Casa LLP is a minimalist residence located in Barcelona, Spain, designed by Alventosa Morell Arquitectes. This building has been designed after the request, of two sisters, for a bioclimatic house where to live together and independent at the same time. So the project focuses on these clients’ needs. The building plot enjoys views over the Collserola mount, and it is on a uniform and deep pitch. After the bioclimatic study of this exact point we decided the strategies of the project, in order to maximize the environmental and thermal performance, and to follow the equivalent demands to a passive house.