In 2025 I undertook the course Sustainable Cities: An Introduction taught by my fantastic and friendly colleague Dr David Howard. I wanted to share an updated version of the assignment from the course online in case anyone found it interesting.

Is Willowbrook Park a Sustainable Urban Development? 

Introduction

This essay reviews the sustainability of one of the ongoing green-field developments to the North-East of Didcot. Willowbrook park is one part of a major development of around 2,000 homes to the North of Didcot, being delivered by Croudace homes, alongside two other developers. Willowbrook Park was begun before the other developments and is nearly complete, with most sections built and inhabited. The wider development is part of a major extension of Didcot as part of the Didcot garden town masterplan (South Oxfordshire Council, 2017).

The developer claims that “Ecological and environmental aspects of construction are of the utmost importance” (Croudace homes, 2025a: 4). To assess this claim, I will first give an overview of the development in question and its context, provide a working definition of sustainability and then discuss how well the development fares according to the three pillars of sustainability. I will focus mostly on the environmental pillar.

Context

The extension of Didcot takes place in order to meet the acute housing need in Oxfordshire arising due to economic success and rapid population growth. South Oxfordshire has been the focus of a lot of job and housing growth, particularly arising due to research developments at Harwell, Culham and Oxford. As there are green belt restrictions around Oxford, Didcot has been the focus of housing growth due to its location.

Figure 1 Map with Didcot, Railway lines and Location of development marked with an X.

Didcot grew into a town as it is the junction station where the Oxford branch line deviated from the Great Western Railway Mainline (London to Bristol). The Oxford branch was soon connected to the North to allow North-South journeys. As a result, Didcot is a major passenger transportation hub with trains and buses. It is also a logistics hub, with the A34 North-South trunk Road complementing the rail connection.

Sustainability

What does it mean to say that a development is sustainable? This term can be used in many ways and so it is appropriate to ensure that the word is being applied in a meaningful and helpful way. Care should be taken because there are ongoing concerns about the potential for greenwashing by profit-seeking firms, who would get some value from being perceived to be sustainable.

A development exists within a wider context, of course. This complicates the picture because it is the wider context that often matters, and each development cannot change that all on its own. However, a development can make a positive (or negative) contribution to the overall sustainability of a community, region, country, and world.

An early and influential definition was needs-focused, “meeting the needs of the present without compromising the ability of future generations to meet their own needs” (Brundtland 1987). An appealing later definition was that “there is some X whose value should be maintained, in as far as it lies within our power to do so, into the indefinite future” (Barry 1997, 101). This leaves it open what the X should be. Human capabilities are a useful metric for some purposes, and Helm argues that capabilities are what should be provided to future generations (Sen 1980; Helm 2023).

For the purposes of this essay, I propose that the urban environment should… “provide the capability of living well to the present and future generations, while contributing positively to the ability of the wider world to also achieve those aims.” Sustainable developments are those which help a city achieve these aims to a greater extent.

To make the task more manageable I will organise my discussion around the three pillars (Purvis, Mao, and Robinson 2019). I will focus mostly on the Environmental pillar even though there is no implied order or priority between them.

One approach which is positive for sustainability on all three pillars is to achieve a “fifteen-minute city.” This means that all major amenities can be found within a 15 minute walk (Moreno 2024). The development achieves this for some amenities (primary school, convenience store [when opened]), but certainly not all, meaning that many people will drive.

Social Pillar

In terms of social sustainability, as a green field development a new community will need to be formed. Some features should help with placemaking. At the Southern entrance to the development there is a square “neighbourhood park” which also serves as flood abatement infrastructure. A community centre is being built nearby with a public square outside which faces across to a primary school. This should offer a good meeting place (Whyte 1988). Hopefully the future community will find ways to use these flexible and accessible spaces according to their needs and wants (Ellery and Ellery 2019).

Another point that should encourage placemaking is that a lot of the buildings have balconies and are close to the street. This means that residents will be close to passing neighbours, increasing the likelihood of social engagement.

