A Unified Framework for Daylighting in Tropical Art Galleries: A Simulation-Based Validation of a Six-Category Design Hierarchy for A Gallery Bay in Port Harcourt, Rivers State, Nigeria

Tropical art galleries are caught in an old argument that never quite gets settled: how do you let in enough daylight for visitors to enjoy the space without slowly ruining the very artworks they came to see? Most daylighting guidance was written for temperate, overcast climates, so it simply doesn't hold up under equatorial sun. This study builds and tests a six-part framework for tropical galleries in Southern Nigeria, one that treats climate, building envelope, shading, interior surfaces, conservation needs, and everyday operational realities as parts of a single connected system rather than separate design choices. Using Radiance and pyradiance simulations on a real gallery bay in Port Harcourt, Rivers State, four linked studies tested each variable on its own and then together. No single fix solved both problems at once. Shading and glazing calmed the glare near windows, dropping peak illuminance from 2,355 to 1,478 lux, while brighter interior surfaces and a north clerestory pushed daylight deeper into the room, more than doubling illuminance there from 175 to 410 lux. But each of these improvements quietly undid the other's gains. Only when combined did the design actually work both ways: a lower peak near the windows (1,352 lux) than shading alone achieved, and nearly double the deep-room daylight (610 lux) of any single strategy. That combined effect, stronger than the sum of its parts, is the heart of what this research shows. It also found that shading rules borrowed from cooler climates simply don't hold near the equator, where north-facing windows can still catch unwanted sun for part of the year. Even so, the best version of the design still let in six to thirty times more light than conservation standards allow everywhere on the gallery floor, meaning vitrines and case-level shielding are still essential to protect the art. The findings offer validated, quantitative guidance for architects and conservation professionals designing daylit galleries in tropical developing-country contexts. The result is practical, tested guidance for architects and conservators building daylit galleries in tropical, developing-country settings.