The advantages of semi-collective housing result from their specific architectural attributes and possibilities of solving urban problems: the transition between different urban tissues, renewal of urban forms, rational limits of density. The presence of transitional spaces, stores, density, and formal diversity gives these assemblies a high adaptability degree to different urban contexts. Due to the intimate relationship with the natural environment, the presence of green spaces (half public spaces, for common use and private outdoor spaces, planted patios and gardens), and to their formal configurations, the semi-collective housing ensembles, in the characteristic form of a relatively new type of habitat, located between the individual and collective, can be successfully used in the development of ecological urban planning and architecture (as proven by numerous examples performed on the base of these principles). Environmental design of housing approach involves consecutive levels, under the same imperatives, but with priorities and challenges which require differentiated solutions: at the ensemble level, at the dwellings group level and at the dwelling itself. This paper aims to present several ways of combining architectural, urban and economic qualities, specific for semi-collective urban housing with those obtained by an ecological design approach and to identify some solutions that can bring, with minimal efforts, significant energy gains [ABSTRACT FROM AUTHOR]