Urban Update 29 February 2024

  • Competition and Markets Authority Report on Housebuilding - summarised
  • Air Quality
    • "Safe" air quality levels in US, UK and EU harmful 
    • London high air pollution days shown to impair problem solving by teams - slowed by 5 percent. 
    • Early life exposure to air pollution linked to increased asthma incidence
  • Vision Zero road safety projects found likely to have had zero adverse impact on businesses
  • Safety and naturalness + tree canopy factors in the effectiveness of parks in restoring attention (Attention Restoration theory)
  • Cooling effect of different types of green / blue infrastructure eg 5 centigrade for botanical gardens through to 2.9 centigrade for reservoirs and playgrounds
  • Interactive coastal risk map - shows which areas are at risk of flooding and when
  • Exemplar 20 minute neighbourhood to be built outside Edinburgh


Politics, Philosophy, Economics


Housebuilding market study final report published - Competition and Markets Authority

Warning: some of the coverage in the media has selectively reported the findings, for example by stating that the report blames the planning system for most of the problems.  It doesn’t.  It cites a range of factors, of which the planning system is just one.  The summary below tries to be as true to the source as possible.   While the report looks at the situation in the UK, it will be of interest to any country where the supply of housing land is controlled by a planning system, and/or the housebuilding sector is dominated by a small number of large firms (economists sometimes use the term “concentration”  to describe this).

This report goes through key issues impacting housebuilding across the U.K.:
It finds that a housebuilding shortfall of at least 50,000 homes per annum is caused by:

  • The nature and operation of the Planning System
    • Lack of predictability
    • Length, cost, and complexity of the planning process
    • Insufficient clarity, consistency and strength of LPA targets, objectives, and incentives to meet housing need.
  • The limited amount of housing being built outside the speculative approach (housebuilders buying land in advance of the construction and sale of homes, for profit, and without knowing the final price at which they will sell the homes), with the alternatives being affordable housing, self-build, and build-to-rent.
    • The paper notes that this form of housebuilding is greatly impacted by the business cycle and macroeconomic outlook, i.e. housing demand rather than housing need, and tends “to under-deliver housing relative to the socially desirable level”.
    • The paper also suggests that “instead of building houses as quickly as possible, a range of evidence shows housebuilders tend to build them at a rate that is consistent with the local absorption rates, ie, the rate at which houses can be sold without needing to reduce their prices.”
    • The study notes further that “the profitability of the 11 largest housebuilders has been generally higher than we would expect in a well-functioning market during those periods outside the Global Financial Crisis and its immediate aftermath.”

The housing shortfall is also found to be impacted to a lesser degree by weak competition in the following:

  • Quality of new homes produced and service provided by housebuilders
    • The study acknowledges limitations in how far competition drives quality:
      • Consumers are limited in the attention they give to quality over other factors, such as location, availability, and price.
      • Consumers only have limited information available on quality when making purchase decisions.
    • The study also considers that redress routes are not sufficiently clear and comprehensive to offer effective consumer protection for resolving issues after purchase.
  • Low-levels of innovation
    • The study finds that “levels of innovation in the industry are lower than we might expect in a dynamic, well-functioning market”.
    • It notes that the take-up of modern construction methods has been slow, largely due to high upfront costs, even where these are expected to reduce costs over time, and the need for multiple stakeholders (including local authorities, lenders, and warranty providers) to buy into take-up.
    • The study instead argues that “the key drivers for innovation in energy efficiency have predominantly been government intervention through regulation, stewardship, and funding rather than competition.”
  • Private management of public amenities on housing estates such as roads, sewers and drainage, and public open spaces
    • The paper identifies significant consumer detriment in this regard:
      • Arrangements often come with inadequate protections for consumers and create significant detriment for households over an extended period.
      • “The root cause of detriment for such households is the reduction in levels of adoption, meaning that households end up paying for amenities which are used by the public. This has resulted in a proliferation of private management arrangements in which estate management companies may possess significant market power and face limited competitive constraints to deliver services at a reasonable price or to an acceptable level of quality.”

