Danielle Densley Tingley, Hadi Arbabi, Helen Fairclough, Jannik Giesekam, Charles Gillott1, Miriam Graham, Kersty Hobson, Shreenij Maharjan, Rick Lupton, Maria Sharmina-Written evidence (NTP0031)
1 University of Sheffield, 2 University of Strathclyde, 3 Cardiff University, 4 University of Bath, 5 University of Manchester.
Policy recommendations
● Adaptation and reuse of existing buildings, infill and densification would have lower environmental impacts than the creation of new towns, and should be considered as a policy priority before the development of new towns.
● New national regulation to limit embodied carbon and encourage circular economy approaches is essential to minimise the significant environmental impacts of new towns and wider built environment development.
● Sustained and authentic public participation in the planning and development of new towns is fundamental to creating desirable, sustainable places and should be prioritised.
● Future modules of the ‘new towns’ inquiry should consider 1) different ways to construct communities, i.e. more shared amenities to reduce resource consumption and embodied carbon emissions; 2) the long-term adaptability of new towns to ensure these can meet changing needs in the future, both of individuals and of a changing climate.
Introduction
This submission is by researchers affiliated with the BuildZero consortium funded by the UK Research & Innovation (grant reference EP/Y530578/1). The authors have expertise across whole life carbon measurement and reduction, circular economy, industrial ecology, urban planning and scaling, participatory planning and research, and business models. Our expertise and work in these areas is used to form the responses to a number of the committee’s questions below. Our answers are structured in response to each of the committee’s questions, numbered in accordance with the committee’s call for evidence.
1. What do you anticipate will be the most significant impact(s) of the Government’s proposed new towns?
The whole life carbon impacts of the proposed new towns will be significant. These incorporate the emissions from the extraction, manufacturing, transport and maintenance of materials to build new homes and the supporting infrastructure, as well as the operation/use of these. According to the UKGBC, embodied carbon forms a quarter of whole-life carbon emissions from UK buildings, with this expected to rise to more than half by 2040 and almost three quarters by 2050. When the New Homes Standard comes into force, if it bans gas boilers, as is expected, this will significantly reduce the operational carbon of homes, increasing the relative impact of embodied carbon.
Meeting national housing targets through new construction, and thus new towns, is fundamentally incompatible with the UK’s legally binding carbon reduction targets. We estimate that the embodied carbon from the construction of 1.5 million new homes is 5-9% of the UK’s total carbon budget for the same 5-year period. Instead, development should prioritise adaption and reuse of existing urban buildings first, as discussed further in Q10-12 below.
The development of New Towns, as opposed to developing within existing towns, will create additional impacts from the development of new supporting infrastructure, e.g. transport, energy and water networks. Evidence shows, across various urban systems, that larger cities tend to be more efficient in their per capita needs of infrastructural elements due to population agglomeration effects, eg, total length of roads, and energy use - both domestically and for transport. The current plans for New Towns of at least 10,000 homes, which largely appear to occupy fringes of existing urban areas, are likely to miss the opportunities from agglomeration effects, which could be achieved through in-filling and densification of existing centres.
In addition to emissions associated with the houses themselves, the average new town with a population of 23,600 (based on an ONS 2.36 household size and our scaling estimates) is likely to require an average of 122.4km in total length of roads which could result in whole life emissions of 108-247ktCO2e over a 40 year lifespan just in provision and maintenance of the surface infrastructure needed. This is in contrast to an average of 70km in additional roads required when increasing densities by 10,000 homes in urban centres of roughly 500,000 people.
There will also be significant impacts on resource extraction and land use to construct new towns, which will have wider environmental implications, including biodiversity impacts. These collective impacts could be minimised through the adoption of circular economy principles and requirements to minimise whole life carbon, but policies are needed to support this, see our response to Q7 for further details.
a) Over what timescale do you expect these to be realised?
There will be short term environmental impacts that arise during the construction of new towns - resulting from resource extraction and their embodied carbon. There are also longer term environmental impacts that arise from operational carbon, maintenance and upgrade, transport and the long term resilience of these towns (particularly if this is not effectively considered in design).
3) What, if any, are the barriers to the development of good quality new towns?
