Nicholas Boys Smith is the chairman of Create Streets, a group focused on making urban areas more livable and human-centric. He is credited with popularizing the term "gentle density." This concept describes a type of place that balances the advantages of personal space with the benefits of proximity to neighbors, shops, and work. The goal is to achieve enough density to support local amenities like a shop, pub, or public transport.

What we mean by gentle density is the type of place which has the advantages of personal space, of control of your own environment, but also the advantages of propinquity, of proximity to neighbors, shops, places to work, enough density to support a local shop, a pub or a bar or a bus or a tram or a train.

Nicholas contrasts this ideal with two extremes. One is thoughtless, low-density sprawl. The other is super density. For example, the Nine Elms development in London features tower blocks arranged to maximize river views, but this design has created windy and unpleasant public spaces. The wind effect from tall buildings is a well-understood phenomenon. Nicholas notes that near the Economist's Tower in London, the microclimate is noticeably colder and windier, which is usually not pleasant in a temperate climate. In contrast, Pimlico, a mid-19th-century London neighborhood with terraced houses and mansion blocks, serves as a good example of gentle density that successfully optimizes these trade-offs.

In the UK, about 69% of people say they prefer a detached house. This preference is understandable, as these homes offer more space, a garden, and control over one's immediate environment. However, there are significant trade-offs. Well-planned, gentle density provides a better balance. It combines most of the advantages of lower density with the benefits of city living. Someone in a terraced house might have a smaller home and garden, but they gain proximity to schools, local shops, and public transport, which is made affordable by the higher density.

The case for gentle density is between the advantages of private space and the advantages of propinquity. That's the trick of gentle density. It's not perfect. Nothing in this world is perfect. But you're more likely to optimise for more people much of the time.

A prime example of bad sprawl is Ebbs Fleet, a major development near a train line. Just a few hundred yards from the station, there are two-story detached houses with wide roads, representing a very inefficient use of land. That is precisely where density is most valuable. In contrast, Pimlico in London is a beautiful example of gentle density. The area was built in the mid-19th century by developer Thomas Cubitt, who used a pattern book of simple Italianate house types. He created variety within a consistent pattern, achieving high but not overwhelming density. The entire development was constructed under strict regulation from the landowner and followed the London Metropolitan Building Acts, contributing to its lasting appeal.

A pattern book, also known as a design code, is a set of pre-designed elements for a town, village, or city. These can include specifications for street layouts, material types, or window designs. The focus is typically on the public-facing aspects of a building or the public realm.

A key philosophical distinction exists between the public and private spheres. What someone does inside their own home is their business, as long as they do not break the law or harm anyone. However, when building in a street, one is creating something public by definition, not private. Because of this, the state has historically been involved in setting standards for the public realm, often through regulations that function like a pattern book.

In London, historical building regulations like the London Metropolitan Building Acts essentially created a de facto pattern book. These acts stipulated rules for materials, distances, and building sizes. Today, many people find design codes alien, as we are more accustomed to rules about safety rather than aesthetics. However, historically, these design rules were the norm.

The reason why anyone who's vaguely historically interested can walk around London and normally date a building with a reasonable chance of getting it roughly right is largely because they're following the regulations and the codes that were required at the time.

Nicholas explains that this historical model can be applied today. He suggests using codes and pattern books to make it easy to build what he calls the "good, ordinary." If a builder follows the pattern book, they could be pre-approved, removing risk and simplifying the process of getting financing. This approach doesn't ban unique or ambitious designs. Instead, it creates two paths.

If you want to do something bigger and weirder or uglier or more beautiful, that's fine. The planning system's over there. Take your chances. You may get a no, but we're not going to ban you. But you just need to be aware you're going to be taking a greater level of risk.

The goal is not to increase risk for innovative projects, but rather to de-risk the construction of buildings that fit a reasonable standard most people would find acceptable.

In architecture, "variety in a pattern" is a desirable feature. It means that as you walk down a street, there is a coherent structure and repetition, like the rhyme scheme in a poem. However, within that pattern, there are also small differences and pleasant surprises. Nicholas explains this concept, noting that emerging neuroscience suggests people find this blend of coherence and variety more enjoyable.

