An exposed concrete grid delimited the extension of a small existing house and served as structure for its expansion. Porous brick walls intentionally arranged in the grid respond to different necessities of solar protection and privacy. Two steel structure pavilions added additional services to the house.
The house is located close to Brasília´s city centre in a neighbourhood called Lago Sul (South Lake), surrounded by detached houses facing short public streets that end up in “cul-de-sacs”. The previous owner of the house had planned to build a bigger one with 350sqm and two stories high. Instead, due to funding problems, he decided to build all the foundations of the house and only use it partially in a 150sqm, one story construction. He built the extra floor plan and covered it with a ceramic tile roof. Moreover, he sold the house without never going ahead with the expansion plan.
Some of the most valued features in the neighbourhood are the big size of its lots, its proximity to the city centre and the fact that the area is almost exclusively residential, which in Brasilia, is well appreciated. The value of the land often surpasses the price of the existing constructions, making it very common for people to buy old houses only to demolish them in order to make space for building new ones. The intention here was to build a bigger house in the same lot with a budget that was 35% lower than what was expected for a brand new construction. The idea to lower the final cost of the construction was to take advantage of the existing structure and re-use part of the existing walls.
The area occupied by the previous construction was not enough to fit the new program. Therefore, a new concrete grid created to expand its structure, create extra space and defined the outside casing. Due to the lack of regularity in the existing foundations, columns and beams, the new grid follows an “imaginary” pattern of growth inspired by the irregularity of the existing structure. It sits on both existing and new foundations and uses columns with two different sections: 40x40cm and 40x15cm.
The new grid works as a graft, connecting old walls and new ones and supporting the additional program of the extension. Porous brick walls intentionally arranged in the grid respond to different necessities of solar protection and privacy. The strategy resembles the one used in the Oscar Americano House by the Brazilian modernist architect Oswaldo Bratke (1907-1997). Two steel structure pavilions added additional services to the house such as a garage, an outdoor kitchen and a sauna.