Urban Update 25 October 2024

Designing with Trees – A free afternoon on-line seminar

There is a pressing need to increase the number of trees in urban areas.  There is value in countering the urban heat island effect, boosting biodiversity, and also as an amenity that can improve well-being: there has been plenty of research along the theme of the biophilia hypothesis, the benefit green environments have in reducing stress, and redressing attention deficits.   There is also the 3:30:300  "rule of thumb" – that there should be 3 trees visible from one’s home, a 30 percent neighbourhood tree canopy cover, and no home more than 300 metres from the nearest park or greenspace

But….tree planting needs to be considered carefully. 

People have different preferences …some people like natural landscapes, others prefer a more urban look, and there are cultural differences (see the research by Bridget Snaith >>>>

  • Some streets traditionally had few or no trees. Medieval market streets in particular were used for livestock and any trees that were not behind a stout fence would be chewed by livestock. However there are plenty of examples of such streets where trees planted on private land near the highway can grow to great size and have a wonderful effect.
  • Some tree planting schemes have been designed without consideration of the pedestrian perspective, streetscapes, distant vistas, the impact on the occupants of buildings, and the enhancement of architecture.  There have been examples of trees being planted directly in front of Grade 1 listed buildings.  It has been said, it is not where you plant trees that matters, its where you don’t. 
  • Trees also plant themselves and will colonise new areas if allowed to do so. An example is in Durham where parts of the cathedral and castle are no longer visible owing to the spread of self-seeded sycamores.

The Trees and Design Action Group are running a free event on Designing with Trees, which will cover best practice - planting the right tree in the right place for spectacular results - Tuesday 29 Oct 29 at 2:00pm   >>>>

 

Built Environment 

Vital green spaces are disappearing in NZ cities—what can central and local government do? >>>>
In Auckland, private green space per person decreased by approximately 20% between 1980 and 2016.

Urban green spaces are essential for residents' well-being and as a climate adaptation strategy. Their quality and availability must be protected and enhanced through council policies, yet current policies vary significantly between councils.

While private green spaces are being lost due to urban intensification, overburdened councils can't be solely responsible for compensating for this. Policies must ensure adequate provision of green infrastructure.

Strategic and creative design can integrate green spaces within medium and high-density developments, including features like green roofs and walls, if supported by appropriate policies.

Funding for maintaining and enhancing green spaces is crucial.
 
More housing in cities is possible without sacrificing green spaces, sustainable development study finds >>>     >
By 2050, the Netherlands will need nearly two million additional homes, which presents challenges related to space and the environmental impact of construction materials.   This research explores the best places and methods for building, focusing on material efficiency and green space integration.
The study is based on two scenarios from the Netherlands Environmental Assessment Agency (PBL), looking at population growth in densely populated ('dense') versus sparsely populated ('sparse') areas. Materials needed for each scenario were calculated and the impact on the natural environment evaluated.

  • Densifying urban areas is generally more efficient in terms of material and land use because urban homes are smaller, and vertical construction is common.
  • Reusing materials during construction enhances efficiency further.
  • In the "densification scenario," green spaces can be increased by up to 3%, leading to more cooling, rainwater absorption, and recreational areas.

Further research will address biodiversity and health impact.
 
What factors encourage city centre visits?
The relationship of the city centre to its surroundings: Correlations between urban spatial structures and inhabitants' frequency of city-centre visits in four Norwegian cities - 
Cities
This study looks at how land-use structures and transport systems affect how often people visit city centres.  The research supports the idea that multiple factors contribute to city-centre visits, and outcomes vary based on local context.

  • People visit city centres more often in cities with concentrated urban structures and easy access to the centre.  Good transport systems are crucial for frequent visits.
  • Perceived attractiveness of a city centre plays a big role in encouraging visits.
  • Nearby Competing retail/service hubs can reduce visits.  The absence of competition encourages more frequent visits.
  • Cities with fragmented, spread-out structures see fewer frequent visits.
  • Living or working near the city centre increases visit frequency, and dense areas counter the pull of competing destinations.
  • Negative perceptions, such as traffic and parking issues, can reduce visit frequency.

 
Conclusions: Urban planning and design should focus on

  • densifying city centres,
  • ensuring mixed retail/services,
  • making access easy by various transport modes.
  • balancing land-use and transport systems to keep city centres attractive and accessible.
  • avoiding changes that reduce city-centre appeal, such as over-prioritizing car space at the expense of walkability.

 
UK: Why are we building homes when so many are standing empty? BBC
“There are just short of 700,000 empty and unfurnished homes in England, according to the most recent government figures, external. Of those, 261,471 are classed as “long-term empty,” meaning no-one has lived there for six months or more.”
Latest housing statistics for England >>>>
 
Better than the Elizabeth Line? Chowdhury Walk wins RIBA's best new affordable housing award >>>>
 

Retail

The pace of change the retail has taken many by surprise, with the last department stores being built and opened in the late 2000s and closed barely 10 years later, with building owners left puzzling as to how to find new uses.   At the same time, car-based out of town retail parks appear to be surviving and some are thriving.
 