You've got a different head to a column there, or you've got a different fan light there, or suddenly you've got a slightly different window. You get variety, you get little surprises, but they're within that overall framework.

While some people, like Sam, appreciate pure repetition seen in places like Paris's Rue de Rivoli, Nicholas argues these examples work because they have other enriching qualities. The Rue de Rivoli is grand, textured, and highly ornamented, while the Royal Crescent at Bath is beautifully curved. This kind of repetition is very different from unadorned, monotonous designs.

The new proposed Marks and Sparks in Oxford Street is a spreadsheet without detail or ornaments of the same window repeated time after time without any texture or pattern to it. Most people, based on the stats, dislike that type of repetition.

However, simply adding variation is not always better. Poorly executed variation can be worse than simple repetition. Sam gives the example of the Moorfields Eye Hospital, which he describes as visually jarring and incoherent.

It's hanging triangular orange shards going down the side and then there's a completely randomly shaped box that comes out the middle.

The key is that the variety must exist within a coherent pattern, not just be a collection of random elements. Nicholas suggests that traditional architectural styles, whether classical, gothic, or Chinese, often possess this inherent coherence because they grew organically from practical ways of building.

A key factor in why people oppose new building is the perception that new buildings are ugly. This is both a genuine concern and sometimes an excuse that points to a more profound issue: a deep lack of trust. Polling data reveals the extent of this mistrust. For instance, a YouGov poll found that a shockingly low percentage of the public believes new development will improve their area.

2% of the British public. 2%, it's not a typo. Believe that new development will make an existing place better. That's not a great statistic if you're a developer or a landowner.

This mistrust forms a vicious circle. People don't trust developers or local councils. They worry about the loss of green space, increased traffic, and strain on infrastructure like schools and doctors' offices. This leads them to assume the worst about any new project, reinforcing their opposition. It's a spiral of not believing the people in charge, thinking they will make the place uglier, and not knowing what the consequences will be.

However, this cycle can be broken by changing the approach. Nicholas shares an example from Litchfield, a historic market town in England. A centrally located site sat undeveloped for years due to a standoff. The public wanted suburban-style detached homes, while planners and developers argued for high-density buildings. To resolve this, Nicholas's organization flipped the process around. Instead of starting with the contentious site, they asked residents what their favorite parts of Litchfield were. Unsurprisingly, people in Litchfield love the character of their own town, which has a gentle density and variety.

Based on this feedback, they created a building code for the new site that was essentially a code for 'more of Litchfield'. It called for three-to-five-storey terraced houses and mansion blocks that fit the existing urban fabric, with slightly reduced parking. This approach successfully unblocked the planning process without political backlash, demonstrating that focusing on what a place looks and feels like is an essential part of gaining local support for new development.

A mansion block is a 19th-century term for a medium-rise, well-designed block of flats, often associated with Edwardian red brick architecture. However, the discussion extends beyond individual building styles to the broader concept of urban form. It's not just about the architecture itself, but how buildings interact with the street at a human level. Modern financial districts, for example, may feature impressive glass towers that look good from a distance, but at street level, they often present a blank, anonymous wall of glass.

This is where the idea of street animation becomes crucial. The concept was famously championed by the American journalist Jane Jacobs in the 1960s. She wrote about the importance of having 'eyes on the street' and activity at ground level. Nicholas notes that she faced vicious criticism from professional architects and planners for her insights.

She was condemned as the rantings of a sort of coffee stained woman. It's an appalling level of casual abuse that she received from the professions for pointing out something that was true. So she was right and they were wrong.

The form, or morphology, of streets and towns matters for both safety and social connection. A significant mistake in post-war planning was abandoning clear 'backs and fronts' for buildings. A traditional block with houses facing the street and back gardens facing inwards is inherently safer. UK and Australian data show this design correlates with lower crime because it's physically harder to access the vulnerable rear of a property. There's also a psychological effect. When public-facing elements like front doors, shop fronts, or small front gardens all face the street, it concentrates activity. This makes the area feel busier and more sociable, which also contributes to safety.

