The «cost per square metre» of an office is a figure that tells you little. Two sites with the same floor area can have radically different budgets, and the difference comes down to variables that can be measured before you even open a specification. Understanding which ones they are – and how to weigh them – is the work that precedes any reliable estimate.
The variables that really matter
The cost of an office project breaks down into four major items, each carrying its own weight:
- Existing condition of the building services. A space whose services need a complete overhaul (electrical, data, air conditioning, fire protection) costs structurally more than one where those systems are already compliant and suited to the new use. This item alone can move the budget by a whole tier.
- Level of finish. Flooring, suspended ceilings, partitions, furniture – across these elements the gap between a functional fit-out and a refined one is wide. The choice is not aesthetic: it enables or limits certain work settings and affects acoustics, maintainability and the identity of the space.
- How many people and how many m² are really needed. An office oversized relative to real use drags along fit-out, rent and running costs that recur every year. Before estimating the cost per m² you have to measure how many m² are needed – and that depends on people's typical day, not on the employment contracts in force.
- Support areas. Meeting rooms, reception zones, break areas, storage, dedicated cabling: these surfaces don't produce workstations but they enable work. Their weight on the total varies, but ignoring them at the estimating stage produces surprises on site.
How to estimate with a method
A dependable estimate starts from the survey of the existing conditions – building services included – and from measuring the space needed. For the latter we use the data gathered through surveys and interviews on the teams' typical day: from the split between focused, collaborative and support activities, with the BOMA method for net areas, we derive the number of work settings and the gross area consistent with real use. Only at that point does it make sense to apply the cost items by category. The result is a range by intervention tier: the variables still open are named.
The link with the desk sharing ratio is direct: knowing how many workstations are really needed – based on actual attendance – reduces the area to fit out and, as a result, the total investment.
What shifts the budget mid-project
The most frequent revisions arise from three situations: services in worse condition than expected, changes to the functional programme decided after works have begun, and finish choices revised without checking the impact on the cost plan. All three are reduced by a more thorough design in the preliminary phase: an accurate survey, a shared brief, a functional programme settled before the offer.
Who leads the project affects the cost
The final cost also depends on who coordinates the work. With an established multidisciplinary team – architects, mechanical and electrical engineers, urban planners – ARCHIlabs integrates the building services and regulatory aspects from the design stage onward, and during delivery it handles works supervision, art direction and testing. A single point of contact reduces coordination costs and the variations that arise when design and execution are in different hands.