When you commission an office renovation, the way the contract is structured determines how much the client can understand of what they are paying for. There are two basic models – fixed price and open book – and the difference is not only economic: it is a matter of visibility over your own investment.
Fixed price: certainty and opacity
With a fixed price the client receives a single all-inclusive amount: materials, labour, coordination and the general contractor's margin are aggregated into one figure. The advantage is real – the final expense is defined from the start, and the risk of variations and contingencies is transferred to the coordinator. The trade-off is that the internal structure of the costs remains invisible: it is impossible to distinguish the actual cost of the works from the compensation of those coordinating them, or to assess how much individual design choices affect the overall budget.
Open book: transparency item by item
With the open book approach the client has access to the actual quotes of every supplier and subcontractor. The coordinator adds an agreed, separate fee, covering design work, site management and supervision. This makes it possible to read the offer by homogeneous items, compare alternatives during execution and understand where choices of quality or timing have an impact. If a variation emerges during the works, the client sees the actual cost of the change.
On the left the cost reads as one single block. On the right every item is distinct and verifiable, with the coordination fee kept separate.
What the client sees in each model
The choice between the two models depends on the priorities of the commissioning organisation. A fixed price is preferable when certainty over the final budget outweighs everything else – for example in operations with a rigid budget and binding deadlines. Open book is better suited when the client wants to keep visibility over costs through time, compare the impact of alternative choices or build an ongoing working relationship with the coordinator. In both cases, the quality of the upstream design – the precision of the works specification, the completeness of the technical requirements – is what reduces variations and stabilises the final cost.
The value of knowing what you are paying for
Cost transparency is not an absolute advantage in every situation, but it is a tool that allows the client to make informed decisions. An offer that is readable item by item makes it possible to weigh alternatives during the project, to recognise when a variation is necessary and when it is discretionary, and to compare different offers on a like-for-like basis. Understanding the structure of what you pay is the first step towards managing an investment well.
How ARCHIlabs applies the open book model
Open book is the economic model with which ARCHIlabs runs the delivery phase in its own design & build. When the client chooses to entrust the studio with the works as well as the design, the contractors' costs remain visible and distinct from the fee agreed for coordination. The goal is for every choice – of material, supplier, timing – to be made with full awareness of its economic weight.