Imagine a jacket intelligently designed to adapt to various situations: weight gain and loss, casual and formal occasions, the changing seasons of the year. Instead of owning multiple coats, you would need only one versatile piece. Housing can—and should—be designed in the same way. Yet most dwellings are created for a single, static household type, ignoring the fact that households evolve.

The housing debate focuses on numbers (100,000 homes per year, 1 million by 2030, etc.) because the underlying assumption is simple: the shortage is a problem of insufficient supply, therefore the solution is to build more and faster. But what if the crisis is not simply an issue of numbers, but of design as well? 

Here in Europe, many cities already contain enough residential floor area to satisfy the demand for housing and yet still fail to meet that need. The housing crisis is in part a result of the way residential space is usually organized. Significant housing capacity remains locked within large, underoccupied or inflexible dwellings. For example, according to Eurostat, a third of the EU population lives in an underoccupied home—a dwelling considered too large for the needs of its household. Better, more flexible housing design could unlock this latent capacity. 

Increasingly, housing is conceived as a market product rather than as social infrastructure. Floor plans are little more than three-dimensional translations of Excel spreadsheets, rigid and standardized, while society is more diverse and dynamic than ever: blended families, boomerang children, older people living alone, empty nesters, shared households, single-person households, separations, young adults struggling to find housing.

People are forced to perform all kinds of spatial contortions to accommodate their changing needs within rigid, standardized dwellings, often resorting to improvised and inadequate solutions: balconies are enclosed to gain extra space; dwellings are subdivided without fully complying with regulations or without creating fully autonomous units; homes are shared by multiple households despite never having been designed for cohabitation, compromising privacy and sometimes resulting in overcrowding or domestic tensions. Meanwhile, in an effort to cut costs, dwelling sizes are systematically reduced without rethinking their layouts—as if a smaller dwelling were simply a reduced version of a larger one.

When housing design ignores inhabitants’ realities, dwellings become obsolete. As households change, people are forced to move—not because their homes are too small, but because those homes no longer meet their needs. 

If dwellings had versatile, adaptable floor plans and spatial strategies, many households could remain longer in the same home and even create additional homes without building more. The need for new housing could be reduced. Good housing design not only improves everyday life; it also increases the capacity and resilience of housing stock. 

The floor plan is the most powerful tool we have to improve housing. Through years of research into contemporary ways of living and evolving household needs, my firm, STAR strategies + architecture, developed a set of adaptability principles that were implemented in our collective housing project START-Ivry in Greater Paris. The project brings together social, intermediate, and controlled-market-rate housing. By introducing circularity at the scale of the dwelling, these principles help reduce the need for new housing without increasing construction costs or floor area. The six housing design strategies presented below translate these principles into practical spatial solutions that enable homes to evolve alongside changing households.

The Super-Versatile Two-Bedroom Flat

Most two-bedroom flats are designed for a single, static kind of household. In reality, they often end up accommodating several types: parents and an adult child, flatmates sharing, a senior living with a student or caregiver, a couple renting out a room.

Standard layouts rarely support these situations. Poor privacy and spatial organization make cohabitation stressful, discouraging these living arrangements and pushing inhabitants to seek separate dwellings—often at a higher financial cost—thereby increasing housing demand.

Yet a well-designed two-bedroom unit can comfortably accommodate two households through a few simple spatial mechanisms: clearly separated nonadjacent bedrooms with visual and acoustic privacy, one located near the entrance and designed to accommodate a future kitchenette; and two compact bathrooms. In such a configuration, two households can comfortably share a dwelling while maintaining a high degree of autonomy. An intelligent floor plan can prevent the need for an additional home. 

The Divisible Home: Unlocking Hidden Housing Capacity

This key principle concerns larger dwellings. Homes with three or more bedrooms often become underoccupied once children leave. Parents remain in houses that no longer correspond to their needs, yet moving out is difficult due to emotional attachment to the home and its neighborhood, financial constraints, or simply a lack of suitable alternatives.

Divisible homes are designed to anticipate the functional, technical, and legal requirements of future subdivision. The owner keeps their space, while the unused section becomes a small dwelling for a young adult child, a future caregiver, or to generate rental or sale income to supplement retirement.

This simple strategy is economically, socially, and environmentally sustainable: an additional dwelling appears in the housing stock without building additional floor area. This activates latent housing capacity. Had homes built over the past four decades been designed this way, today’s housing shortage would be considerably smaller.

The Reconfigurable Space: Small Changes, Big Impact

Sometimes, all a home needs is one additional room to continue meeting the changing needs of its inhabitants: the arrival of a newborn, working from home, caring for an aging parent, or a child staying on weekends.

To achieve this, we developed several spatial mechanisms that make it possible to create that additional room without moving home. One is the “plug”: a closable balcony that can become a habitable room of about 100 square feet. Another is the “modular living room,” organized longitudinally along the façade rather than in depth, with at least two windows, two radiators and two lighting and electrical points, allowing part of the space to be separated into an additional room. In some cases, we also introduced the “relocatable kitchen” (when the kitchen still had its own room—increasingly rare in today’s dwellings), allowing it to move to the living room and freeing space for an additional room. In every case, the functional, technical and legal requirements are anticipated as part of the design.