The demise of the UK shopping centre >>>>
A thoughtful article from the Guardian on changing retail patterns.   One observation is over the loss of large shops from town centres.  
 
Boston “is dying from the inside out”, retailers warn >>>>
Vacancy rates now run at 25 percent
 
Bid to overhaul Ashford’s ‘unviable’ market as traders could move back to Upper High Street >>>>
This is a challenging case study of town-centre troubles. Around 25 years ago planning permission was given to a car-based retail outlet to be built on former railway sidings around 1500 metres from the town centre.  In the 2000s a town centre scheme went ahead, along with the reversal of a 1980s ring road scheme, and public realm improvements using shared space principles, with advice being given by the late Ben Hamilton-Baillie.  The out-of-town retail outlet has thrived and has been extended, but the town centre has been badly affected by the change in retail patterns, and the closure of a key department store.  The medieval core of the town which includes over 100 listed buildings is now blighted by vacant shops and inns.  The street market has been a casualty and now finds itself in a less well frequented part of the town. 
 

History

Nottingham: how the remains over the town’s medieval bridge over the Trent 'should be celebrated' >>>>
The remaining two arches of what was one of the largest bridges in medieval England now lie forgotten in the middle of a roundabout.
 

Humans, Health, Society

Urbanization, loneliness and mental health model - A cross-sectional network analysis with a representative sample - Scientific Reports 
This study of 3296 residents in Silesia, Poland, examines the interaction between physical and social environmental factors, mental health, and loneliness, comparing rural and urban areas.
The study firstly confirms the mediating role of loneliness between neighbourhood cohesion and mental health.  It finds that, while urban living is not directly related to increased loneliness, urbanicity (the degree to which an area is urban) can be “a bridge between mental health, social cohesion, physical health, and physical environment.”

Other findings include:

  • The physical environment impacts mental health through neighbourhood social connections and loneliness.
  • Strong neighbourhood pride and social interactions improve mental health.
  • Improving neglected buildings (e.g., repairing damage and removing graffiti) can indirectly boost mental and physical health.  “Poor architectural conditions … [are] directly related to a lower sense of belonging to a neighbourhood”
  • Closeness to public green spaces and urban areas improves physical health, which positively affects mental health.
  • Making public green and urban spaces more accessible can enhance health by encouraging frequent use.
  • Mental health is better in cities compared to rural areas and small towns, but urban living indirectly influences health by connecting social cohesion, physical health, and the environment.
  • Loneliness plays a key role between neighbourhood cohesion and mental health; reducing loneliness by improving social connections can lower mental health issues.
  • High anxiety levels should be addressed first, as anxiety strongly influences other mental health factors.

 
The British Preschool Children’s Play Survey: When, Where, and How Adventurously Do British Preschool-Aged Children Play? - Journal of Physical Activity and Health
This is the first national study on preschool children’s play in Britain, examining where and how adventurously children play and how playtime varies by sociodemographic factors.

  • Indoor vs. Outdoor Play: Children spend more time playing indoors than outdoors, with most outdoor play happening in home gardens, playgrounds, or green spaces. This raises concerns about access to outdoor play and its impact on children's health.
  • Adventurous Play: Indoor play centres, playgrounds, and green spaces are the top locations for adventurous play, but indoor centres (such as soft play and trampoline parks) are becoming more popular due to safety, weather, and traffic concerns.
  • Limitations of Indoor Play: Indoor centres, though adventurous, don’t replace outdoor play due to limited time spent there, entrance fees, and lack of connection with nature or the community.
  • Ethnic Disparities: Children from minority ethnic groups spend less time playing overall and outdoors, reflecting a broader trend related to access to green spaces.
  • Gender Differences: Girls play outdoors, especially in green spaces, less than boys, which may have long-term health implications, possibly due to gender-role perceptions.

This is a survey based on the understanding of parents/guardians/carers, rather than direct measurement of the activity of children.  Past research has shown that parents tend to overestimate the physical activity of their children compared with data provided by accelerometers attached to each child.
 
Health impact of urban green spaces: a systematic review of heat-related morbidity and mortality – BMJ Open
This review of studies finds that findings from Japan, the USA, and Australia, demonstrate that green spaces help to reduce heat stress and mortality.  In Hong Kong, however, green spaces didn’t significantly impact heat-related deaths.     “Almost all studies that are published on assessing the effect of green vegetation on heat-related mortality and morbidity are from high-income countries. However, people living in low-middle-income countries face higher heat-related health issues due to poverty, lack of access to air conditioning and inadequate infrastructure for dealing with extreme heat events.”
 
Socially distanced layout of the world's oldest cities helped early civilization evade diseases >>>>
Living at ever increasing densities brings with it an increasing risk of disease transmission.. by aerosol, droplet, water, food and physical contact. This is an interesting study comparing the morphology of different cities in antiquity, and modelling the likely impact on disease transmission.    

At Çatalhöyük, in Anatolia, southern Turkey, a proto-city occupied from 9500 years ago, with a population of around 5000-7000, the density was very high, with access to homes gained through roofs.    Around 8000 years ago the settlement was abandoned with the population dispersing into smaller settlements.  The paper asks whether this may have coincided with the evolution of diseases such as tuberculosis and salmonella.   