There are a number of barriers:
i) Clear guidance on what ‘good quality new towns’ look like is lacking, particularly with regards to whole life carbon, resilience and connectivity. Please see our response to Q1 for detail on embodied carbon, and our response to Q10 on the importance of prioritising connectivity in master planning. If development is not coordinated through a vision and a master plan, critical mass benefits might not be realised thereby increasing costs.
ii) Our engagement with the housing construction supply chain on the Future Homes research project, shows that among the top barriers to sustainable construction are shortages in workforce and skills to build high quality new homes. This barrier includes fragmented provision of training; policy uncertainty putting off private investment in skills; and competition for skilled workers with other sectors (Smith & Sharmina, 2025).
iii) We have also found an over-emphasis on operational carbon metrics in delivering new housing, at the expense of affordability, comfort and even health (Smith & Sharmina, 2025). For example, new-build policies do not mandate mitigating the impacts of energy efficiency measures and heat pump installations on indoor air quality, noise and temperature, and hence these aspects are often disregarded in construction (ibid.).
4) What current policy channels exist to deliver new towns, and are they sufficient? If insufficient, what policy changes would facilitate their development?
There is a lack of policy to deliver the sustainable development of new towns. Specifically, there is no regulation of the embodied carbon of new building development and no measures in place that would incentivise incorporation of circular economy principles in order to reduce resource impacts from New Towns now, and improve resource security in the future. We highlight the potential environment impacts in our Q1 response, and potential policy approaches in our Q7 response.
5. What do you think future modules in our inquiry should examine when considering what makes a successful new town?
Developing new towns introduces a key opportunity to rethink how we construct places that have low environmental impacts - in their construction and throughout their life and genuinely form new vibrant communities of people.
Future modules should explore approaches, both in practice and in theory, to create new low-impact communities. This should include:
i) Shared community amenities, which can reduce individual, private space needs and thus overall resource requirements. Examples of these include spare bedrooms, large hosting kitchen and dining facilities, shared gardens, as in the Low Impact Living Affordable Community (LILAC) in Leeds. Such community amenities can be managed via an online booking system allowing residents to seamlessly plan and use the amenities as per their individual needs. They can also enable new homeowners the flexibility to opt for smaller, more affordable homes, but with diverse amenities. Furthermore, the use of communal spaces promotes social interaction between residents. Alternative ownership models such as those operated in LILAC, e.g. Mutual Home Ownership Societies should also be explored in future modules.
ii) Car free housing, where developments are designed around people, not vehicles, with excellent public transport and local car clubs to facilitate mobility with lower environmental impacts. The INFUZE research project explores this further.
iii) Long term adaptability of developments, to ensure these New Towns can meet changing needs, of both individuals and a changing climate. Research has been undertaken considering the adaptability of structures and homes, although more work is needed to consider how communities would want their homes to be able to adapt. There is also limited work on the adaptability of mechanical services, which both have higher replacement rates and will be expected to respond to a changing climate, e.g. to prevent overheating of homes.
7. How can central Government support the planning and delivery of new towns?
National policy that requires consistent assessment and regulation of whole life carbon is essential to ensure new towns are delivered sustainably.
This policy should sit within planning regulations, where early stage decisions are made and the potential for emissions reduction is greatest. This approach is currently implemented by a small number of other Local Authorities (Graham et al. 2025). Assessment as part of Building Regulations to ensure construction meets whole life carbon limits is also important, with the Part Z policy position paper having strong industry support.
Our on-going research highlights the need for a national approach to whole life carbon regulation:
i) Workshops with 25 Local Planning Authorities (LPAs) have highlighted that variations between LPAs in reporting formats, carbon limits and the scale of development to which these limits apply can be burdensome and inefficient for developers who work across LAs. There are also challenges in setting limits due to the lack of a consistent national whole life carbon dataset. We found that there is strong appetite among LPAs for a coordinated national approach to whole life carbon regulation.
ii) Embodied carbon is distributed across LPAs, meaning national regulation is required for maximum reduction in emissions:
Figure 1: Modelled cumulative proportion of national embodied carbon emissions associated with cumulative proportion of English LPAs
iii) National regulation could achieve significant embodied carbon reductions, with the potential to halve current levels in the longer term:
Figure 2: Projected annual embodied carbon emissions, unregulated emissions (mean kgCO2e/m2, with error bar showing potential range of unregulated emissions), regulation in line with draft LPA policy (500 & 600kgCO2e/m2 residential and non-residential buildings), and longer term aspirational LPA regulation levels (300 & 350CO2e/m2 residential and non-residential buildings)
