The contiguous extension is the most frequently used constructive solution, as long as we have sufficient ground to implement it. It allows to extend the house quite easily and can be envisaged on one level or with stage to be wedged on existing heights.
It usually involves creating or modifying the openings to ensure the inner connection between the new and the old volume. According to the margin of freedom left by the Local Plan of Urbanism (PLU), one will be able to choose to stick to the existing architectural framework or to stand out from it.
An example of a side house extension
Here, a project of extension of 30 m2 realized in 2012 by the studio Bureau de change in London. The intervention consisted of bringing together two terraced houses in one dwelling. The extension at the back of the two houses serves as a link between the two buildings. Styled like a large living room , the ground floor opens onto the back garden and now consists of a kitchen center around which revolve a lounge and a dining room.
After the work, the living space of the house went from 250 to 280m2. The cost of the intervention is 350 000 €, but it includes both the construction of the extension and the total renovation of the two terraced houses.
This radical solution is, however, more and more often implemented in cities, where urban density requires turning to the sky to gain living space . The elevation is to add one or more levels to an existing build.
Obviously quite expensive because it assumes access difficulties, either by its height or simply by the storage constraints of materials such as work equipment. It also implies certain precautions of implementation, in particular to make sure that the existing construction is strong enough to support an elevation, and if necessary to provide a reinforcement of foundations. In any case, it is also important to ensure the lightness of the new structure, which is why most of the elevations are made of wood framing .
An example of a home extension by elevation
In this project located in the heart of Paris in the district of Ménilontant, the architect Philippe Berthomier has completely deconstructed the sloped roof of this old artisan workshop, to build a real extra floor. A cube of 50m2 covered with zinc in which is arranged a parental suite. Slightly removed from the first two levels, the project has resulted in a pleasant balcony along the new structure. Realized in a few months, the works also included the complete renovation of this house finally invested by the owners in the summer of 2012. If the whole site was 370 000 €, the work of elevation is 150 000 €.