BUENOS AIRES — Nathanaël Abeille had long been interested in natural light, perhaps because of how little of it reached the sun-starved street he used to call home in Paris, France. But then, about five years ago, the designer and graduate of the prestigious Arts et Métiers ParisTech stumbled upon an idea — one that came, quite literally, in a flash.

Neighbors from across the way had opened their window. The glass caught the sun and, through an accident of angles, reflected the light directly into Abeille's apartment. Ding! That got his mind buzzing as he considered different ways to reflect sunlight from one surface to another.

The young Frenchman was working at the time for the architect's studio Jean Nouvel, specializing in designing printed glass facades like the ones used for the Imagine Institute building in Paris. Little could he have imagined that years later, his know-how would make an impact an ocean away, in Buenos Aires.

There's another, almost cosmic dimension to the project.

Abeille arrived in the Argentine capital in 2013 as part of an exchange program for designers. Through local architect Francisco Ribero and publicist Cecilia Fortunato, who were working on a project involving ecological tiles, he then discovered the Villa 21 sector of Barracas, in south-east Buenos Aires. Like in Paris, the area's alleys are often in shadow. But unlike in France, Abeille realized, the bricks used to make buildings here are often left visible, not covered up. That's when he got another idea: To make reflecting bricks by covering them with a thin metallic coat.

Abeille and his partners created a prototype by using the high vacuum metallizing process, where a vacuum chamber removes all air from pores inside the brick while covering it with the metallic coat. First they tried an aluminum coat, then opted for a chrome-nickel alloy. The latter "sticks better to the brick and confers more surface hardness, and physical and chemical resistance," says Carlos Muniagurria, a specialist who helped Abeille and his colleagues make the bricks.

The research continued for some years, including tests with cement bricks and ceramic coating. The designers also had to consider costs. The result was two lines of products: ordinary bricks that were glazed; and a special kind of ceramic tiles, which they then tested out on a busy street in Villa 21.

As a trial run, they fixed the tiles to a surface area of just two square meters. "That's the minimum you need to generate a line of sunshine in the street alongside pedestrians," says Ribero, the architect. The aim now is to increase the reflected surface to 45 square meters and 1,000 ceramic tiles, with financing from Ideame, a crowdfunding initiative.

"The idea of reflecting light to make full use of it is not new," says Abeille. "The ancient Egyptians did this with polished metals to light up the interior of pyramids, and for the Greeks, it was a defensive weapon to blind their enemies at war."

For Ribero, there's another, almost cosmic dimension to the project. "For us in the Southern Hemisphere, sunlight comes from the north, but reflection will make it shine from the south itself," he says. "There's something almost poetic in this."