Who does not dream of expanding his living space? If you live in a country house or town, adding an extra room is an attractive project. What are the guidelines to follow, how to proceed, the main configurations...
Add an extra room to a house: what are the possibilities?
Simple authorization or building permit?
Before you start a detailed construction plan, check the feasibility of your project and consult the Local Plan of Urbanism or Plu of your city (in town hall). This indicates whether the zones are buildable or not. When your land is buildable, it's a good point. It is then necessary to study the possible easements of sight and distances to be respected for any new implantation.
In a second step, check the surface of your project.
- Between 6 and 20 m² extension, a prior authorization is sufficient.
- Since 1 January 2012, a preliminary declaration of work is sufficient for an extension of up to 40 meters. Under the following conditions: the work must be undertaken on an existing construction, the land must be located in an area covered by a local urban plan and the land must be located in an urban area.
If these conditions are not met, a building permit is required for any extension of more than 20 m²
- When the extension brings the total area of the building to more than 170 m², the intervention of an architect is mandatory and a building permit.
- Up to 5 m² additional area, no authorization required: toilet, shower room.
The main types of extension for a house
The contiguous extension consists in extending an existing building. The new building communicates with the old and can be conceived on one or two levels. In this case, it is necessary to modify the opening systems and to create transit solutions.
The elevation seeks to gain space in height. It is ideal for expanding city dwellings. It is an expensive solution that requires a lot of technicality. A high-rise job requires solid foundations and the intervention of many tradespeople.
excavation is more rare. It consists in gaining space in depth, to transform a cellar into a guest room for example. It is particularly suitable when the basement is
semi buried and has a source of natural light.