Nevertheless, the study does “not consider that competition in the land market, or the land banks held by different housebuilders individually or in aggregate either locally or nationally, is significantly distorting competition between housebuilders in delivering houses”, but that these “reflect underlying issues in the operation of the market” such as the planning system. It does suggest further investigation for this sector, however.
Initial recommendations include:

  • Public amenities (roads, sewers and drainage, and public open spaces)
    • Address the increasing prevalence of private estate management arrangements and the negative effects this can have and consider options to support the adoption of public amenities on estates currently under private management arrangements.
  • Housing quality
    • Improve quality and redress routes for consumers.
  • Planning system
    • Acknowledging the other political objectives impacting regulations etc. the study limits itself to proposals such as
      • More objective and effective use of targets to ensure housing need is met.
      • Streamlining the planning system to significantly increase the ability of housebuilders to begin work on new projects sooner.

However, the paper emphasises that “even if policymakers make the changes we have proposed, the market may still not deliver the quantity of homes, supporting a level of affordability, that policymakers find acceptable”. Indeed, the paper acknowledges that “looking at the history of this market, it is notable that housebuilding has only reached the levels that are currently being targeted in periods where significant supply was provided via local authority building”.

The paper acknowledges that:

  • market outcomes are heavily influenced by external factors, such as interest rates, mortgage availability, the rate of new household formation, demographic change and the level of household incomes;
  • market cyclicality and the speculative housebuilding model means that private housebuilders do not collectively have the necessary incentives to build houses at the rate required to meet policymakers’ objectives.

The paper therefore further recommends:

  • encouraging non-speculative housebuilding models including self- or custom-build homes.
  • considering reforming the land market or building on existing measures to further support increasing build-out rates. For instance, governments could consider a more active role for the public sector in the purchase and assembly of land for development.
  • increasing significantly their delivery of publicly-funded housing by local authorities or housing associations.


Competition probe launched into 8 major house builders by the Competition and Markets Authority >>>>


Urban Theory by and for Whom? Engaged Research, Authorship and Transformation Beyond the Academy - Dialogues in Urban Research

This paper is a personal response to Loretta Lees’ plenary at the Association of American Geographers Annual Meeting in 2023, where she emphasised the importance of engaged research and dialogue, reflecting on her experience as a working class academic as well as on her own discomfort as an ‘inside-outsider’ in urban studies as a result of her perception of its privileged position and tendency to marginalise other forms of knowledge.

The paper explores how to bring critical urban studies closer to the communities and concerns that animate it, from “extending opportunities for dialogue and engagement beyond academia” to “expanding urban scholarship to include non-academic authorship”.

Built Environment 


An ‘exemplar’ 20-minute neighbourhood to be built outside Edinburgh >>>>


Landmark buildings that have been reinvented >>>>

Including Battersea Power Station, flour mills, grain silos etc

How the Barbican became one of London’s most popular places >>>>

A historical perspective.

A data-driven approach to analyse the co-evolution of urban systems through a resilience lens: A Helsinki case study - Environment and Planning B: Urban Analytics and City Science

This study uses a series of snapshots of spatial data focusing on how the road infrastructure, socioeconomic system and buildings of Helsinki co-evolved and adapted to crises between 1991-2016.
The study’s findings included the long-term effects of a recession in the 1990s in terms of socioeconomic disparities, and it noted that buildings and road infrastructure change relatively slowly, while socioeconomic characteristics exhibit greater volatility.

The study further suggests that “new development of buildings and road infrastructure connectivity follows plans driven by factors such as the availability of space, previous constructions or planning interests” rather than socioeconomic changes.

The study emphasises from its findings that urban planning should consider more flexible timescales and adopt a more holistic approach rather than focusing on a single aspect of urban development, studying various systems collectively.