Specific design features play a key role. Small front gardens are correlated with a higher likelihood of speaking to neighbors. Bay windows signal that people are looking out onto the street, which can deter antisocial behavior. Conversely, blank walls create an environment where people feel unobserved. Nicholas provides a modern example of a poorly designed building with a blank wall and an easily accessible elevated corridor, making the area unpleasant and unsafe.

Finally, a highly connected street pattern, like a traditional grid, allows for many routes from one point to another. This facilitates movement and increases the chance of random, positive encounters at places like street corners, fostering a sense of community without forcing everyone down the same path.

Historically, London's street network grew without central planning, unlike cities such as Madrid or New York. Before the 1920s, landowners expanding the city had to follow certain rules. One key rule limited the length of cul-de-sacs, which naturally encouraged an interconnected street grid.

Today, cul-de-sacs are common and represent a logical reaction to the rise of cars. Nicholas explains they are often seen as desirable because they offer a quieter and safer environment, especially for families with children. This desirability is reflected in property values, with houses on cul-de-sacs often being worth more than those on through streets.

Cul de sacs are a very sensible and rational response to motor cars. And houses on cul de sacs are worth more than the house just off the cul de sac because they're quieter, they're safer.

However, a problem arises when an entire area is designed as a series of cul-de-sacs branching off large feeder roads. This design is an inefficient use of land and makes it difficult to travel between two nearby points without a car. Journeys that should be short walks become long drives.

A better approach combines the benefits of cul-de-sacs with the need for connectivity. This concept is known as "filtered permeability." It involves designing neighborhoods with no through routes for cars but maintaining direct paths for pedestrians and cyclists. Nicholas provides a personal example of living on an estate in Blackheath planned this way in the 1970s, calling it a good trade-off. This approach is being retrofitted in modern cities through initiatives like Barcelona's superblocks and low-traffic neighborhoods in the UK, which block through-traffic for cars while keeping access open for people on foot or bike.

Housing needs vary significantly at different stages of life. Sam recalls living in a tower block when he was younger and single. It was cheap and central, and he didn't mind the lack of community. Now with a family, he lives in a terrace house, a form of "gentle density." He anticipates his family might want more space later, perhaps in a semi-detached house, and in retirement, he might prefer a small cottage.

This illustrates that different housing forms suit different life stages. The issue isn't whether one type is good or bad, but whether some types are undersupplied. Nicholas suggests that gentle density is versatile and can accommodate a larger portion of a person's life compared to the extremes of high-rise towers or suburban sprawl.

Nicholas clarifies that while his organization, Create Streets, is often seen as anti-tower, the reality is more nuanced. Towers can work well for certain people in specific places, such as young or older individuals in city centers, particularly if they are wealthy and have another home elsewhere. However, they come with significant downsides. They are expensive to run and difficult to retrofit as building regulations change. Data, though somewhat dated, consistently links them to poorer well-being outcomes, especially for children and less affluent residents. Towers also tend to inhibit neighborly interaction compared to street-level gentle density neighborhoods.

Housing needs for older people are also changing. As people live longer, often with mobility issues, a secluded house in the country can become isolating. A rational trend is emerging where retirement and sheltered living facilities are being built in historic town centers, like Salisbury. This allows residents to live within walking distance of amenities, which is a sensible adaptation to their needs.

Sam notes that this life-cycle perspective could resolve conflicts between groups like YIMBYs, who advocate for building more housing, and pronatalists, who want more family-friendly homes. The debate can feel artificial when the real goal should be creating an urban mix that serves people throughout their entire lives.

Nicholas agrees, emphasizing the importance of building flexibility into housing. He points out that his and Sam's terrace houses were once converted into flats and then back again. Buildings that can easily adapt their use—from a shop to a house to an office—are valuable because future needs are unpredictable. He suggests that new developments could pre-approve designs that allow for future expansion, such as adding stories to a house. This would allow neighborhoods to evolve organically, a flexibility that has largely been lost in the current UK planning system.

