The only windows at this concrete house in Moreira, Portugal, face one another across recessed patios.

Designed by Portuguese studio Phyd Arquitectura, the two-storey House in Moreira is closed to its surroundings. "It seems to me that this idea of drawing a house that is 'closed' to the outside works quite well," architect Paulo Henrique Durao told Dezeen. "We call the project Home Turtle, as it has a tough outer shell and a soft interior."

The entrance to the house cuts into the corner of the reinforced concrete volume and features a wooden door that stands out against the otherwise grey facade.

Inside, rooms are laid out on a comb-shaped plan that wraps around the two small terraces.

Three bedrooms are located on the first floor, which steps back at the centre to allow high ceilings and a double-height window in the living room below. "We proposed a very closed project, so we had to offer something really special to the client," said Durao.

A wooden staircase connects the two floors and the treads extend further along the walls to become shelves. "We are interested in the transformation of one element into another," explained Durao.

To ensure the house receives enough natural light, the architect designed a series of small skylights to perforate the roof.

Marble was selected for the flooring at ground level, while upstairs the floors are wooden.

Phyd Arquitectura previously designed a bunker-like house near Torres Novas, which had a similar concrete exterior.

Other Portuguese residences on Dezeen include a house with a hole in its facade and a blackened timber house on a hillside.

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Photography is by Javier Callejas.

Above: axonometric diagram

Above: ground floor plan - click above for larger image

Above: first floor plan - click above for larger image

Above: section - click above for larger image