Dark limestone walls form a low-lying pool house that runs alongside this chemical-free swimming bath in Edmonton, designed by architecture studio GH3.

Located inside Borden Park, a community park in Edmonton, GH3's bath includes a large swimming pool, a children's pool and a pool house for changing and equipment.

All the water in the Borden Park Natural Swimming Pool is filtered using plants, layers of gravel and sand, instead of machinery and chemicals. This makes the project Canada's first chemical-free outdoor swimming pool, according to the studio.

GH3 chose the material for the pool house to draw on this filtering process, creating a gabion wall constructed of dark limestone and steel. It describes the structure as resembling a "filter-like" barrier. The pool house's slender and low-lying form also draws on the style of an existing mid-century modern building built on the site in the 1950s.

"These extant buildings connect the new with a century-old cultural heritage of architecturally distinctive, civic outdoor bathing pavilions," GH3 said in a project description.
Most of the older structure was demolished but the studio maintained a portion to house electrical equipment, machinery for cleaning sand, as well as pool apparatus like umbrellas and furniture.

The stone walls of the pool house are punctured with tall dark steel doors that lead into several changing bays.
Inside, a stained marine-grade plywood lines the ceilings, covers the floors ...