Screens of concrete panels surround Block Wall House, a triangular home that design studio Nendo has nestled into a forest in Japan.

Located in Japan's Nagano Prefecture, the home has a long triangular form extending 110 metres along the side of a road, which winds through the forested landscape.

Nendo has screened the house from passing traffic by enclosing it in walls of concrete blocks, but positioned gaps between them to preserve views of the lush surroundings.

"Ensuring privacy and offering a sense of openness while living in the interior space are generally conflicting goals," the studio told Dezeen.

"In this project, however, we tried to achieve both through the design of the enclosing walls, aiming for a house that is completely surrounded by these walls."

To form the screens, over two thousand small concrete blocks were set within a horizontal concrete grid at a range of angles, creating varying levels of light and privacy in different places. In areas where additional privacy is required, there are two rows of blocks.

"In areas with a single row, the view is set in one direction," the studio explained. "With two rows overlapping, the view on the other side is visible only when the block angles in the front and back rows align, otherwise, the view is obstructed," it continued.

"From the public road, the house appears to be hidden by these walls, but once inside, one can enjoy the lush green surroundings," added Nendo.

The blocks are made from CO2-SUICOM, an alternative to traditional concrete designed to emit less CO2 during its production, according to Nendo.

"The material used for the blocks is CO2-SUICOM, which is made by replacing a portion of cement with an industrial byproduct and adding a carbon dioxide-absorbing material for less CO2 emissions during production," the studio explained.

Inside, Nendo has arranged the home's living spaces in timber structures slotted between the rows of screens.

"This design creates a spatial experience that leads people further inside, giving a sense of space that feels larger than the actual area," said Nendo.

It comprises a living room, dining room, bedroom and bathroom, all of which are united by moody, dimly-lit interiors finished with dark colours and textured materials.

This includes wooden floors, ceilings and columns, alongside rough concrete elements and dark grey furnishings, such as a bench that wraps around the edges of the living room.

Founded in 2005 by chief designer Oki Sato, Nendo is a Japanese studio most known for its product design work.

Previous architectural projects by the studio include an archive building formed from stacked concrete tunnels and a showroom for a marble brand that features a dimpled marble facade.

The photography is by Takumi Ota unless stated otherwise.