The evolution of cities like New York, from the 'gentle density' of the 19th century to today's 'giga density,' raises questions about development. Nicholas Boys Smith argues that while much of Manhattan is still medium-rise brownstones, major city centers in old, established cities probably should become very high density. He points to London's Strand as a successful example, which transformed from riverside cottages into a bustling area of grand theaters, offices, and mansions. However, he makes an exception for a city like Paris, which he feels should be preserved as is.

The conversation shifts to why historic preservation has become so important. The desire to protect older buildings, like Manhattan's brownstones, isn't always about their historical significance. Instead, it stems from a collective 'collapse of confidence' in the quality of modern architecture. In the 18th and 19th centuries, there was no heritage movement because people generally believed that new buildings would be an improvement. For instance, when London's Regent Street was rebuilt in the 1920s, there was little protest because the new, grander buildings were seen as progress. Those same buildings are now protected historical structures.

This sentiment shifted dramatically by the 1960s and 70s. When plans were proposed to demolish large parts of London, including Covent Garden, for a motorway, the public backlash was immense. This popular resistance marked a turning point, making historic preservation a major political issue. As journalist Simon Jenkins described the public meetings at the time:

Public officials were lucky to get out alive.

This deep-seated distrust in modern development is why many people would rather keep a nice, old building than risk it being replaced by something worse.

Collective land ownership can lead to better urban spaces. When a single entity owns an entire area, not just individual streets or properties, there is an incentive to preserve or create features that enhance the value of the whole neighborhood. A unique street, for example, might not be very valuable in isolation, but it can become an attraction for residents and tourists, boosting the value of everything around it.

A modern example is a new street created by the Cadogan Estate near Sloane Square in London. They repurposed what was previously just the back of buildings, adding small shops and houses. The resulting street is lovely, very tight, and always busy. This development adds value to the surrounding properties and increases rental income for the estate. This demonstrates that while the concept of collective land ownership can sometimes feel uncomfortable, when managed wisely, it can be a sound decision both commercially and in terms of good stewardship.

Nicholas Boys Smith explains the concept of "traffic modernism." It originated mid-century with architects like Le Corbusier, who believed the motor car required a complete reimagining of cities. This vision proposed replacing walkable neighborhoods with large, zoned tower blocks connected by motorways and freeways, surrounded by parkland. Le Corbusier, funded by a French motor company, even proposed a plan called the Plan Voisin that would have demolished much of Paris and replaced it with this vision. A similar, though less radical, plan for London involved concentric motorways that would have caused destruction dwarfing the Blitz.

This urban planning philosophy was linked to a shift in architectural values. Nicholas references the classical writer Vitruvius, who said buildings should be beautiful, useful, and strong. In contrast, modernism evolved to deny the importance of beauty, focusing on a purely utilitarian and functionalist approach. The exterior of a building was seen merely as an expression of its internal function. Nicholas describes this as a selfish, uncommunal, and antisocial way of thinking about buildings.

So that's what I mean by traffic modernism, in its extreme case, the consequences normally are a little bit less extreme than that. But it's fast roads, ugly buildings and no sense of place or home in the world.

While the most extreme versions of these plans were never fully realized, their consequences are visible today. Nicholas notes that 11 of the 12 poorest areas in England have a fast road running through or alongside them. He contrasts this with 19th-century urban projects like the creation of Regent Street in London. While those projects also involved demolition, they created new streets that remained part of the urban fabric. Modern motorways, however, create a "scar" and a "shatter zone," de-stitching the city and lowering property values in their immediate vicinity. The fundamental difference lies in the width, speed, and overall concept of the road being built.

Infrastructure like railways can act as urban scars, dividing neighborhoods. Nicholas Boys Smith uses the example of Primrose Hill in London, which is walled off from Camden by eight railway lines. However, he argues that the negative impact of a modern fast road on a neighborhood is far greater than that of a 19th-century street. The key difference is the gradient of impact. While both can be disruptive, trains are not continuous like a motorway.

For cities, the goal should be to move away from car dependency and toward more efficient transport like bikes, trains, and trams. This is crucial for maximizing the agglomeration effects of cities, where productivity increases with density. A street dedicated to walking, trams, or cycling can move about 20 times as many people as a street for cars. Nicholas clarifies his nuanced view on vehicles.

