Interventoría (independent construction oversight on the owner's behalf) is the control carried out by an independent professional, on the owner's behalf, so that the works are built according to the drawings, specifications and codes, at the agreed quality, schedule and cost. The NSR-10 defines the interventor as the civil engineer, architect or builder who represents the owner during construction, and states that the role includes quantity take-offs and may extend to administrative tasks (A.13). Technical supervision, which the law does require depending on the area, is one part of interventoría (A.1.3.9.4).
What does an interventor do?
- Technical control: quality of materials and workmanship, compliance with the specifications, and approval of each activity before it is paid.
- Administrative control: site meetings, minutes, site log, insurance bonds and schedule tracking.
- Financial control: quantities, payment certificates, change orders and contract balance.
- Handover and close-out: acceptance of the works, manuals, bonds and close-out report.
Interventoría or technical supervision?
The NSR-10 deliberately uses the term technical supervision: the commentary to its Title I explains that the word interventoría was avoided because of its connotation of auditing money, and that technical supervision can be part of interventoría. Supervision checks that the structure and the nonstructural elements are built according to the drawings; interventoría controls the whole contract. The same professional can do both (A.13), as long as they are independent of the contractor.
| Interventoría (oversight) | Technical supervision | Independent design review | |
|---|---|---|---|
| What it controls | The whole construction contract: quality, schedule, cost, quantities and payments | That the structure and the nonstructural elements are built according to the drawings, designs and specifications | The structural designs: model, calculations and drawings |
| When | From the start of the contract to its close-out | During construction, before every concrete pour | Before the building permit is issued |
| Independence | Represents the owner before the contractor | Independent of the contractor (Law 400 of 1997, art. 37) | Someone other than the designer, with no employment relationship with the designer |
| Is it mandatory? | The NSR-10 does not require it: the owner or the contract decides | Yes, if the lot allows more than 2,000 m² (Law 1796), and for occupancy groups III and IV whatever the area (A.1.3.9.1) | Yes, if the lot allows more than 2,000 m² (Law 1796) |
| What it delivers | Monthly reports, progress and quantity minutes, close-out report | Release forms, materials control and a final report for the Certificado Técnico de Ocupación | Comments report and signed review statement for the curaduría |
When is interventoría mandatory?
The NSR-10 only makes technical supervision mandatory: Law 1796 of 2016 requires it when the lot allows more than 2,000 m² to be built, and Law 400 of 1997 requires it for buildings in occupancy groups III and IV whatever the area (A.1.3.9.1). Full interventoría is the owner's decision on a private project; on public contracts it is set by public procurement rules. If the interventor is also going to sign the technical supervision, they must hold a professional license and have more than five years of experience in structural design, construction, interventoría or technical supervision (I.3.2.1 and I.3.2.2).
What should an oversight report contain?
Physical and financial progress against the schedule and the budget, the quantities executed, the test results, the nonconformities and how they were closed, the change orders with their technical opinion, and the photo record. On the Ébano building, for example, DDES delivered twenty-four oversight reports, reviewed thirty-two progress statements and controlled the concrete with an external laboratory, delivery by delivery.
How long does interventoría last?
As long as construction, plus the close-out: acceptance, bonds and contract close-out. On phased projects the oversight covers each phase; at Altos de Solemio, DDES has provided oversight of phases 1 to 6 since 2021.
What determines the cost of interventoría?
The length of the works, the level of presence required (full-time or scheduled visits), the size and complexity of the project, the number of simultaneous work fronts, the tests to be controlled and the administrative and financial scope the owner asks for. With the construction contract and the schedule, DDES sends a proposal for scope and fees.
See the construction oversight service, the technical supervision service and the Law 1796 assistant.
Source: NSR-10, Title A (A.1.3.9 and A.13) and Title I; Law 400 of 1997; Law 1796 of 2016.
Frequently asked questions
What is interventoría (construction oversight)?
It is the control carried out by an independent professional, on the owner's behalf, so that the works are built according to the drawings, specifications and codes, at the agreed quality, schedule and cost. The NSR-10 defines the interventor in chapter A.13.
Is interventoría mandatory in Colombia?
The NSR-10 only makes technical supervision mandatory, and it is one part of interventoría: when the lot allows more than 2,000 m² to be built (Law 1796) and in occupancy groups III and IV. On private projects, full interventoría is the owner's decision; on public contracts it is set by public procurement rules.
Can the interventor also do the technical supervision?
Yes. The NSR-10 allows it (A.13), as long as the professional is independent of the contractor and meets the supervisor's requirements: a professional license and more than five years of experience (I.3.2).
