Technical supervision

The building is built the way it was designed.

Photo: Josué Isaí Ramos Figueroa / Unsplash

DDES provides supervisión técnica independiente (independent technical supervision required by Law 1796 of 2016) in Colombia, required when the lot allows more than 2,000 m² to be built. Before every concrete pour it checks on site that the structure is built according to the drawings and the NSR-10, and it delivers the final report for the Certificado Técnico de Ocupación (CTO).

Code: NSR-10
Deliverables: 5
Coverage: Nationwide (Colombia)

What is independent technical supervision?

It is the verification that the structure is built according to the structural designer's drawings, designs and specifications, and that the nonstructural elements meet their seismic performance level (NSR-10, A.13 and Title I). It is done by a licensed professional with more than five years of experience, independent of the contractor (I.3.2).

Independent technical supervision checks on site that the structure is built according to the drawings, the specifications and the NSR-10. Law 1796 of 2016 makes it mandatory when the lot allows more than 2,000 m² to be built, whatever the use, and it is the basis of the Certificado Técnico de Ocupación. We are on site at the moments that matter: before every concrete pour.

How do interventoría, technical supervision and independent review differ?

Source: NSR-10 (A.1.3.7, A.1.3.9, A.13 and Title I), Law 400 of 1997 and Law 1796 of 2016.
	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

Does your project need it? Check it with the Law 1796 assistant.

Before the pour, we check

Reinforcement, lap splices, concrete cover, anchorages and formwork are checked member by member. Nothing is poured without the supervisor's written release.

Materials control

Concrete cylinders at 7, 14 and 28 days, slump on every truck and mill certificates for the steel. We keep the strength statistics and give early warning when something does not comply.

A record that backs the works

Site log, visit reports, monthly reports and a signed final report. A complete file for the owner, the curaduría and the Certificado Técnico de Ocupación.

What is the process?

Drawing review
We study the drawings and calculations and point out what will be hard to build.
Supervision plan
Visits, tests and hold points agreed in writing.
Inspection
Reinforcement and formwork checked before every concrete pour.
Testing
Cylinders, slump and steel mill certificates.
Final report
Signed record for the Certificado Técnico de Ocupación.

What do we deliver?

Supervision plan
Release forms before every concrete pour
Statistical control of concrete strength
Monthly reports
Final report for the Certificado Técnico de Ocupación

What we check on site

Concrete strengthDesign f′c at 28 days

Cover in a marine environment50 mm or more

Reinforcing steelfy 420 MPa

Slump± 25 mm of the specified value

Story drift≤ 1.0 % of the story height

Required by law. Law 1796 of 2016 requires technical supervision independent of the contractor when the lot allows more than 2,000 m² to be built.

Law 1796 of 2016 · NSR-10

What does the law require for your project?

Move the area, the floors and the use. The building changes with you, and we show you who has to sign it.

Law 1796

Signatures on file

Milestone 1 · Permit
Milestone 2 · Structure
Milestone 3 · Occupancy

Photo: Ray Donnelly / Unsplash

Why

What the curaduría will ask you for

Who signs your project

DesignsStructural engineerSigns the drawings and the structural calculations.

ReviewsIndependent reviewerLaw 1796Separate from, and independent of, the designer.

ApprovesCuraduría urbanaIssues the building permit.

SupervisesIndependent technical supervisorLaw 1796Independent of the contractor, from the first concrete pour.

CertifiesCertificado Técnico de OcupaciónLaw 1796Signed by the supervisor; without it the building cannot be occupied.

Frequently asked questions

Does my project need technical supervision?

If the lot allows more than 2,000 m² to be built, Law 1796 makes it mandatory, whatever the use. Smaller projects are not required to have it, but it is the cheapest way to avoid mistakes that cost a lot later.

How often do you visit the site?

According to the supervision plan we agree on at the start. At a minimum we are there before every pour of structural members, and at critical stages the visit is daily.

Can the contractor supervise its own work?

No. The law requires the supervisor to be independent of the contractor. That independence is what gives the certificate its value.

What is the Certificado Técnico de Ocupación?

It is the document in which the independent technical supervisor certifies, under oath, that the structure and the nonstructural elements were built according to the drawings and the NSR-10. It is recorded before a notary, and without it the building cannot be occupied.

When should supervision start?

Before the first concrete pour. The foundation is the first thing checked, and what was not supervised cannot be certified afterwards.