Architecture involves problem-solving. Typically it means maximising comfortable space for cost in housing or office projects yet when it comes to designing for incarceration and the judicial system, there are other factors at play. Many of the usual rules still apply – prisoners should receive ample natural light, for example – but they are also being punished, so how should a person’s wellbeing be balanced with paying penance? We explore best practice in the design of prisons, police stations and courthouses in search of some arresting architecture.

The Criminal Justice Centre in Muttenz is a unique complex where a 47-cell prison, the public prosecutor’s office and court of justice all sit under one roof. Kunz and Mösch Architekten had to plan the building to ensure judges and prisoners never cross paths (not to mention ensure top levels of security). But the firm also had to squeeze all of this into a narrow slice of land between the street and railway tracks.

“The building was designed to give this new neighbourhood in Muttenz a focal point and a simple architectural language,” says architect Philipp Kunz of the suburb of Basel where a new residential and commercial district is taking shape. The grey exterior of the building has concrete bands and neat rows of windows that reference the railway tracks. And facing the street, the façade cuts in to give each department its own entrance – after all, jurors and the accused cannot share the same doorway.

“There was no precedence,” says Kunz of the project, completed in 2014 and now fully operational. “Combining these three functions in one building makes life easier,” says Dr Gerhard Mann, director of security for the canton of Basel, which was on hand to ensure the complex delivered all necessary safety measures. “Transporting prisoners is costly and time-consuming. Not having inmates leave the complex is safer.

“We have everyone here, from thieves to murderers,” adds Mann with a nonchalance that can only be due to his 30 years in the business. Some are here for longer stays but the majority of prisoners in Muttenz are awaiting trial. Hence the importance of the courtroom at the heart of the complex.

“Courtrooms should be imagined like a small theatre,” says Kunz. “There’s the stage for the judge and the accused, then a place for the lawyers and the audience, with the judge towering above everyone. Each case is a production, its own world.” The courtroom at the Criminal Justice Centre has lavish parquet floors and bespoke wooden furniture. Rows of specially designed pendant lights give this most serious of theatres a certain warmth.

It’s a warmth that surprisingly isn’t lacking in the jail cells. On the fourth floor, effort has gone into creating custom-made furniture units combining a single bed and closet in a simple design to discourage vandalism. Solid natural wood gives the cells a human touch: unlike plastic it will age gracefully over time and give inmates a sense of time passing even behind bars.

“To improve the mood we wanted to bring colour to the cells,” says Kunz, who wanted them to feel as homely as possible. “A grey cement floor would have been a shame so we worked together with a colour psychologist to select the best shade for the cells.” The result: lime green.

“The colour is meant to have a positive and calming effect on the prisoners,” he adds. The architects even designed a “cool down” cell in pink. When an inmate gets particularly aggressive they’re placed in here. Even the washrooms have been painted a petrol blue to promote harmony.

There are limitations when designing a prison. Cells are fitted with windows to give inmates a sense of freedom but they cannot see far. Each is fitted with a special foil to restrict prisoners from being able to see more than the sky. “It’s designed to stop inmates from being able to communicate with outsiders on the street. The collision of inmates and the outside world is particularly critical when they’re held in custody pending a case,” says Kunz.

This is a building that affords dignity to inmates and eases the judicial process – as much as a piece of architecture can. It’s hard to tell that this complex is home to a prison. Only after the sun has set and the lamps have been switched on are the bars visible.

Most prisons are designed so that inmates can actually escape. And while the chances of doing so successfully are made minuscule, the possibility is still there. “If the option didn’t exist the prisoners would simply go crazy,” says Thomas Käszner, project manager for architecture firm CF Møller on Denmark’s new high-security Storstrøm Prison.

Giving a glimmer of hope through design in what can be a hopeless situation is one of many unique considerations that the Copenhagen-based firm has had to deal with for this commission on the island of Falster. A home for some of the nation’s toughest criminals, it will see inmates begin moving in from its outdated predecessor this October.