Around 6000 years ago a new wave of settlements emerged such as  Nebelivka and Maidanetske in the Ukraine.   At Nebelivka there were hundreds of wooden, two-story houses were regularly spaced in concentric ovals, which were also clustered in pie-shaped neighbourhoods, each with its own large assembly house.   According to the modelling by the researchers, this arrangement helps to reduce disease transmission.  The article goes on to mention other measures such as water supplied by canals at  Uruk  in Iraq, also dating from around 6000 years ago.
 

Politics, Philosophy, Economics, History

English Folklore and Traditions Survey 60 years on  >>>>
It’s a survey about what people understand about their locality.  And while much is made about ancient woodland, or conservation areas, there is comparatively little interest in the everyday culture of humans.  This revived survey should help to address that.
 
How Edinburgh created the world's first fire brigade >>>>
Fire has been and is one of the main factors influencing urban design and architecture.
 

Natural Environment 

Fungi could be given same status as flora and fauna under conservation plan >>>>
 
Humans Have Erased 3 Billion Years of Evolution – and It’s Getting Worse >>>>
 
Invasive species: Warnings over Christmas tree-eating beetle >>>>
The Forestry Commission is banning the planting of new spruce trees in southern and eastern England from 29 October to limit the impact of an invasive beetle.
 

Movement

 When bike lanes are not enough: The role of connected low-stress cycling infrastructure on cycle commuting in urban Aotearoa New Zealand - Cities
This study examined cycle networks in seven major urban areas in Aotearoa New Zealand using the “Level of Traffic Stress Framework”   proposed as a road classification scheme based on how suitable the road environment is for most people. Roads are classified as ‘low stress’ (i.e., suitable for the majority) or ‘high stress’.  

  • The key factor in increasing bike commuting is the percentage of low-stress infrastructure at both city and neighbourhood levels, with city-wide infrastructure having a stronger impact.
  • New low-stress infrastructure boosts cycling, regardless of its specific location within a city.
  • Most low-stress routes in NZ cities lack dedicated bike lanes, with only 20% being actual bike infrastructure; instead, good road conditions make these roads bike-friendly.
  • Poorly connected low-stress segments create isolated “islands” for cycling, a challenge seen in other studies as well.
  • Improving bike networks requires a holistic approach to the entire road environment, not just dedicated bike lanes, highlighting areas where connectivity is lacking.
  • Limitations to the use of the LTS framework include LTS not accounting for traffic volume and road gradient, which can impact cycling choices.
  • Overall, adding low-stress infrastructure, like reduced-speed zones, can improve cycling uptake even without dedicated bike paths.

 
Effects of different mobility concepts in new residential areas - Journal of Urban Mobility
 
Growing cities need new residential areas, but these often lack good transport connections.   Roads are built quickly to connect these areas, but this promotes car dependence, conflicting with sustainability goals.  Uncertainty about public transport success reduces investment willingness.
 
This study examines mobility options for a new Berlin neighbourhood of 2,000 households.  Trips from this area are longer than the city average, limiting biking due to range. Mobility options include shared mobility, bike highways, frequent bus service, suburban trains, and car restrictions.

Simulations reveal that

  • minor transport solutions don’t significantly change car use.
  • Only extensive options, like bike highways combined with suburban trains, reduce car dependence.
  • Shared mobility is helpful occasionally but not for regular travel due to high costs.
  • Public transport is beneficial for long trips, avoiding traffic and parking issues.
  • A suburban train in the final scenario had the most impact on shifting transport modes.
  • Effective change in public transport requires extensive infrastructure like new metro lines.
  • Connecting bike lanes to a city network and expanding high-performance public transport reduces car use by over 40%.

 
Scan reveals inner workings of oldest model steam locomotive >>>>
 

Energy and Climate Change

Life on earth - why we should thank our lucky star, and just the right level of carbon dioxide .  How the changing intensity of starts and planetary carbon dioxide levels may have blocked evolution of life in other planets >>>>

A reminder here that the circumstances in which life has evolved on the earth are very finely balanced.  The light and heat emitted by a star, and the position of orbiting planets and the levels of carbon dioxide in their atmospheres mean that evolution of life may not be possible. 

Polar Ice Crisis 2024: Arctic and Antarctic Near Historic Lows >>>>
 
Global coral bleaching event expands, now the largest on record >>>>
 
Energy cost of growing micro-greens in vertical gardens >>>>
50 percent of energy used goes in artificial lighting, the rest in ventilation heating and irrigation
 
Co-designing the urban energy transition: A residents-based approach - Cities
Increasing electricity demand and renewable energy goals are driving small-scale power production in cities. This study explores how participatory design and renewable technologies, like solar panels, enhance democratic and sustainable urban planning. In workshops in a Swedish suburb, residents and local stakeholders, including municipal and energy company representatives, collaborated to address community energy needs. Findings highlight residents' creative input, the importance of inclusive planning, and the need for multi-stakeholder collaboration to tackle regulatory and shared energy challenges effectively.