Earthquake-resistant construction: what the NSR-10 requires for your house
We are YU Construcciones S.A.S., a construction company based in Armenia, Quindío, a high seismic hazard zone. Since the earthquake of 10 August 2026, the question we hear most is how to tell whether a house is well built. This guide explains what the code requires for a home and what you can check without being an engineer.
It is general guidance, not a structural assessment. Only an engineer who inspects the building, the drawings and the soil can say whether a particular structure is safe.
What the NSR-10 is
It is the Reglamento Colombiano de Construcción Sismo Resistente, Colombia's earthquake-resistant building code. It is mandated by Law 400 of 1997 and implemented through its regulatory decrees; it is called NSR-10 because it was adopted in 2010, and it has been amended since. It applies to new buildings throughout the country, and also when an existing one is extended, modified or strengthened. For a house, the titles that matter most are:
- Title A, general requirements, including the classification of municipalities by seismic hazard.
- Title H, geotechnical studies.
- Title E, one- and two-storey houses.
- Titles C, D, F and G, by material: structural concrete, structural masonry, steel structures, and timber and guadua (a native bamboo).
- Title I, technical supervision.
Why it matters so much in the Coffee Region
The NSR-10 classifies municipalities into low, intermediate and high seismic hazard zones. Quindío and Risaralda are in the high zone. The region has seen the proof: the earthquake of 25 January 1999 destroyed much of Armenia, and the magnitude 7.4 earthquake of 10 August 2026, centred near San José del Palmar (Chocó), damaged buildings across the Eje Cafetero (Coffee Region) once again.
The country's first seismic code dates from 1984, so many houses in the region were built without it, and others were later extended without a design. On top of that there is the ground: almost every plot is on a hillside, many of the soils formed on volcanic ash, and there are two rainy seasons a year.
What the code requires for a house
- Soil study. Title H governs geotechnical studies. Its scope depends on the building and the ground, and it determines the foundations. On a hillside it also guides the cuts, the retaining structures and the drainage; see slopes and retaining walls.
- Structural design. For most buildings, drawings and calculations signed by a qualified engineer with a current professional registration.
- The simplified method of Title E. For one- and two-storey houses, within the limits set by the code itself, the NSR-10 allows the full structural analysis to be replaced by prescriptive rules: how the foundations are built, how much length of confined wall is needed in each direction, where the confining columns and beams go and how openings are treated. It simplifies the design; it does not eliminate it: the house still needs drawings, a permit and someone with technical training to check the rules. If the house does not fit within those limits, it is designed with the general method.
- Building permit, whose processing includes a review of the structural design; see the building permit, step by step.
What you can check without being an engineer
- Foundations that come from the soil, not from habit. Ask what foundations your house has and which study they are based on. On a hillside, retaining structures and drainage are part of the house's safety, not an extra.
- Confining columns and beams. In a confined masonry house, the structural walls are framed by reinforced concrete columns and beams: at the ends, at the corners, where walls meet, and at the level of each floor slab and of the roof. A free-standing wall without that frame does not behave the same way in an earthquake.
- Walls in both directions, distributed in a more or less balanced way. A completely open façade, with no walls or frames to compensate, is a weak point.
- Openings are not improvised. Opening a door in a structural wall or removing a wall to enlarge the living room changes how the house behaves. That is for an engineer to decide, not the foreman.
- Storeys are not added without a design. A house calculated for one storey is not built to carry another, even if the columns look thick. An extra storey is an extension: it requires assessing the structure, often strengthening it, and a permit.
- Quality concrete and steel. The concrete must have the strength shown on the drawings, and the normal practice is to take samples on site for laboratory testing. The reinforcing steel must be deformed (ribbed) bar with a quality certificate, placed as shown on the drawings.
- Supervision during construction. For a house the law does not always require independent technical supervision, but it is advisable for an engineer to check the steel before each pour: what ends up inside the concrete can no longer be inspected.
Bahareque and older houses
Bahareque — a frame of guadua and timber covered with earth or mortar — is part of the traditional architecture of the Coffee Region. The NSR-10 provides for bahareque encementado (cement-rendered bahareque) in new one- and two-storey housing, with its own requirements. An old bahareque house was built without those requirements, and its condition depends on how it has been maintained: damp and insects deteriorate the guadua and the timber without it being noticeable from outside.
The same applies to brick houses built before the code or without a design. An old house is not necessarily unsafe, but you cannot tell by looking at it. Before buying, remodelling or extending one, an assessment by a structural engineer is advisable. If it calls for strengthening, the strengthening is designed, the permit is obtained and the work is carried out according to the design. See earthquake damage repair and strengthening.
What to ask of whoever builds for you
- The signed structural design and the soil study it is based on.
- The building permit and the approved drawings.
- A responsible engineer on site, identified by name.
- Photographic record of the foundations and the steel before each pour.
- The test results for the concrete, when samples are taken.
- A written contract with specifications, not just a price.
That is how we work: construction under the NSR-10, a resident engineer, regular reports with a photographic record, and payments against records of verified progress. Technical direction is led by Ing. Diego Luis Arango Jaramillo. See structures and foundations and consulting and estimating.
Warning signs
- “The foreman does it without drawings; he knows what he is doing.” A good foreman's experience is valuable, but it does not replace a design or the soil study.
- “We'll add a storey later.” Leaving bars sticking out of the slab is not the same as designing for two storeys.
- “We'll get the permit later.” A project without a permit has also had no review of its structural design.
- Savings on what cannot be seen: less steel than the drawings call for, thinner columns, concrete mixed “by eye”.
- A price per square metre without seeing the plot. We explain why in what drives the cost of building a house.
Frequently asked questions
If my house came through the 2026 earthquake undamaged, does that mean it meets the code?
Not necessarily. It is a good sign, but every earthquake is different, and having
withstood one does not guarantee how the house will respond to the next. What gives
certainty is an assessment.
Does a one-storey house also have to comply with the NSR-10?
Yes. For such houses there is the simplified method of Title E, provided the house
falls within its limits.
Can I build the second storey later on?
Yes, if the house is designed from the outset for two storeys and the second is built
with a permit. If it was not designed that way, the structure has to be assessed and
probably strengthened. Designing from the start for the storey to come usually works
out cheaper than strengthening later.
How much more does complying with the code cost?
We do not give a percentage: it depends on the house and the plot. The structure is the
part of the works that cannot be corrected later without breaking things open: it is
where it makes least sense to save.
Do you have questions about a house you are going to build, buy or extend? Write to us with a few photographs and the municipality, and we will tell you what is worth checking first.