For an architecture firm respected for promoting Scandinavian ideals of openness in its work, dealing with the idea of containment has been trying. “In Danish society, where people pretty much come out of jail after a maximum of 14 or 15 years, you really have a job to do,” says CF Møller partner Mads Mandrup Hansen. Even with those sentenced to “life imprisonment” in Denmark tending to serve an average of 16 years in jail, it has been the idea of designing for hope and rehabilitation that has marked the project. “The aim is to begin rehabilitating prisoners from the moment they step inside,” says Käszner.

While rehabilitation comes from procedures created by Denmark’s prison authorities, touring the jail on a grey Falster day it’s clear that the architect’s creative thinking also plays a key role. At every turn security is balanced with thoughtful design for both inmates and staff. Cells with vertical windows provide soothing views of the land and sky, while the interior walls are carefully curved so that the view for entering guards is maximised to avoid surprise attacks. The perimeter wall also bends in line with the natural landscape (rather than simply boxing inmates in), while every aspect of joinery and sealing in the building is made completely seamless to give no space to stash contraband.

“We worked on all kinds of scales and in many ways you can compare it to normal society,” says Hansen. “We were trying to mirror society and I think that many of the best prisons do. We also took ideas from the old-school factory model of a prison where you had a cell, a factory, a common area and library. It gives prisoners a sense of purpose.”

Storstrøm Prison, in essence, is a village. In fact the surrounding villages, built around community centres, were an inspiration for the prison’s overall layout. Yet despite all this thoughtfulness, it by no means feels like a pleasant place to be. “Ultimately it’s a punishment to be here and not a holiday,” says Hansen. “I would not wish it on my worst enemy to be in a prison with these tough people. But by adding soft architectural elements and collaborating with artists to provide works inside that are counterpoints to this toughness, you create a certain atmosphere that works for this purpose.”

For CF Møller, Storstrøm Prison will remain an anomaly in a portfolio spanning from an eco-sensitive school with an exterior clad in solar panels to the design of urban furniture for light rail. The reason, Hansen says, is that designing a prison goes against the dna of what, above all else, an architect wants to present: an enjoyable environment.

“We really had to rethink our approach and what we did was to take all the great learnings from past projects and add these into a sort of artificial city – a basic urbanised ‘thing’ within walls,” he says. “The best solution was to create something that was as close to a normal situation outside the walls as possible.”

In Japanese cities you’re never far from a police box, or koban. They’re on street corners, near train stations and in the centre of busy commercial districts. They have been a constant since they first appeared in the 1870s. At last count Japan had nearly 6,300.

Staffed by officers known as omawarisan around the clock, kobans are where you go to to report crime, seek shelter, get directions, gripe about a neighbour or leave and claim lost items. They’re pint-sized police stations, with a koban sign and a glass case filled with wanted posters.

You can’t miss them but that’s not because all koban look alike: they’re made of brick, tile, cement or metallic sheeting and come in myriad shapes and sizes. Some are quirky; some have a sign with the police’s yellow Peepo-kun mascot on it. And some have been designed by prominent architects.

Edward Suzuki’s koban in Tokyo’s Shibuya district, built in 1985, has a curved roof that resembles the blade of a hatchet. Kiwako Kamo and Manuel Tardits designed one in Kumamoto city that’s straight out of a Miró painting. They’re striking examples of how art can transform this potent symbol of authority into a beloved landmark. You would never guess that behind the whimsical exterior is a holding cell for suspects and a bedroom where officers can rest after a long shift.

The idea of building a police outpost that would make officers seem more approachable drove the design decisions at Klein Dytham Architecture. The Tokyo firm’s koban, in front of Kumamoto railway station, has a façade with circular cutouts that reveal a colourful roof behind. “The joke is that it’s a play on the black-and-white police car,” says Mark Dytham of the project, which was completed in 2011. They were commissioned through Kumamoto prefecture’s Artpolis public buildings programme, led by architect Toyo Ito.

“We wanted it to be joyful and feel friendly so children or young people wouldn’t be afraid to interact with the officers inside. Now Kumamoto uses photos of the koban on PR materials.”