simple-looking building with a lot of interdependent decisions. A few examples:
- Height and fire compartment size. Under NCC 2022 Volume One, Table C3D3, a Type C warehouse fire compartment is limited to 2,000 m2 of floor area and 12,000 m3 of volume. Adding a metre of clear height can push a building over the volume limit and trigger fire walls or other measures. See fire walls and fire compartments.
- Site levels and stormwater. The stormwater design sets the surface levels, which set the slab level, the driveway grades and the retaining walls. If the civil design is finalised after the building design, something has to be redrawn.
- Wall system and boundary setbacks. In a typical (Type C) warehouse, an external wall less than 3 m from a side or rear boundary needs a fire resistance level under the NCC. That affects whether the wall can be metal cladding or needs to be concrete. See wall systems compared.
When these decisions are made by separate consultants at different times, they conflict. When they are made together by the team that will build the result, they can be resolved early, when changes cost the least.
When a tender still makes sense
If you already have full engineering, a resolved fire and civil design, development and building approvals, and someone to manage the contract, tendering to several builders is a legitimate strategy. It is not the service Brenscot focuses on, and we would rather say so than price documents we had no part in.
Frequently asked questions
What is a design and construct contract?
It is a building contract under which the builder is responsible for both designing and constructing the building to meet the client's brief. In Australia, standard forms such as AS 4902 are commonly used for D&C, although many projects use amended or bespoke contracts. Have any contract reviewed by a construction lawyer.
Who carries the design risk under design and construct?
Primarily the builder, subject to the terms of the contract. Under construct only, the client carries the risk that the design is incomplete or wrong, because the client supplied it.
Is design and construct cheaper than tendering?
It can be, but compare total finished cost, not the contract sum alone. A tender price covers only what is documented. A D&C price covers the design fees, the approvals management and the construction.
Can I still choose my own finishes and layout under D&C?
Yes. You set the brief and approve the design as it develops. The earlier a decision is made, the less it costs to change.
Does Brenscot tender on other people's drawings?
Our focus is design and construct and our own developments. If your design is substantially complete we are happy to discuss it, but we will tell you if we think a tender is the better path.
Sources
- National Construction Code 2022, Volume One, Table C3D3 (maximum size of fire compartments) and Specification 5 (fire-resisting construction), Australian Building Codes Board, ncc.abcb.gov.au
- Standards Australia, AS 4902 General conditions of contract for design and construct
General information only
This article is general information, current as at September 2026. It is not legal, procurement or design advice. Contract forms and risk allocation are specific to each project. Obtain advice from a construction lawyer before signing a building contract.
Planning an industrial warehouse?
Talk to Brenscot about your site or your requirements. Call 0480 800 077, email enquiries@brenscot.com.au, or start an enquiry. You can also read how we work.