Cars are great liberators in the countryside. They bring freedom and they can be lovely places to sit in and they can look cool. But in a town they're just not a very good way of optimizing movement for most of us most of the time.

A counterpoint is raised: why is the San Francisco Bay Area, the world's most productive region, so heavily reliant on cars, with 80 to 90% car and taxi usage? Nicholas suggests this is partly due to America's luxury of having far more space than Europe. Replicating such a car-dependent sprawl in a constrained area like the southeast of England would be politically unimaginable.

The UK is millions of homes short, with an economy that is very dependent on the Southeast. Nicholas explains that while the government has set a target of 1.5 million new homes and is focusing on new towns and infrastructure reform, these are slow processes. He is concerned about the slow progress and a watering down of initial proposals. The focus needs to shift from being just house builders to being town builders.

Nicholas sees enormous potential in existing legislation that is currently underutilized. The key is to predetermine what kind of development local people will accept by using design codes and pattern books. This approach allows for the intensification of existing streets and underused sites, a concept he refers to as "Brownfield possible". It's not a free-for-all, but a guided way to build more within existing communities.

A specific example is making it easier to add one or two stories to existing houses. While adding bedrooms doesn't count towards the government's official new homes target, it helps the housing crisis by creating more fluidity in the system. However, Nicholas worries that recent policy changes loosening design quality requirements might backfire. Looser standards could lead to local councils being less likely to approve projects or result in political blowback.

He shares a successful case study from a prosperous part of central London where a pre-approved order for adding a mansard roof to 12 houses was passed. The approval was likely helped because the order also required restoring a historic architectural detail. The success of this small project revealed significant underlying interest from homeowners.

In the just over a year since that mechanism was made, five out of the 12 houses have submitted a planning application or even physically started building. So the latent demand is being revealed.

This principle of pre-approval can be scaled up. In one town, his team gained strong local support for 950 new homes within the existing town fabric, even after a proposal to build on the Green Belt had been rejected. They overcame opposition by showing residents that the proposed three and four-story buildings were similar to beloved existing buildings in the historic town center.

The guy came up to me, ready to have a fight, ready to complain about the four story and the three story buildings that we were essentially suggesting pre approving. We're in the high street of the historic town. I turned around and said, 'Well, look, this is four storeys.' ...And that was basically the end of the fight.

The overall vision is to use pre-approved codes to allow for the construction of everything from house extensions to terraced houses and mansion blocks, potentially creating millions of new homes that fit within existing communities.

Any street built before the onset of modern traffic is probably lovely. This is because it likely uses local materials and complements the streets around it. A great example is Gold Hill in Shaftesbury, England. It features a row of cottages curving down a slope with the English countryside in the background. While not every street can be like this, its appeal is undeniable.

Another excellent example comes from Venice. The city's "fondamenta" are streets with a canal on one side and a row of houses on the other. Beyond the famous grand palaces, the back streets of Venice are incredibly simple and beautiful in their ordinariness. Part of their charm is the presence of water, which people love looking out on. The value of a water view is quantifiable.

Add a view of water to the same street... you will push up land value between 15 and about 85%. Wide range, but it'll always go up.

A renaissance is happening in urban planning. Across the world, more people are creating new places that respond thoughtfully to traditional patterns while using modern technology. Nicholas explains that there are many new neighborhoods to look to for inspiration.

In America, the town of Seaside, featured in the film The Truman Show, has gorgeous, simple, and walkable wooden streets. In France, a place called Clamar on the outskirts of Paris left Nicholas "literally speechless." It is well-connected to the city center by public transport. The buildings are slightly higher density than traditional Paris, at six to nine stories, but they feature numerous balconies overlooking a newly created lake. This design maintains a Parisian feel by using local Lutetian limestone and recognizable metal mouldings. People tend to appreciate things that feel like they belong to a specific place.

In the UK, projects like Poundbury and Nansleddon, associated with King Charles, have created marvellous streets. They cleverly use street trees, bringing them out into the carriageway to gently slow traffic down without feeling annoying to drivers.