9. What role should community engagement play in developing and planning new towns?
Community engagement is critical in the development and planning of new towns. There is around 70 years of documented insight into the importance of community engagement in all forms of spatial and social planning. However, as Sherry Arnstein’s ‘ladder of participation’ illustrates, much of what passes as community involvement in planning (what she labelled as ‘consultation’ and ‘informing’) are categorised as ‘degrees of tokenism’. Instead, it is only ‘partnerships’ or forms of ‘delegated power’ that, according to Arnstein, constitute authentic and impactful participation. The latter is important, as decades of research has underscored how meaningful participation can have positive impacts on planning outcomes. But when done poorly and smacking of ‘tokenism’, community engagement planning processes can increase dissatisfaction and distrust, particularly when participants' feel unable to influence decisions (Brown and Chin, 2013).
Research has, however, noted that public participants can gain a ‘sense of shared authorship…through active involvement in the (design) decision-making process’. There are diverse forms of innovative participatory methods (e.g. Sanoff, 1999) that can be utilised to create shared visions and values from a wide range of citizens, not necessarily exclusively future residents of particular New Towns. And as such, sustained and authentic public participation in developing and planning new towns is fundamental to creating desirable and sustainable places.
10. What elements should be prioritised in the strategic master planning of new towns?
Three key elements should be prioritised in the strategic master planning of new towns:
i) Adaptive reuse, retrofit and densification of existing building stocks. ‘New towns’ present an opportunity to regenerate and expand existing, underutilised building stocks. As we highlight in a previous evidence submission and in Q1, an assumption that additional homes should be provided by new construction is not compatible with UK carbon budgets. Research has shown the existing stock likely has capacity to be vertically extended, and we estimate existing permitted development rights have the potential to provide 176km2 of new usable floorspace (equivalent to 1.8m average-sized homes). We also highlight in our Q1 response the agglomeration benefits of densification. Thus it is critical we make effective use of existing stocks alongside new construction. This is potentially also a more feasible approach to meet housing targets.
ii) Mandatory whole life carbon assessment and limit setting to ensure the development of new towns are compatible with UK carbon budgets. We expand on this idea in our responses to Q1 and Q7.
iii) Effective, low whole life carbon mobility solutions. Research has shown transport and mobility challenges are persistent across scales in the UK outside of Greater London, with mobility and density shown to be closely linked. It is thus critical that mobility solution planning is embedded within the development of new plans, e.g. ensuring active travel solutions and public transport are provided as a priority. Essential amenities and services should be provided within the towns with careful consideration of public transport connections to amenities within and between towns.
11. On what basis, and using what metrics, should the location and size of new towns be decided?
When considering the size of the towns, the number of dwellings should be decided based on demand. For example, the planning of the new towns and the wider industrial strategy should be coordinated to locate industrial developments requiring large numbers of workers close to new towns. Once demand is determined, the physical size should be chosen to allow for high-density development which research shows typically results in lower urban carbon emissions.
We believe that there is scope to deliver a significant proportion of the new homes required in the UK by making use of existing stock. For example, through schemes of coordinated repurposing, extending and adaptation of the existing under-utilized stock in a particular area, with strategic additional construction only where the existing structures cannot meet requirements. This approach typically results in significantly lower carbon emissions, with work showing this for vertical extension, and retrofit schemes. The latter piece of work shows that demolition and new construction very rarely results in a lower whole life carbon solution.
Where existing building stock is wholly unsuited to repurposing, there can still be a benefit in locating new town sites close to these locations. Existing buildings can be deconstructed and the component parts re-used to build different structures. Whilst this incurs more carbon emissions than reusing a building in place (due to transport, processing etc.), it still requires much less energy than recycling the material. As transport of material is a contributor to emissions, locating the new towns near material points of origin would have carbon benefits. Reuse hubs for storage and processing of the elements should also be located nearby.
12. To what extent can the proposed new towns act as a model for general housing development across the UK?
The generation of residential units through the development of new towns reiterates the concerning notion that housing delivery must be met through new construction. This is not the case. It also risks providing housing at a low residential density, with poor access to key services, amenities and transport infrastructure. We would recommend as an alternative that focus instead is placed on the adaptive reuse and retrofit of built assets within existing urban centres.
Where new towns are to be developed, this introduces the opportunity for new legislation to support sustainable development across residential and non-residential construction. This includes the mandatory assessment and regulatory limit of whole life carbon emissions, the potential environmental benefits of which are highlighted in our response to Q7.
11 May 2025