In Colombia, the structural design of a building is done by a civil engineer qualified under Law 400 of 1997, following the NSR-10, Colombia's seismic-resistant building code (A.1.3.4). It is delivered as signed structural drawings and calculations, which go with the building permit application together with the geotechnical study (A.1.5). If the lot allows more than 2,000 m² to be built, Law 1796 of 2016 also requires a revisión independiente (independent structural design review / peer review).
What steps does a structural design follow?
The NSR-10 sets them out in twelve steps for new buildings (table A.1.3-1):
- Preliminary sizing and coordination with the other professionals.
- Evaluation of the final loads: self-weight, dead and live loads, wind and settlement.
- Seismic hazard level and the site's Aa and Av values (look them up here).
- Design earthquake ground motions, with the soil and the occupancy group (design spectrum).
- Structural configuration and structural material.
- Degree of irregularity of the structure and analysis procedure.
- Seismic forces.
- Seismic analysis of the structure.
- Lateral displacements.
- Story drift check.
- Load combinations.
- Design of the structural members.
What must the structural drawings contain?
- The material specifications, such as the strength of the concrete and steel or the quality of the masonry, and where in the structure each one goes.
- Size, location, dimensions and reinforcement of every structural member.
- Precautions against volume changes in the materials, such as cambers.
- The location and magnitude of prestressing forces, if any.
- Connections and splices and, in steel structures, surface cleaning and corrosion protection.
- The energy dissipation capacity the seismic-force-resisting system was designed for.
- The live loads and finish loads assumed in the calculations.
- The building's occupancy group.
They are signed or embossed with a seal by the civil engineer acting as the responsible structural designer, and they must be the same ones used on site (A.1.5.2 and A.1.5.2.1).
What is the calculation report?
It is the document that explains how the design was done. It must describe the structural system and record the gravity loads, the energy dissipation capacity, the calculation of the seismic force, the type of analysis and the check that the drifts were not exceeded. If software was used, it must explain the principles of the model and the input data; the program's output may go in an appendix, but on its own it is not the calculation report (A.1.5.3.1).
What is a "calculista estructural"?
It is what the structural designer is called on site: the civil engineer who calculates the structure, signs the drawings and the calculations, and answers for them. The NSR-10 presumes that every element shown on a drawing or in a calculation report complies with the code, and holds the professional who signs it responsible for the design (A.1.5.1).
Which structural documents go to the curaduría?
| Document | Who signs it | Reference |
|---|---|---|
| Geotechnical study | Qualified civil engineer | A.1.3.2 and A.1.5.4 |
| Architectural drawings, with occupancy group and performance level of the nonstructural elements | Licensed architect | A.1.3.3 |
| Structural drawings | Civil engineer, structural designer | A.1.5.2.1 |
| Calculation report | The engineer who did the structural design | A.1.5.3.1 |
| Independent review statement, if the lot allows more than 2,000 m² | Reviewer independent of the designer | A.1.3.7 and Law 1796 |
What is needed to start, and how long does it take?
Architectural drawings, a geotechnical study and a topographic survey. The architectural design must state the use of each part, its occupancy group and the performance level of the nonstructural elements (A.1.3.3). As a reference, at DDES a five-story building usually takes four to six weeks of design, and a twenty-story tower three to four months, depending on how far along the architecture is.
What determines the cost of a structural design?
The area, the use, the number of floors, the structural system and the soil. With the architectural drawings and the location of the lot, DDES sends a fee proposal at no cost. Before that, you can check with the Law 1796 assistant whether your project will need an independent review.
Source: NSR-10, Title A, sections A.1.3 and A.1.5; Law 400 of 1997; Law 1796 of 2016.
Frequently asked questions
Who can sign a structural design in Colombia?
A civil engineer qualified under Law 400 of 1997 (A.1.3.4). They sign or emboss with a seal the structural drawings and the calculations, and answer for the design (A.1.5.1 and A.1.5.2.1).
Can the analysis software's output serve as the calculation report?
Not on its own. The NSR-10 allows it to be appended, but requires an explanatory report covering the structural system, the loads, the energy dissipation capacity, the seismic force, the type of analysis and the drift check (A.1.5.3.1).
How long does a structural design take?
It depends on the size and on how far along the architecture is. As a reference, a five-story building usually takes four to six weeks, and a twenty-story tower three to four months.
