Located in Barrio León, in a humble series of blocks of single-family semi-detached houses, the site was first completely cleared in order to make way for a residential project that is closely interwoven with modern-day concerns. To solve the problem of privacy in low-rise semi-detached houses, the façade of Casa Castillo is a neutral, grey and secretive plane that can nonetheless surprise with its occasional openings. The ground level develops gradually and smoothly. Small variations in level articulate the different spaces without destroying the overall sense of unity. Refusing from day one to adhere to the oppressive parameters of municipal building regulations, the architects exceeded minimums wherever possible in order to provide the house with its own external area - an extension of all the internal spaces which unexpectedly multiplies the size of the house. Conceived with the extreme heat of the Andalusian summer, the flat roof is equipped with a small swimming pool.