Humans, Health, Society


‘Almost 10m UK households living in ‘cold, damp, poorly insulated homes’ >>>>


The 'chronoworking' productivity hack that may help some workers excel >>>>


Urban Park qualities driving visitors mental well-being and wildlife conservation in a Neotropical megacity - Scientific Reports

This study first divides the characteristics of greenspaces into naturalness (how natural an area seems), soundscape (how pleasant the surrounding sounds are), management (maintenance of facilities and vegetation), and safety, and then surveys how far these contribute to an individual’s perceived restoration (Attention Restoration Theory).
The paper emphasises that the quality of the space impacts the user’s experience:

  • Safety was the strongest factor, particularly for women, a basic condition for the others to be effective.  This perception was impacted by how well-maintained an area was explained by the ‘Broken Windows’ theory: “when signs of disorder are left unrepaired the feeling of carelessness raises fearfulness in residents, which may not be associated with an actual increase in crime rates”.
  • Naturalness had the second strongest effect, when users had an “impression of being in a place similar to a natural habitat with several animal and plant species”, emphasising the importance of biodiversity.
  • For vegetation the beneficial effect of higher levels of tree canopy was noted.
  • The study also found that accessible and natural water features had a positive effect.


Teens benefit from "forest bathing" – even in cities >>>>

This University of Waterloo study is the first to measure the impact of urban environments on adolescent mental health through real-time surveys.

  • Natural spaces like parks, trails, and waterways significantly reduce anxiety in teens compared to busy downtown areas.
  • Even brief exposure to nature (2-3 minutes) shows positive effects.
  • Urban design elements like nature motifs on buildings, landscaping, and access to parks can improve youth well-being.
  • The study emphasizes the importance of considering youth perspectives in urban planning and design.

Future research will explore the long-term effects of urban environments on mental and physical health, including the impact of high-rise living on children.

This research highlights the positive effects of nature on teenage mental health and advocates for incorporating more natural elements into urban design to enhance young people's well-being.

Exposure to more ready-to-eat food outlets linked to a higher risk of heart failure, in a new study in the Circulation: Heart Failure journal


Safe’ air-quality levels in US, UK and EU still harmful for health, study says >>>>


Air Pollution - higher levels of air pollution impair team performance according to University of Cambridge Study using London data

A new study finds that high levels of air pollution decrease team's abilities to solve complex tasks, such as those that are crucial for innovation in fields such as clean energy and vaccines.

  • The study used data from 15,000 escape room games in London, analyzing teams completing collaborative puzzles within a time limit.
  • Results showed a 5% increase in completion time for teams participating on high-pollution days compared to low-pollution days.
  • This effect is more pronounced for corporate teams than younger groups and occurs at levels below WHO air quality guidelines.
  • The study suggests negative impacts on economic development in highly polluted emerging economies where team-based innovation is crucial.
  • Authors recommend reducing air pollution as a potential way to boost innovation and economic growth in these regions.

The research will provide a boost to cities introducing Ultra-low emission zones, and could be critical to improving the competitiveness of the city economy. 

Early life exposure to air pollution linked to increased asthma incidence in early and middle childhood >>>>


Why do people not prepare for disasters? A national survey from China - npj Natural Hazards

This survey-based study found that the main reasons for a lack of preparedness for disasters were

  • lack of awareness,
  • limited access to preparedness products or services, and
  • low perceived response efficacy.  (which probably means a feeling of helplessness)

“The study therefore emphasises the importance of community outreach and public education from disaster and emergency management professionals and providing channels for the public to become aware of and access either products or services or skills about disaster risk reduction.”




Case-control study of Vision Zero road safety projects in Seattle concludes that they are unlikely to have negative impacts on local business sales >>>>

Seattle aspires to be both walkable and bike-friendly, and its Vision Zero programme aims to eliminate traffic deaths and injuries (Vision Zero) through infrastructure projects.  However businesses sometimes oppose these projects fearing revenue loss due to parking reduction and traffic disruption. A University of Washington study has found no negative impact on businesses near such projects for three years after construction.

