The ladder of place quality
In this blogpost, Prof Matthew Carmona (The Bartlett School of Planning, UCL) summarises the “ladder of place quality” research he presented at the CaCHE ‘Delivering well-designed homes and neighbourhoods’ panel discussion on 9 December.
The urban places that most of us inhabit are made up of buildings, streets, spaces and landscape, various land uses and a community of users. As the previous Design Matters column suggested, the quality of place has profound impacts on the lives of people, as regards their health, social well-being, economic circumstances and the environment within which they live. The research underpinning those assertions went on to uncover the truth about the qualities of the built environment that are good for us, and those which are not, and these are presented in the Place Alliance report: Place Value & the Ladder of Place Quality.
As the title suggests, it is possible to envisage different qualities of place as sitting on a ladder. The ladder climbs from those place qualities that should be avoided at all costs when designing new development (because of their very likely negative health, social, economic and environmental impacts); to those about which the evidence is still inconclusive (and where we should be careful not to be too prescriptive in policy and guidance). Next come place qualities that are strongly associated with positive outcomes of all types (and which should be the aspiration of built environment policy and development-related decision-making). Finally we have a limited number of qualities that are fundamental and which should be required in new development as a means to maximise place value through good design.
The ladder of place quality
So what is the evidence for this?
Underpinning the ladder is extensive, robust and powerful evidence from 271 studies that was discussed in the previous column and which was recently brought together in a new wiki: www.place-value-wiki.net. The evidence confirmed that value of different types flows from the qualities of place, and that there is a virtuous loop in which quality dictates value and value defines quality.
Climbing the ladder
As well as revealing much about the different dimensions of place value, the collective evidence also revealed a good deal about the sorts of places that deliver that value; and more specifically about the qualities of the built environment which do that.
Looking across the 271 studies, many were focussed on particular narrow types of value and outcomes. Collectively, however, the results of the studies can be aggregated in order to determine which associations between dimensions of place value and the different qualities of place are stronger, weaker, negative, or simply still uncertain given the available evidence. So let’s climb the ladder.
Step one: avoid
The evidence reveals a VERY strong negative association between some qualities of the built environment and place derived value of all types. Here the strength of the evidence is extremely strong suggesting that these are qualities to be ‘avoided’ at all costs when shaping the built environment. Eight of these negative qualities were identified:
- Car dependent and extensive forms of suburbanisation
- Relentlessly hard urban space (absence of local green space)
- Too much very local permeability (connectivity) in the pedestrian path network (e.g. unsurveilled back alleys and routes)
- The presence of rear parking courts and other poorly overlooked or segregated areas
- Poor maintenance / dilapidation (including of green spaces)
- A sense of overcrowding in residential buildings and estates
- Presence, in close proximity to homes of too many unhealthy food options
Presence of roads with higher traffic loads and speeds, wider carriage-way widths, that are elevated, or which otherwise cause severance in the local built environment.
Avoid rear parking courts
These are largely tangible and measurable qualities and are therefore capable of direct control (in a preventative manner) through formal tools of design governance such as through planning policy, zoning, street adoption powers, or the use of design codes.
Step two: beware
For some qualities of place the research evidence was conflicting or simply not yet definitive enough to come to a firm view about the impact. There are eight issues in this category:
- Particular architectural styles (the evidence does not clearly show the superiority of any one architectural style over others)
- Higher versus lower densities of development (there is conflicting evidence linking both higher- and lower-density living to health outcomes, sociability and perceptions of crime and safety)
- Extreme densities (there is conflicting evidence relating extreme densities to carbon reduction, social welfare, and ecological richness)
- High-rise living the evidence is unclear regarding the social impact of living in high-rise buildings, although it does seem unsuitable for families with children)
- Street length and pedestrian connectivity (the health and crime evidence diverges on the relative benefits and drawbacks of longer versus shorter streets and on how connected street networks need to be)
- Cul-de-sacs (there is conflicting evidence on the impact of using cul-de-sacs on crime and safety, property value, sociability and children’s play)
- Separating vehicle and pedestrian routes through urban areas (the evidence is weak and conflicting regarding pedestrian safety outcomes)
- Use of shared spaces (there is conflicting evidence relating use of shared spaces – spaces shared by vehicles and pedestrians – to levels of both actual and perceived safety)
- Proximity of retail to residential properties (there are divergences within the economic evidence base on the relative size and impact of negative externalities related to living in extreme proximity to retail).
