Exterior rendering of Unit 27, seafront development

    Sustainable Design

    Unit 27 – Prefabricated luxury micro-flats for the cities of the future

    A 27-square-metre modular housing system that frees up outdoor space and re-establishes direct contact with the urban and natural landscape.

    2018 · Modular housing · Sustainable Design

    Living in 27 square metres without compromising on quality: a modular unit for the cities of tomorrow

    Over the next hundred years, cities will become increasingly dense, leading to two converging problems: homes will become ever smaller and open space (both private and public) will shrink until it disappears. Unit 27 was created to provide a design solution to both issues, overturning the logic of compact living: not squeezing life into fewer square metres, but radically rethinking what is needed inside and what can remain outside, restoring space to the landscape and to human relationships.

    The housing unit measures 27 square metres and contains everything necessary for a full daily life: a kitchen with a dining table for six people, a multifunctional sofa-bed, a bedroom with an all-in-one unit featuring four large drawers under the bed and a pull-out side wardrobe concealed within the headboard, and a full bathroom with a separate toilet and double shower. The separation between the living and sleeping areas is provided by a screen wall that incorporates a double-sided holographic television, visible from both sides of the home. The space does not feel cramped thanks to two specific design choices: the open-plan layout without rigid partitions and the large windows that open up the view of the surrounding landscape.

    The single module is designed to be freely stacked vertically within a steel frame structure, featuring large balconies and terraces. The outdoor space (both private and communal) can be freely organised by residents with vegetation and furnishings, to facilitate social interaction and reconnect with nature and the urban landscape in temperate climates. Thanks to its small footprint, Unit 27 can be installed in residual spaces within urban areas; larger clusters create built ecosystems where compact, well-organised dwellings, pleasant outdoor spaces and vegetation strike a balance.

    The ideal users are young couples or singles who cannot afford larger, more expensive accommodation but do not wish to compromise on high-quality living space in an urban context. The prefabrication of the module allows for reduced construction times and rigorous quality control of components, whilst the system’s modularity enables the project to be scaled from a single unit to a garden block of flats. Unit 27 is not a compromise on the quality of space: it is a design gamble on the idea that living in fewer square metres can mean living better, if the design frees up space for the landscape and relationships.

    Renders & Photos

    Exterior rendering of Unit 27, seafront development
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    Exterior view of the Unit 27 modular complex in a coastal setting, featuring green terraces and shared spaces opening out onto the landscape.

    Technical specifications

    Year
    2018
    Client
    Project research
    Typology
    Modular housing, prefabricated micro-flats
    Area
    27 square metres per unit
    Status
    Concept – design research
    Designers
    Barberio Colella Architects
    Publications
    Rethinking The Future, re-thinkingthefuture.com/landscape/6305-unit-27-by-barberio-colella-architetti

    Technical drawings

    Axonometric view of Unit 27 construction system
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    An axonometric view illustrating the construction system of the unit: stratigraphy, load‑bearing structure and bioclimatic design of the building envelope.

    How do you design a sustainable housing unit when space is limited and urban density is increasing?

    Urban growth demands ever-increasing density, but the current response (mini-flats assembled without any environmental strategy) results in housing with energy consumption disproportionate to its floor area, no effective natural ventilation and zero connection to the outside world. The problem is not merely aesthetic: it is climatic and social. Unit 27 demonstrates that modular prefabrication and bioclimatic design can coexist even within 27 square metres. The open-plan layout with large windows maximises passive ventilation and natural light, the green terraces act as a thermal buffer and a space for socialising, and the steel frame allows for the disassembly and reuse of components. Here, sustainability is not just a label: it is the principle that shapes the design.

    Frequently Asked Questions

    The open-plan layout, free of rigid partitions, allows cross-ventilation between the large windows on opposite sides of the unit. The module’s design and the ratio of glazed area to internal volume are calibrated to maximise natural air exchange without the need for mechanical ventilation in the shoulder seasons. The external terraces act as climatic transition zones, reducing direct exposure to the sun during the hottest hours and promoting passive cooling.

    Factory prefabrication reduces on-site waste by 50–70% compared to traditional construction, limits the transport of materials to the site, and allows for rigorous control over the quality of assembly, which results in a more airtight and high-performance building envelope. The steel frame is designed for disassembly: at the end of its life, the modules can be removed, refurbished or recycled without destructive demolition. It is a circular approach to residential construction.

    Each unit occupies a 27 m² footprint, but vertical stacking on a steel frame allows for significant housing density without saturating the site. The space saved is reclaimed for green terraces, communal gardens and vegetation, permeable surfaces that contribute to rainwater management and the reduction of the urban heat island effect. The project demonstrates that densification does not mean overbuilding, provided the relationship between built-up and green areas is designed as a system.

    Vegetated terraces have a measurable bioclimatic function: they reduce the surface temperature of structures exposed to the sun (by up to 20°C compared to a bare surface), act as additional thermal insulation, and contribute to the evaporative cooling of the surrounding air. In a cluster of Unit 27 modules, the green terraces distributed across the various levels create a cooler, more humid microclimate that reduces the need for mechanical cooling in the dwellings.

    Yes, the modularity and prefabrication make Unit 27 scalable for social housing projects: costs are predictable, construction times are reduced, and build quality is guaranteed by the industrial process. The flexible modularity allows the project to be adapted to plots of different sizes, whilst the communal terraces and shared green spaces create the conditions for a sense of community that traditional public housing rarely fosters.

    Generic prefabricated modules replicate the logic of a shipping container: a closed, standardised volume, with no relation to the climatic context or the external space. Unit 27 is designed by architects with expertise in bioclimatic design: the orientation of the windows, the ratio of glazed area to thermal mass, the position of the terraces and the permeability of the frame are design choices that influence indoor comfort and energy consumption. The difference lies between an industrial product and a prefabricated architectural project. ---

    Are you considering a sustainable residential project on a modular or neighbourhood scale?

    Unit 27 demonstrates that sustainability and quality of living can coexist even in compact spaces. If your project requires an integrated approach (prefabrication, bioclimatic design, smart densification) we can work together to find the most suitable solution.

    Let’s talk about your project

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