“Co-Residence”: Rethinking Shared Living

Shared living is often associated with students or temporary accommodation. However, when designed well, it can offer an effective response to the growing number of one-person households. With this objective in mind, we developed a new shared housing typology in 2012, which we call co-residence. Each resident has a private unit—including a generous bedroom and an en suite bathroom—while sharing the kitchen, living and dining areas. It is designed to accommodate between three and six residents.

Compared with six separate flats, a co-residence for six residents can reduce both floor area and energy consumption by up to 45%. More important, it creates social networks and mutual support, which are essential for many who live alone. Unlike co-living, with its hotel-like character and large-scale communal spaces, this model operates at the intimate scale of the domestic dwelling—offering privacy without sacrificing community. 

The PLUS Typology: Beyond the Bedroom Count

Housing types are typically defined by the number of bedrooms. Yet an increasing number of households fall between these categories: single parents, divorced parents with shared custody, or home workers; they need extra space, but the next “bedroom category” dwelling feels too large and unaffordable.

To address this, we developed the PLUS typology: a new housing category positioned between the conventional ones. Its defining feature is the PLUS space: a compact space open to the living room, with a window and fully equipped. It is compact yet large enough for sleeping or use as a workspace. For example, if a one-bedroom unit is 460 square feet and a two-bedroom unit is 670 square feet, then a one-bedroom PLUS unit is approximately 560 square feet. The aim is to approximate the performance (quality and usability) of the next housing category without adding the full extra surface area, so that the home meets additional needs while remaining affordable—particularly for more vulnerable households, such as single parents.

The PLUS typology aligns housing size with the real spatial needs of households, demonstrating that a few carefully designed square feet can significantly reduce the need for many more.

Compact Dwellings: Make Every Square Foot Count

Many single-person households struggle to find affordable housing. This is partly due to reluctance to reduce dwelling sizes, despite the rapid growth of smaller households across Europe.

A compact home can offer an excellent quality of life, provided it is carefully designed. Compact dwellings require intelligent design, well beyond current standards, to make the most of every square foot. The smaller the home, the smarter its design must be.

To achieve this, we developed several strategies: highly optimized floor plans with precisely positioned doors, windows, and radiators; higher ceilings that allow mezzanines; and an intelligent modulation of ceiling heights according to use. Together, these strategies can reduce a home’s floor area by 25% to 40% without compromising quality of life. We also design these homes to be groupable, allowing several units to be combined over time as household needs evolve. Compact, well-designed dwellings are not a compromise, but a strategy: they provide a more suitable and affordable response to small households by aligning floor area with actual needs and they reduce the built surface and its associated environmental and economic costs.

How Better Housing Design Can Lower Public Costs

When we consider the combined effect of these six strategies, we estimate that they could reduce the need for new housing by around 40%. The precise figure may be debated, but the principle cannot. Yet none of these strategies requires new technologies, higher construction costs, or larger spaces. Quite the opposite: They simply demand better-designed floor plans.

So why does the housing sector keep overlooking this? Perhaps it’s time for other sectors to help drive the improvements housing so urgently needs. Indeed, the impact of poor housing design extends far beyond the sector itself. When housing no longer responds to the needs of its inhabitants, it can negatively affect educational outcomes, intensify domestic tensions, cause household fragmentation, or force seniors into care facilities. Poor design can also hinder entrepreneurial initiatives and force households to move frequently, disrupting education, employment, and local communities. A well-designed floor plan can lower public expenditure by supporting more stable living environments and improving long-term social, economic, and environmental outcomes.

The Role of Design—and the Role of Architects

There is, however, a structural obstacle to implementing these principles. In the current housing production model, design is largely shaped by developers and their standardized layouts. Too often, architects are brought into the process only after the key decisions about the floor plan have already been made, making them little more than facade decorators. As a result, floor plans are optimized for short-term efficiency rather than long-term adaptability. 

Standardization and prefabrication are increasingly presented as the solutions to the housing crisis, but more poorly designed housing that can be built faster is not a long-term solution. Ill-designed dwellings risk locking an entire generation of housing into layouts that will become obsolete as household structures evolve, perpetuating the cycle of shortage.

A New Narrative for Housing: Focusing on People, Not Spreadsheets

The six strategies presented here create housing that is more flexible, resilient, and capable of evolving alongside changing households. Such homes are not only a major social achievement; they can also significantly reduce the demand for new housing and lower public expenditure. The best part: these homes are not more expensive (our construction costs were about $165 to $183 per square foot, excluding VAT , at 2019 prices) and don’t require larger spaces or new construction methods.

However, the prevailing production narrative—“produce more at a faster rate instead of fewer that are well-designed”—serves those who profit from the ongoing housing shortage. As one developer once asked me: “Why all this effort to improve housing, Beatriz? We sell everything, no matter how bad it is.” Designing housing that adapts to people, increases social resilience, and reduces the need for new construction is not a utopia; it’s both a real possibility and a collective responsibility.

We have demonstrated that housing can be both a social infrastructure and financially viable. Ignoring the first means betraying one of housing’s fundamental responsibilities. A new narrative is urgently needed, one that adapts housing to real needs, not just to spreadsheets. Quickly building millions of poorly designed homes is like mass-producing millions of ill-fitting jackets: no matter how many we make or how quickly we produce them, they will still fail to meet people’s needs, forcing them to look for another option.

Featured image: photo by Nicholas-Grosmond.  All other images courtesy of the author.