What Moves A Price On A Modular Project
Factory delivery gives earlier cost certainty, and the variables that remain are mostly outside the module. Knowing which ones they are makes a feasibility honest instead of optimistic.
What makes a modular project cost more or less?
The site and its access, the groundworks and foundations the ground conditions require, the authority and service connection requirements, the degree of repetition across dwellings, the specification level of finishes and services, the crane and transport arrangements the site allows, and the external works. The modules themselves are the most predictable part of the cost.
The module is the predictable part. It is made in a factory, to a drawing, in a controlled sequence, and the cost of it is known early.
What moves a project price is almost everything else, and it is worth knowing which items carry the movement before a feasibility is signed off.
The site, first and largest
**Access.** Whether a truck carrying a module can reach the installation position, and whether a crane of the required capacity can be set up where it needs to be. A site that requires a larger crane, a road closure, a traffic management plan or an overnight delivery window carries real cost, and that is set by geometry rather than by anything in the building. The variables are in [crane selection and lift planning](/blog/crane-selection-and-lift-planning).
**Ground conditions.** The single largest unknown on most projects. Rock, fill, reactive clay, a high water table or contamination each change the foundation solution and the excavation cost, and none of them are visible from the surface. This is why the geotechnical investigation happens early rather than at documentation, and it is the subject of [groundworks and foundations for modular](/blog/groundworks-and-foundations-for-modular).
**Slope.** A fall across the building footprint means retaining, a split level, a suspended floor or imported fill, and the cost scales quickly. Dealt with in [building on sloping sites](/blog/building-on-sloping-sites).
**Services.** Where the connections are, what capacity exists, and what the authority requires to connect. An upgrade to a service main or an on-site detention requirement can be a significant line item, and it is discovered through enquiry rather than assumption, which is why [utility connections and authority approvals](/blog/utility-connections-and-authority-approvals) sit early in the programme.
Repetition, which works in both directions
Repetition is where factory delivery pays.
A project of several dwellings to the same design costs materially less per dwelling than the same number of individual designs, because the design is done once, the fabrication sequence is set up once, and the labour learns the build. That is the argument in [multi-dwelling projects and the value of repetition](/blog/multi-dwelling-projects-and-the-value-of-repetition).
A single bespoke dwelling carries the whole design and setup cost on its own, which is why a one-off is proportionally more expensive than a project of eight.
Specification, which is a choice rather than a constraint
Finishes, joinery, tapware, appliances, flooring and window treatments all have a wide range, and the range is wider than most people expect.
So does the services specification: a split system versus a ducted system, solar and batteries, the hot water type, the lighting approach. Each is a decision with a cost and a whole-of-life consequence that may run the other way, which is why they are evaluated against [maintenance and whole-of-life costs](/blog/maintenance-and-whole-of-life-costs) rather than on capital cost alone.
The point is that specification is controllable. It is the part of the budget that can be tuned without changing the building.
External works, consistently underestimated
Driveways, paths, parking, fencing, landscaping, retaining, stormwater, mail delivery points, clotheslines and external storage.
None of it is in the module and all of it is required for the dwelling to be occupied. On projects that run over budget, this is where a disproportionate share of the overrun sits, because it is estimated last and scoped loosely. The full list is in [landscaping and external works](/blog/landscaping-and-external-works).
Programme, where time is money in both directions
A shorter programme reduces holding costs, finance costs and the period before the asset produces income, which is a real saving on the project rather than a soft one. The mechanism is in [why modular programmes run shorter](/blog/why-modular-programmes-run-shorter).
Against that, a change made after fabrication begins costs more than the same change made during design, for reasons set out in [changing a design after fabrication starts](/blog/changing-a-design-after-fabrication-starts).
What to do with this
Resolve the site items before the feasibility is finalised, because they carry the largest uncertainty and they are knowable with an investigation rather than an assumption.
Then treat specification as the adjustable variable, since it is the one that can move without changing the programme or the planning position. That sequence produces a number that holds, which is the whole purpose of the exercise described in [how HVM changes a development feasibility](/blog/how-hvm-changes-a-development-feasibility).
MADEmodular / MADEbetter.
MADEmodular / MADEbetter.