The table of agents
| Agent | Essential function | Practical note |
|---|---|---|
| Promotor (developer) | Drives, programmes and finances the works | Jointly and severally liable towards purchasers |
| Proyectista (designer) | Drafts the design | Qualifying degree depends on the building's use |
| Constructor (contractor) | Executes the works | Takes on material execution and its subcontractors |
| Director de obra (works director) | Directs technical and planning aspects | In housing, an arquitecto |
| Director de la ejecución (execution director) | Controls construction qualitatively and quantitatively | In housing, an arquitecto técnico |
| Control entities and laboratories | Verify quality | Act on design, materials and execution |
| Product suppliers | Manufacture and supply | Answer for the conformity of what they supply |
| Owners and users | Conserve and maintain | Duty of use and maintenance per the building logbook |
Three articles develop the figures with the most practical weight: the developer and their obligations, the pair formed by the architect and the technical architect, and the contractor with its subcontracting chain. All three are read together, since their responsibilities overlap on site.
The logic of the distribution: every risk with an owner
The LOE does not distribute roles by guild tradition but by risk management: each function carries a liability, and each liability a warranty period. The designer answers for design errors; the contractor for execution defects and, exclusively, for the finishing defects of the first year; the site direction for its direction and control functions; the developer for everything towards purchasers, jointly and severally, precisely because the developer chooses the others and sells the result.
This design explains two features of the system that surprise those arriving from other frameworks. First: liability is articulated by damage and periods, one, three and ten years depending on the nature of the defect, more than by generic contractual breaches. Second: the central position of the developer, who cannot hide behind delegation, turns the selection of the other agents into their most important risk decision.
Separate directions, controlled works
The most marked Spanish singularity is the duality of the dirección facultativa (the design team's site direction): the works director directs the development of the works in their technical, aesthetic, planning and environmental aspects in accordance with the design, while the execution director takes on the verification of product reception, the control of material execution and its economic valuation. Two technicians, two function sheets, two signatures on the key documents. The daily mechanics of that collaboration, and its typical frictions, are developed in the article on the distribution of functions between architect and technical architect and, on the site side, in the one on works direction and execution direction.
Economic reading of the agents chapter
For the budget, the table of agents translates into three cost blocks worth estimating early: the technical fees for design and direction, today free and negotiable; the cost of quality control, with its entities and laboratories; and the insurances, with the ten-year damage policy as an obligatory item in housing and each agent's liability policies as a cost embedded in their prices. Overall, a usual order of magnitude for the complete technical block sits between 8 and 15 percent of the PEM (presupuesto de ejecución material, the direct construction cost) depending on size and complexity, an indicative figure each operation must check.
Frequent errors
The first is the occasional developer who ignores being one: whoever builds for themselves and later sells assumes the developer's liabilities even without considering themselves one. The status of developer follows from the facts rather than from intention.
The second is confusing the two directions and asking one for what belongs to the other, a classic source of control gaps on site. The split of functions is spelled out in the appointment contracts.
The third is hiring agents on price without looking at solvency and insurance: paper liability is worth whatever the assets or the policy backing it are worth. The policy and its validity are worth checking before signing.
The fourth is forgetting the silent agents: suppliers and laboratories also answer, and their documentation, markings, certificates, test reports, is what sustains any later claim. That documentation is gathered during the works rather than at the end.
Note: the percentages cited are indicative and vary with building type and complexity; the regime of agents and liabilities is that of the consolidated LOE.