Buildings that know where they are

Buildings are designed according to their context. Each generation inherited a knowledge of its territory refined by trial and error —how thick the wall, which way the window faces, how deep the eaves— without ever speaking of bioclimatics or thermal transmittance: they built with the climate. Today we run simulations to arrive, often enough, at conclusions those communities had already found without a single equation. Simulation does not replace that knowledge: it verifies it, quantifies it, and lets us apply it to buildings tradition never had to solve, such as a housing tower on an arterial avenue.

A good deal of the bioclimatic literature is written for climates with seasons —summers that demand cooling, winters that demand heating. The tropics work differently. Here the climate does not change with the calendar but with altitude: in Colombia you can move from the humid heat of the Pacific to the cold of the high plateau, and each thermal floor holds its conditions practically constant 365 days a year. Designing well in the tropics is not designing for the seasons; it is designing for one very specific climate, all the time.

Four climates, four bodies of wisdom

Resolution 0194 of 2025 from the Ministry of Housing recognises this reality and zones the country into four climates: cold, temperate, hot dry and hot humid, each with its own baselines and required savings. What is interesting is that Colombian vernacular architecture had already solved, empirically, the problem of each one:

Cold climate (high plateaus). Rammed earth and Cundiboyacense adobe are pure thermal mass: walls 40 to 60 cm thick that absorb the day’s radiation and give it back at night, small openings, compact plans and courtyards sheltered from the wind. The problem was never the heat: it was keeping it.

Temperate climate (coffee-growing slopes). The bahareque of the Coffee Cultural Landscape answers a benign but rainy climate: lightweight walls that breathe, eaves and verandas that shade and shelter from the rain without closing the space off, and moderate cross ventilation. An architecture of thresholds.

Hot dry climate (inter-Andean valleys, inland Caribbean, La Guajira). Thick earth walls and light colours that damp down the day’s heat, and the courtyard that cools with vegetation, shade and water. Latticework that lets the wind through but not the sun, and in the Wayuu ranchería, enramadas where shade and breeze do all the work.

Hot humid climate (Pacific, Amazon). With permanent humidity, thermal mass is the enemy and everything turns on moving air: raised stilt houses that catch the breeze, light and permeable envelopes, high steep roofs that shed the rain and push the hot air out. The maloca is that principle taken to its fullest expression.

Four climates, different bioclimatic strategies: conserve heat, temper, damp down and evaporate, ventilate. No one solution serves the other three, and that is the first lesson of the tropics.

What intuition already knew

Empirical knowledge can now be verified with a set of tools.

The Givoni psychrometric chart: a graph that plots, hour by hour, the 8,760 hours of a typical year for the place according to temperature and humidity, and overlays the comfort zone together with the passive strategies capable of bringing outdoor conditions closer to it.

What the chart shows for Bogotá is this: a cold climate 79% of the year, where only a minimal fraction of the hours falls naturally within comfort, and where the recommended strategies are passive solar gain and making use of internal heat gains. Which is exactly what the rammed-earth house of the high plateau had been doing for centuries.

The second is the adaptive model of the ASHRAE 55 standard, conceived for naturally ventilated spaces, which is what housing in Colombia is. Unlike comfort models for air-conditioned buildings, the adaptive model recognises that people are not thermostats: we put on a jumper, open the window, move about, and our comfort range shifts with the outdoor temperature we are used to.

It determines the range in which roughly 80% of occupants feel comfortable, and for the tropics this is fundamental, because it validates what vernacular architecture always assumed: comfort is not imposed with machines, it is negotiated with the climate.

The map of adaptive opportunities

Cross the chart, the adaptive model and the site conditions and you get a repertoire of decisions about form, grouping and envelope for the project’s specific climate. For the cold climate of the high plateau, that map looks like this:

Compact plan with wind protection. Less exposed envelope means less heat loss; sheltering the volume from the wind reduces infiltration, the main night-time leak.

Rooms grouped adjacently. Spaces that share walls warm each other and concentrate internal gains instead of dispersing them.

Attached building without blocking sun or ventilation. Neighbouring volumes act as a wind barrier, provided the siting looks after solar access and air flow.

Envelope with thermal inertia. Materials with mass that store the day’s heat and release it at night: the contemporary version of the rammed-earth wall.

Smooth, neutral façade surfaces. Medium reflectance that stabilises the wall temperature without sacrificing the solar gains that are desirable in this climate.

Controlling losses through the openings. The window is the thermal weak point: a window-to-wall ratio close to 25% balances light and solar gain against losses through the glass.

Shading elements calibrated to the solar path. Protections that block the sun only during the hours of risk and allow gain the rest of the time.

Note something: none of these strategies is a product. They are decisions of architecture —form, orientation, grouping, proportion of openings, materiality— and that is why they cost little or nothing when they are taken in time. Simulation exists precisely so they can be taken in time: so we know, before building, how many hours of comfort each decision delivers and which ones are not worth their cost.

Beware of imported solutions

Just as vernacular wisdom was local, modern mistakes tend to be imported. Systems arrive on the market that sound innovative and come backed by extraordinary performance which, in climates with seasons, is adaptable and transformative. Simulated under tropical conditions, the story changes.

In a climate of moderate, constant swing such as Bogotá’s, comparative simulations show that tightening the transmittance of the walls can translate into barely a few dozen additional hours of comfort a year —minutes a day— in exchange for significant extra cost per dwelling, more dead load on the structure and effects on the construction schedule that, in cases such as social housing, compete with access to housing itself.

On top of that, those layered systems were conceived for dry climates or for continuous heating that dries the construction out. In our high, sustained relative humidity, their residual cavities become points of permanent condensation: sources of mould and fungus that degrade the finishes and, worse still, compromise indoor air quality and the health of the occupants.

None of this is an argument against innovation; on the contrary, it is a call to research from within architecture, with local data, before adopting. The middle ground is collaboration between low tech and high tech: assessing strategies with the site’s climate file, verifying their hygrothermal behaviour and quantifying how much real comfort they deliver and at what cost.

Designing with the climate, not against it

The tropics give us something seasonal climates do not: stability. A building well designed for its thermal floor works well every day of the year —but only if the design starts from the project’s climate. At 57UNO that is our work: we build the climate file for the place, develop the bioclimatic diagnosis, simulate thermal, daylight, ventilation and energy behaviour from the siting through to the interior of the unit, and support compliance with Resolution 0194. That is how we make the architecture itself the building’s main environmental conditioning system, as it always was.

If you are developing a project and want to know which strategies genuinely make sense in its climate —and which are just imported noise— let’s talk. That early diagnosis is usually the most profitable investment in the whole project.