Apollo Architects & Associates has designed a family home with a walled-in garden that houses two generations under one roof and aims to blend indoor and outdoor living.

Tokyo-based architecture studio Apollo Architects & Associates replaced an existing home in Japan's Kanto region with a two-storey building designed to emphasise the connection between the interior and the garden.

Located in a quiet residential neighbourhood, Noble House and its garden are surrounded by a tall, concrete wall that aims to create the feel of an "inner world".

"The house is facing three different sides," Apollo Architects & Associates founder Satoshi Kurosaki told Dezeen.

"In order to ensure security and privacy, we surrounded it with tall, board-formed concrete walls to create an 'inner world.'"

Trees from the previous garden were kept as a part of the new landscape design, while added species were scattered throughout the space to create a diverse garden.

"We tried to inherit the memory of the old house by incorporating the magnificent pine tree and podocarpus tree which was in the Japanese garden of the original house, adding more trees to create a fuller landscape," Kurosaki said.

Constructed over two levels, the home was designed to separately house two generations under the same roof. It has an open atmosphere that connects the gardens with the house's interior through a fully glazed south-facing elevation.

"Openness was one of the key themes in creating unity among the two-generational home positioned over separate floors," Kurosaki said.

"We wanted them to enjoy the same scenery in their everyday lives. Thus the design was developed with continuity and its intermediate region in mind."

The ground floor of the home is dedicated to the client's mother and contains a large open-plan living-dining space, a bedroom and a bathroom, all of which are adjoined by terraces.

A tatami room and study space are also found on the ground floor and are accessed off the shared entrance.

Large floor-to-ceiling windows stretch the length of the space and provide views out to the gardens.

Exposed wooden beams line the ceiling and matching dark wood flooring was used for the interior.

A large veranda and terrace extend into the walled garden and employ a similar dark wood material palette to further blend the exterior with the interior.

"I believe that intermediate regional styles of the interior and exterior are the most attractive parts of Japanese spaces," Kurosaki said.

"In Noble House, we made a spacious space with eaves, depth and a broad veranda, and used materials to create a mood that continues to the outside."

The upper floor, designed for the younger generation, overlooks the garden and is enclosed within a long balcony and a glass-roofed interior courtyard that encourages outdoor living.

Two bedrooms are located at the front of the home and adjoined by a south-facing terrace.

A walk-in closet and shared bathroom are organised around a glazed terrace at the rear of the design, allowing light to filter into the staircase and auxiliary spaces.

Apollo Architects & Associates is a Tokyo-based studio and was founded by Satoshi Kurosaki in 2000.

It has previously completed a metal-clad home with a centrally planted courtyard, as well as a steel-clad home with an "exterior living room".

Photography is by Masao Nishikawa.