Case nel Verde, a nZEB class building in Apulia

"Case nel Verde" is a highly sustainable residential building located in Puglia, 30km north of Bari and together with "Case di Luce" built in 2016, it regenerates an abandoned urban area. It is the largest residential complex built of hemp; the use of this material allows the subtraction of CO2 while greatly reducing the ecological footprint. The two buildings, through the use of hemp in their construction, have subtracted about 100,000kg of CO2, a value comparable to the CO2 subtracted in 20 years by 2,000 trees. The building is part of a urban regeneration project of a degraded area. This Area is closes to the railway and in the past was a manufacturing area but after the residential expansion in the 1980s, it was abandoned. “Case nel Verde” is a seven floor’s building with a parking basement and 26 houses on the upper floors; at the ground floor there are a commercial spaces. The houses are divided into three different types: urban villas, flats and penthouses, eachone with a different relationship with the outside space. The project develops two research themes in the Mediterranean context: the first related to the experimentation of passive bioclimatic contributions in the summer period through a cross-ventilation inside the building; the second related to housing typology through the application of typical villa characters in the idea of wanting to build a new typology: "the urban villa." "Case nel Verde" is a project that combines innovation and tradition in conceptual and construction aspects. In the design phase, It’s reused the “patio villa” typology, typical of Mediterranean architecture, to reinterpret it and inserting it within an "in-line building". The research stems from the desire to respond to new needs of the real estate market by pursuing the idea of "new lifestyles." Thus was born the "urban villa" an apartment characterized by having a greenhouse-garden that filters the entrance to the house from the landing. The house is then developed all around the double-height loggia that, through panoramic windows constitute a continuum between indoor and outdoor spaces in perfect symbiosis between "Nature and Architecture." Solar radiation is regulated by a sunshade, positioned at a height calculated by analysis solar diagrams, to permit the solar intake in the winter period ad the reflectance in the summer months. Innovation and tradition is also combined in the bioclimatic features, with the use of the ventilation tower of Arab memory, rather than in the use of materials: lime, a material used since Roman times, meets an inert vegetable, hemp, shavings giving birth to a carbon-negative building material that in this project is combined with other natural materials giving birth to a residential complex of healthy apartments with very high living comfort. The study of solar exposures, analysis of dominant winds and control through fluid-dynamic analysis led to the experimentation of a "passive summer system" obtained through a complex ventilation system inside the building. The distribution landings on each floor are transformed into "horizontal ventilation channels", the stairs in line become "baffles", the vertical cavity is a true "internal ventilation tower" with intake on each floor and a draught opposed to the penthouse floor. The system, almost as if it were a "lung", makes it possible to obtain, in the area of the landings, a mitigated thermal gradient in summer, useful for reducing, through the exchangers, the temperature inside the flats. While having "a natural soul," the building reinterprets contemporary architectural styles with Mediterranean language. The architectural composition is made by "subtraction"; the pure block of the building is "excavated" by the double-height loggias constructing a “full-empty" system, seemingly random, stitched together by cork stringcourses and bio-wpc sunshades. The ground connection on the street front remains full and unified, resolving the accesses to the ground floors’s spaces, filtered from the street through small flower beds with fat plants. On the internal side, the building establishes an intimate relationship with the natural element; the architecture, on the one hand, "digs in", exposing the "framework" of the double-height pillars and revealing the mosaic block on the ground floor, and on the other hand, it "lifts up", allowing itself to be penetrated by the garden, losing two floors in favour of relaxation and play areas for the condominiums; this area is characterised by an architectural sub-language, marked by a suspended volume and a Kandinsky-style composition of paving, flower boxes and benches. The construction of "Case nel Verde" pays great attention to environmental ethics, as it reduces CO2 right from its construction technique. The usual criterion of building with consumption of primary resources is transformed into a criterion of building with consumption of annual plants, thus moving from the "crater city" to the "forest city”. The building's shell is made of hemp brick, a natural biocompound of hemp wood and lime, with high thermo-hygrometric, eco-compatible and recyclable properties, as well as being a material with a negative CO2 emission balance, capable of capturing and sequestering 60 kg of CO2 from the atmosphere for every m3 of material. The building has a very low energy demand and is in "class A4 nZEB" , also obtained the "Certificate of Environmental Sustainability - Protocol Itaca Puglia 2017" with the remarkable score of 3.7.