Most of the passive design guidance in circulation was written for temperate latitudes, and a surprising amount of it is actively wrong at 0° latitude. Kampala sits within half a degree of the equator. The sun passes almost directly overhead at noon, all year, and the day length barely varies. That has three consequences.
1. Horizontal shading works, and it is easy
Because the midday sun is close to vertical, a modest horizontal overhang shades a north or south facade completely through the middle of the day. You do not need the deep, calculated brise-soleil that a 40° latitude building needs on its south face. A 900–1200mm eave does most of the work.
2. East and west are the whole problem
The morning and afternoon sun comes in low and horizontal, and no overhang stops it. This is where the cooling load actually comes from. The options are: don't put glass there; put vertical fins there; or put a solid served space — stair, store, plant, circulation — on the east and west ends and give the habitable rooms north and south.
The third option is the cheapest and the most reliable, and it is the one we reach for first.
3. There is no heating season to trade against
In a temperate climate, shading strategy is a compromise: you want summer shade and winter sun. Here there is no winter. You can shade aggressively year-round with no penalty. Designers trained on temperate rules often under-shade out of an instinct they no longer need.
The ventilation half
Kampala's altitude — around 1,200m — means night-time temperatures drop into the high teens most of the year. That is a real resource, and it is wasted by sealed buildings.
- Single-banked plans, one room deep, so every space cross-ventilates
- Openings high and low: low inlets for occupant-level airflow, high outlets to purge hot air
- Secure night ventilation — louvred and grilled openings that can stay open safely after dark
- Exposed thermal mass in the ceiling to store the coolth the night air delivers
Humidity is the limit
Honesty about this: passive strategies handle temperature well here and humidity poorly. In the wettest weeks, air movement is the only lever, and there are buildings — theatres, some laboratories, data rooms — where mechanical dehumidification is not optional. Passive design gets the base case right and shrinks the plant. It does not always eliminate it, and claiming otherwise does the approach no favours.