Economic pillar

The strong relatively South Oxfordshire economy is the underlying reason for the development, by attracting new workers to the area. South Oxfordshire benefits from many research and science enterprises in the “Science vale,” particularly those based at Harwell and Culham, employment sites at Milton Park. Didcot is also a dormitory commuter town for major employment centres of Oxford, Reading and London. The development should be economically sustainable to the extent that it relates to these local opportunities. However, the development is not within walking or wheeling distance of very many employment sites.

Many opportunity sites are reachable by car or bike and/or public transport. Two bus routes run through the site and towards employment sites. Didcot railway station can be reached relatively quickly by bicycle. From here trains and buses run to many major urban centres and employment sites.

Environmental

Nature and the built environment

The masterplan for the development retained existing field boundaries, hedgerows, ditches and many trees (See figures 2, 3 and 4). This will help the development to maintain and allow the continuation of local natural processes, ecosystems, species and biodiversity.

Figure 2: A retained field boundary with trees and shrubs.

Blue-grey development

The development is on flat land which was previously considered unsuitable for development due to its position at the foot of the local elevated land and little above the level of the nearby River Thames. Flood mitigation measures were therefore important, particularly since Climate change is expected to increase the intensity of rainfall in the future and therefore increase the likelihood of flooding (Kendon et al. 2025).

Care was seemingly taken to ensure that the hydrological measures would allow the urban and natural to co-exist to some degree. In figure 3 below we see that existing oak trees and a stream with reeds were retained at a lower level of elevation than the newly built roads, paths and housing.

 

Figure 3: natural features and flood mitigation.

Figure 4 features an impound pond at an elevation between that of the housing and the ditch/stream below. The trees and hedges alongside the ditch have been retained, and these form the boundary of the neighbourhood park mentioned above. This is an example of blue-grey-green development, where hydrological structures are built in such a way as to work alongside natural processes (Depietri and McPhearson 2017).

Wildlife [or ecological] corridors are an important feature of a sustainable city, as these provide sanctuary for species and a means to pass safely between different areas without being exposed to predators and vehicles. The continuation of existing hedgerows and ditches, may help provide wildlife corridors in the future. However, mesh fences may serve as a barrier to this. Open fences such as the ones in photo 3 should be less of a barrier.

 

Figure 4: flood mitigation impound pond alongside a ditch with trees and grass surrounding.

Figure 5: View from the neighbourhood park to a dense housing development

Housing sustainability

The developer makes strong claims about their sustainability record, with webpages, brochures and a sustainability framework (Croudace Homes 2025b). From my perspective they do appear to take sustainability much more seriously than their rival housing developers, though that may be to compare them against a low bar. The density of the development is high in some areas, as depicted in Figures 5 and 6, but low in others. I will give my impression having walked around the area.

A major source of greenhouse emissions and pollution comes from the energy used for heating and transport. All the housing appears to offer a parking space with an EV charger. This provides for a future in which cars are electric and thus much less polluting and expensive to run, which is preferable to combustion vehicles. This is increasingly the case as the GB electricity supply continues its rapid decarbonisation (NESO, 2025), with a government target for over 95% clean electricity by 2030 (DESNZ, 2025). On the other hand, vehicles are environmentally damaging to produce and get relatively little use compared to commercial or shared/hire vehicles, and so a more sustainable city is one in which cars are not necessary because everything is within easy walking and cycling distance.

Buildings often have solar panels, though the early houses in the development had one or two on highly suitable south-facing rooves that could have held many more. Subsequent buildings have more, though roof space is still not fully optimised for solar generation. This makes the installations appear as examples of box-ticking for regulation purposes and represent a missed opportunity for clean electricity generation.

