The key difference
| General contractor | Several contractors | |
|---|---|---|
| Contracts | one | as many as there are trades |
| Who coordinates the work | the general contractor | the client or their project manager |
| Responsibility for the deadline | one party | split; each is responsible only for their own part |
| Disputes between trades | resolved by the general contractor | resolved by the client |
| Price | includes coordination and a risk margin | may look lower, but the coordination is your time |
| Warranty | one point of contact | a separate one for each trade |
When a general contractor pays off
- there is a hard opening date — a shop in a shopping centre, for example;
- the work involves many building systems that have to be coordinated with each other;
- you do not have your own construction project manager;
- other tenants are working on the site, or it stays in operation;
- you want one point of contact and one warranty.
When separate contractors can work
- the job is small and simple — one or two trades;
- you have an experienced project manager who coordinates the work day to day;
- the deadline is flexible;
- you already have a good long-standing relationship with specific tradespeople.
Where the hidden costs arise
With several contractors, the most expensive part is usually not the work itself but the interfaces between trades: who is responsible for the hole in the wall for the ventilation duct, who closes up the ceiling after the electrician, who waits while someone else finishes. Every idle day or piece of rework stretches the timeline, and none of the contractors has to answer for it.
A general contractor takes on these risks and prices them in. If the price and the risks need to be visible, we use the Open Book model, where all costs and the general contractor's fee are transparent.
How ITTU works
ITTU acts as general contractor: building works and building systems in one programme, with one person responsible for the project from proposal to handover. After handover, we can continue to look after the site under a service contract, because we know the systems from having installed them.
Updated 03.10.2026 · ITTU