Researchers analysed seven different safety projects and compared businesses near them to similar ones unaffected. Neither case or control businesses saw any significant sales change, suggesting minimal economic harm from the projects.  The study has limitations, like not considering specific business types or the impact of unaffected parking options.

Overall, the study suggests that Seattle's Vision Zero projects might not negatively impact local businesses, potentially even benefiting them in some cases. This can help encourage collaboration between city officials and businesses in creating safer and more walkable communities.


Natural Environment 

Growing certain , such as maize, can cause soil erosion and runoff on high-risk soils leading to pollution and flooding - Environment Agency
Sandy soils are vulnerable to soil erosion.
Clay soils are vulnerable to compaction, loss of permeability and consequent increases in run off.
Growth of maize involves creating a bare seed-bed at times of year which may also increase run-off.
Past research suggests that healthy, uncompacted soils play a crucial role in flood risk mitigation.


Energy, Climate Change


Wetlands, parks and even botanical gardens among the best ways to cool cities during heatwaves  >>>>

These are the findings of a systematic review of the efficacy of Green Blue Infrastructure (GBGI) for mitigating urban heat by researchers at the University of Surrey. The findings show that GBGI offers a promising strategy for urban cooling, with various co-benefits such as stormwater management and carbon sequestration. However, unintended consequences like increased maintenance costs and potential land-use conflicts also exist. The effectiveness of GBGI varies depending on factors like location, type of environment, and climatic conditions. Further research is needed to address knowledge gaps in areas like water availability, optimal design strategies, and long-term performance.

Results obtained by measurement, modelling and mixed methods:




Botanical gardens


-2.2°C to -10°C



-1.2°C to -12°C

Rain gardens


-1.3°C to -7°C

Green walls


-0.1°C to -18°C

Street trees


-0.5°C to -12°C

City farms


-3.0°C to -3.9°C



-0.8°C to -10°C



-1.8°C to -5°C



-2.8°C to -3°C

For convenience we are repeating the following research summary from last week's Urban Update


When it comes to cooling cities, polycentric development with lots of dispersed green spaces works best >>>>

This Cornell University study investigated how urban design affects heat mitigation in cities. Researchers compared two scenarios:
1. Monocentric: A single, dominant city centre with sprawl of impervious surfaces (e.g., concrete) absorbing heat.
2. Polycentric: Multiple, smaller city centres with dispersed green spaces throughout the urban area.

The findings showed that polycentric development with dispersed green spaces cools cities down more effectively than monocentric development due to several factors:

  • Reduced heat absorption: Smaller, dispersed green spaces break up large swathes of heat-absorbing surfaces, offering more cooling throughout the city.
  • Improved air circulation: Multiple city centres allow for better air flow, preventing heat from getting trapped.

This effect is particularly beneficial for larger metropolitan areas, highlighting the importance of coordinated regional planning for heat mitigation strategies. While denser urban development has other sustainability benefits, it's crucial to integrate green spaces and avoid sprawling heat traps.
The study suggests that regional-level planning can:

  • Promote polycentric development: Create multiple, smaller city centres instead of a single, dominant one.
  • Coordinate green space patterns: Ensure green spaces are dispersed throughout the region, not just concentrated in one area.
  • Increase density in suburban nodes: Make existing suburban areas more compact and walkable, reducing reliance on cars and heat-generating sprawl.

These strategies, beyond mitigating the urban heat island effect, offer additional benefits like limiting sprawl, promoting public transit use, and increasing affordable housing.

Japanese cherry blossom set to start 10 days earlier this year due to global warming >>>>


Megacities are causal pacemakers of extreme heatwaves - npj Urban Sustainablity

Of interest if you are a researcher working in this area. 

Solving Singapore's Urban Heat Island Effect >>>>

Discusses creating a "digital twin" of Singapore to model the effect.  Digital Urban Climate Twin (DUCT).

Interactive Coastal Flood Risk Map >>>>

An interactive map showing areas threatened by sea level rise and coastal flooding. Combining the most advanced global model of coastal elevations with the latest projections for future flood levels.