In terms of heating, figure 6 contains some examples of heat pump usage. This is by far the most sustainable form of heating as it can run from zero carbon renewable electricity and operates at a positive efficiency level of up to 500% by absorbing heat from environment. However, these examples are sadly rare, as gas heating seems much more common. [Update: One large house appears to have had a large Octopus Energy installation recently, presumably of an Air Source Heat Pump, which may have received a government grant for £7,500 to remove a heating system that was virtually brand new. This points to the economic as well as environmental unsustainability of installing gas infrastructure that will need to be removed and replaced at great expense]. Housing heat efficiency regulatory standards have increased over time, and while the developer may be meeting and possibly exceeding these, they are not seemingly aiming for Passivhaus thermal efficiency standards.

Figure 6: Dense housing with heat pumps and EV charging

Conclusion

Overall, there are many features of the development which are positive in terms of sustainability. Some may have been driven by regulation or the site masterplan, though the developer appears to take sustainability more seriously than rival firms. That said, the development is not a 15 minute city and there are areas in which opportunities have been missed.

References

Online resources

Croudace homes, (2025a) Willowbrook Park Brochure url: https://www.croudace.co.uk/SiteFiles/905/Didcot%20overview%20brochure.pdf downloaded on 01/12/2025

Croudace homes, (2025b) “Sustainability” on website url: https://www.croudacehomes.co.uk/Sustainability [viewed on 12/12/2025]

DESNZ [Department for Energy Security & Net Zero] (2025) Policy paper Clean Power 2030 Action Plan: A new era of clean electricity url: https://www.gov.uk/government/publications/clean-power-2030-action-plan/clean-power-2030-action-plan-a-new-era-of-clean-electricity-main-report

NESO [National Energy System Operator] (2025), “Carbon Intensity dashboard” url:  https://dashboard.neso.energy/  

South Oxfordshire Council (2017) Didcot Garden Plan Delivery Plan https://www.southoxon.gov.uk/south-oxfordshire-district-council/business-and-economy/garden-communities/didcot-garden-town/didcot-garden-town-delivery-plan/ Downloaded on 11/12/2025

Whyte, W.H. (1988) The Social Life of Small Urban Spaces. Municipal Art Society. Available at: https://archive.org/details/CitySpacesHumanPlacesLinks to an external site.

 

Published resources

Barry, Brian. 1997. "Sustainability and Intergenerational Justice." Theoria: A Journal of Social and Political Theory (89): 43-64. http://www.jstor.org/stable/41802067.

Brundtland, Gro Harlem. 1987. "Our common future world commission on environment and developement."

Depietri, Yaella, and Timon McPhearson. 2017. "Integrating the grey, green, and blue in cities: nature-based solutions for climate change adaptation and risk reduction." In Nature-based solutions to climate change adaptation in urban areas: Linkages between science, policy and practice, 91-109. Springer International Publishing Cham.

Ellery, Peter J., and Jane Ellery. 2019. "Strengthening Community Sense of Place through Placemaking." Urban Planning; Vol 4, No 2 (2019): Public Space in the New Urban Agenda: Research into ImplementationDO - 10.17645/up.v4i2.2004. https://www.cogitatiopress.com/urbanplanning/article/view/2004.

Helm, Dieter. 2023. Legacy: How to build the sustainable economy. Cambridge University Press.

Kendon, Mike, Amy Doherty, Dan Hollis, Emily Carlisle, Stephen Packman, Svetlana Jevrejeva, Andrew Matthews, Joanne Williams, Judith Garforth, and Tim Sparks. 2025. "State of the UK Climate in 2024." International Journal of Climatology 45 (S1): e70010. https://doi.org/https://doi.org/10.1002/joc.70010. https://doi.org/10.1002/joc.70010.

Moreno, Carlos. 2024. The 15-Minute city: a solution to saving our time and our planet. John Wiley & Sons.

Purvis, Ben, Yong Mao, and Darren Robinson. 2019. "Three pillars of sustainability: in search of conceptual origins." Sustainability science 14 (3): 681-695.

Sen, Amartya. 1980. "Equality of What?" In The Tanner Lectures On Human Values. Salt Lake City: University of Utah Press.