Design and construct, or design then tender?
One contract with one party accountable, or two with a competitive price. On a clinical fitout the answer leans one way more than people expect.
The short answer
This decision gets made by default more often than it gets made deliberately, usually because somebody knew a builder or somebody knew an architect. It’s worth ten minutes of actual thought.
Key points
- D&C: one contract, the builder carries design responsibility.
- Traditional: your designer documents it, builders tender on that document.
- D&C is usually faster and gives one party to hold accountable.
- Traditional gives an independent designer and a competitive price on fixed scope.
- Clinical fitouts are services-led, which tends to favour D&C.
This decision gets made by default more often than it gets made deliberately, usually because somebody knew a builder or somebody knew an architect. It’s worth ten minutes of actual thought.
Design and construct, or design then tender
Design and construct. One contract with one party. The builder takes responsibility for both the design and the construction, either with an in-house team or with consultants they engage. You hold one party accountable for the outcome.
Traditional, or design then tender. You engage a designer and consultants directly, they document the project, and builders tender on that documentation. You hold two separate relationships and the design belongs to you.
There’s also novation, a common middle path: you engage the designer to develop the concept, then transfer that appointment to the builder, who carries it through to completion. You control the early design and the builder carries the risk afterwards.
What each one gives you
| Design and construct | Design then tender | |
|---|---|---|
| Program | Faster. Design and early works overlap | Slower. Documentation completes before pricing |
| Price certainty | Early, against a brief | Later, against a full document |
| Accountability | One party | Two, with a gap between them |
| Design control | Less. The builder owns the design | More. The designer works for you |
| Competitive tension | Priced once, up front | Multiple builders on identical scope |
| Where it fails | Quality erodes if the brief is vague | Disputes fall into the gap between designer and builder |
Why clinical work tends to favour D&C
Because on a clinical fitout the services drive the design, and separating the two creates a seam exactly where the risk is.
Where the chair position goes determines where the slab is cut. What the equipment schedule says determines the room. What the mechanical engineer needs determines whether the plant fits. A designer producing a beautiful set of drawings without a builder confirming those things is producing a document that gets revised during construction, and revisions during construction are variations.
The counter-argument is real, though: D&C only works if your brief is good. A builder given "six consulting rooms and a treatment room" will deliver exactly that, at the specification they assumed. Everything you did not say becomes their choice, made in their interest.
How to make D&C work
Write a proper brief. Room schedule, equipment schedule, finishes level, acoustic expectations, the standards that apply. This site's room schedules exist partly so you can.
Specify, don’t describe. "Full-height acoustic partitions to consulting rooms with cavity insulation and sealed door sets" is enforceable. "Good acoustic separation" isn’t.
Name the standards. AS 1428.1, AS 1668.2, AS/NZS 4815, the RACGP Standards where you’re accredited. Written into the contract, not assumed.
Deal with the allowances. Provisional sums and PC items are where a D&C price drifts, so list them and interrogate the assumptions.
Keep an independent eye if the project is significant. A superintendent or client-side representative costs a fraction of the contract and works for you rather than for the party you are paying.
When traditional is the better answer
- The design matters commercially in its own right, as in a cosmetic clinic where the interior is the product
- You have a strong view on the design and want to keep control of it
- The project is large enough that competitive tender on a fixed scope saves more than the extra program time costs
- You already have a designer you trust who knows clinical work
Neither is wrong. Choosing by default is.
Sources and further reading
Procurement and contract structures vary. Have any building contract reviewed by a construction lawyer before signing.
The National Construction Code: building classification, fire separation, egress, sanitary provisions and access.
Source for AS/NZS 4815 and 4187 reprocessing, AS 1428.1 access and AS 1668.2 ventilation. The standards themselves are purchased, not free.
Room-by-room design guidance and standard components used across Australian health projects, including consulting, treatment and sterilising rooms.
Questions
What is a design and construct contract?
A single contract in which the builder takes responsibility for both design and construction, using an in-house team or consultants they engage. You hold one party accountable for the outcome rather than managing a designer and a builder separately.
Is design and construct better for a medical fitout?
It tends to suit clinical work, because the services drive the design and separating the two creates a seam where the risk is. But it only works with a good brief: anything you do not specify becomes the builder's choice, made in their interest.
What is novation?
A middle path where you engage the designer to develop the concept, then transfer that appointment to the builder who carries it through. You control the early design and the builder carries the risk from that point.
When is design then tender the better route?
When the design matters commercially in its own right, such as a cosmetic clinic where the interior is part of the product; when you have a strong view you want to keep control of; when the project is large enough that competitive tender on fixed scope outweighs the extra program time; or when you already have a designer who knows clinical work.
How do I stop quality dropping under design and construct?
Specify rather than describe. 'Full-height acoustic partitions with cavity insulation and sealed door sets' is enforceable; 'good acoustic separation' is not. Name the standards in the contract, interrogate the provisional sums, and consider an independent superintendent.
Send us the floor plan
A site assessment tells you what the tenancy can take and what it will cost to get there, ideally before you have signed for it.