Engineering the future: Public toilets are the invisible infrastructure our cities still badly need

Toilets rarely make headlines unless you remember that  infamous scene in Trainspotting. In everyday life, most people only notice them when they need them and find them missing, closed or unusable. 

At that moment, the priorities of urban design become brutally clear. Beautiful public squares, cultural programming and carefully curated retail suddenly matter far less than the location of the nearest functioning cubicle. 

Public toilets are one of the simplest tests of whether a place works for people, yet their provision is quietly shrinking. Freedom of Information data requested by Age UK from London’s local authorities in 2025 revealed that nearly 100 public toilets had closed over the previous decade, while only 32 new facilities opened. Across many cities, a piece of essential public infrastructure is steadily  disappearing.

Older visitors, families with young children and people with medical conditions often plan journeys around the availability of toilets

For some people this is a minor inconvenience. For others it determines whether they feel able to leave home at all. Older visitors, families with young children and people with medical conditions often plan journeys around the availability of toilets. Remove them, and the city becomes less accessible. 

The problem with invisible infrastructure

Public toilets in some ways mirror building services more broadly: when they work well, nobody notices them.

Ventilation, lighting, water systems, acoustics and controls quietly shape how spaces feel and perform, yet they rarely appear in glossy project photography. They become visible only when something goes wrong.

Toilets are perhaps the most immediate example of this invisible infrastructure. When they are poorly ventilated, poorly lit or badly maintained, the experience deteriorates quickly. 

Small facilities, complex systems, large impact

From an engineering perspective, public toilets are far from simple. Designing these facilities often requires infrastructure sized for event-scale demand, compressed into some of the smallest buildings within a project.

Few building types experience such extreme patterns of use. Facilities that sit almost empty early in the morning can suddenly serve thousands of visitors within a few hours. Systems must therefore be designed for peaks rather than averages, handling intense demand while remaining efficient during quieter periods.

Ventilation, drainage, durability and maintenance access all become critical. These are spaces that must withstand constant turnover of occupants, heavy cleaning regimes and years of hard use while continuing to perform reliably.

Environmental conditions matter too. Good lighting improves safety and comfort. Effective ventilation maintains air quality in confined spaces. Acoustics can determine how dignified a space feels to use.

Individually these details may seem minor, but together they influence the everyday experience of public places and can make a significant difference.

This becomes clear in practice. At Camber Sands Welcome Centre on the Sussex coast, facilities must accommodate up to 25,000 visitors during peak periods. Designing systems capable of handling that level of demand requires careful consideration of peak loads, resilience and operational efficiency.

A small building quietly supports the success of a much larger destination

In quieter cultural settings, such as the gardens of the Dulwich Picture Gallery, accessible and family-friendly facilities simply allow visitors to stay longer and enjoy the space more comfortably.

In all cases, a small building quietly supports the success of a much larger destination.

Professional responsibility

If basic infrastructure is missing, it is difficult to argue that a place has been successfully designed. Through relationships with local authorities, developers, and stakeholders, design teams can highlight gaps in provision and make the case for including public infrastructure as part of both large-scale schemes and smaller one-off projects, alongside other essential civic infrastructure.

There is a practical argument too. Without essential amenities, people shorten visits and avoid places. This has a direct impact on footfall and dwell time, and therefore overall commercial success of a space.  

If we want to create places that are genuinely inclusive and usable, we need to reconsider what we prioritise. These are not secondary considerations, but the systems that allow places to function at all.

Public toilets may be the most honest spaces in architecture. And cities work best when they are treated that way.