Beware shared spaces
On all these qualities, more research is required, and care should be taken when seeking, without very good reason, to be prescriptive on such issues in policy or guidance.
Step three: aspire
There is a strong positive association between place derived value of all types and fifteen further qualities of place. Whilst the evidence on each of these is powerful, it is not as extensive and definitive as the next set of qualities. Partly this seems to be because of the more intangible nature of these qualities which makes researching them more challenging. These qualities include:
- Visual permeability (being able to see into and through a space)
- Sense of place (distinctive sense of local character)
- Pedestrian scale (design of streets and buildings are clearly oriented to the scale of the pedestrian)
- Façade continuity (façades form a continuous and coherent street wall)
- Natural surveillance (the creation of space that is well overlooked by surrounding buildings)
- Presence of street-level activity
- Good street lighting (where streets are well lit to improve street safety, but not over-illuminated, thus creating light pollution)
- A denser street network (avoiding large urban blocks in favour of smaller ones)
- Low vehicular traffic speeds
- Low neighbourhood noise
- Presence of public spaces that are attractive, welcoming, comfortable and adaptable
- A positive, sociable threshold between public and private spaces (such as front gardens, porches and external seating areas)
- Retention and integration of built heritage into new development
- Natural features and a diverse ecosystem integrated throughout the built environment
- Architectural quality and beauty in the built environment
Aspire to create attractive, welcoming, comfortable and adaptable public spaces
Whilst some of these, for example façade continuity or traffic speeds are relatively easily specified, most need more careful interpretation in the light of local circumstances and this will lend itself to greater control through the informal tools of design governance, for example through design review, or the preparation of design guidance. They are therefore likely to be ‘aspirational’ rather than required qualities.
Step four: require
Finally, there is a VERY strong positive association between place derived value of all types and six final key qualities:
- Greenness in the built environment (notably the presence of trees and grass, water, and high-quality open space)
- A mix of uses (diversity of land uses within a neighbourhood)
- Low levels of vehicular traffic
- Pedestrian- and bicycle-friendly design (including well-connected, safe pedestrian paths and bicycle routes passing through a high- quality local public realm)
- Use of more compact patterns
of development (that are well connected, less sprawling and not fragmented from other urban areas)
- Convenient connection to a public transport network
Require a mix of uses
These can be seen as first order highly desirable qualities that also happen to be very tangible and objective and therefore measurable. By implication, if the will is there, they can be readily articulated and specified by policy makers through the same formal tools of design governance as the qualities to be avoided. The high standard of proof required to determine that these factors ‘are good for us’ means that there are relatively few of them. As such they can and should be specified in a manner that (suitably adapted to local circumstances) ‘requires’ their delivery.
Given the strength of the evidence, policy makers, developers, and built environment professionals would be remiss if they failed to make the pursuit of a high quality built environment a top priority. They should take very seriously the sorts of qualities that are systematically shown to add value: economically, socially, environmentally and as regard health outcomes.
Fortunately, this is a field of knowledge about which we know a good deal, including the essentials of what makes a good place, and how the way we shape places can add value. None of the constituent qualities of successful places are particularly unique, innovative, or remarkable in any way, yet day to day and place to place they play a role in successfully influencing positive health, social, economic and environmental outcomes. They are easily achieved if we have the will to do so.
Ultimately we can use this knowledge to advance the case for quality when policy, project or investment decisions that affect the built environment are being made. Alternatively, we can ignore it and suffer the consequences. It is that simple!
Matthew Carmona is Professor of Planning & Urban Design at Bartlett School of Planning, UCL
View the original blog post here.
Views expressed by authors may not represent the views of CaCHE.
Date: December 17, 2019 12:00 pm
Author(s): Matthew Carmona
Categorised in: Place