Named the Refuge, the project is a walled pavilion containing a square building and swimming pond – a swimming pool with a natural filtration system.
"Instead of designing a swimming pond alongside the garden pavilion, we designed a garden pavilion which integrated the swimming pond within its perimeter – a refuge," said Bert Rogiers and Pieter Vandeputte, founding architects of NWLND Rogiers Vandeputte.
"The result is an extraordinary set of spaces that are sound in concept and in detailing, a series of rigid and curved lines that generate a playful intimacy."
The architects used red concrete both to contrast with the green landscaping and to reference the nearby brick house.
To create a dialogue between the house and the Refuge, bricks left over from the construction of the house were reused as border walls for the patio and overflow filter pond.
The interior of the pool house, which is also red, is lined with plywood formwork panels that were soaked in pigment from the concrete during the setting process.
"Instead of discarding these plywood panels after demoulding, the nails were taken out and the panels were gently cleaned," the architects told Dezeen.
"They are then used as a finish for the insulated inner shell of the pavilion."
Rogiers and Vandeputte enclosed the swimming pond, pool house, and underground studio space within the solid concrete walls of the pavilion.
According to the architects, building the entire project in concrete meant the swimming pond did not have to be lined.
Cutouts in the solid concrete walls were located to frame views of the landscape. The concrete roof of the pool house extends over an outside patio and curves around the pavilion.
"We always look for the dematerialisation of a project, especially by limiting the different materials used. Concrete is a very good material for this," said the architects.
"Concrete can be transformed into any shape, especially if the contractor is specialised in this and collaborates with us to find innovative solutions."
The curved cutout in the pool house roof joins with the perimeter of an enclosed garden in the landscaping to form a complete circle.
"The circle is used as a visual language for the abstracted version of a clearing in the forest," said the architects. "Every frame that arises throughout the space engages in a dialogue with the existing house and nature."
NWLND Rogiers Vandeputte is an architecture studio founded by Pieter Vandeputte and Bert Rogiers in 2017.
Other projects using coloured concreted on Dezeen include a pink concrete holiday home in East Sussex by RX Architects, a peach-coloured pavilion that overlooks a peach tree field in Henan Province, China, and a red concrete golf clubhouse in the Algarve, Portugal, designed by RCR Arquitectes.
The photography is by Johnny Umans.
Architect: NWLND Rogiers Vandeputte
Structural engineer: Util
Landscape: Jeroen Provoost
Concrete contractor: Patrick Janssens Festoo, Festoo Constructs
Windows: Allaert Aluminium