Medium density housing – how to deliver greater choice
Addressing challenges facing the delivery of medium density housing
Tibbalds have carried out a short piece of research looking into the key challenges facing the delivery of medium density housing across the UK through literature review, case studies, and interviews with built environment experts.
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- Office for Place
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- Project Leadership
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- Training and research Urban design advice
Stakeholders pointed out that many new housing developments can only achieve an average of 40 dwellings per hectare (dph) on brownfield sites or exceptional, well-connected greenfield sites. This is largely due to local policies concerning parking, roads, privacy, and amenity space.
Outside of cities and town centres, current and well-established housing delivery models in England primarily deliver low-density housing. This mostly consists of 2-3 storey detached and semi-detached houses, providing below 40 dwellings per hectare (dph). Such developments are recognisable in many suburban or 'new town' areas. Higher density housing in established 'urban' contexts also tends to follow relatively established models and delivery predominately high-rise apartment blocks. They are mostly over 7 storeys and result in dph values of over 100 dph.
These types of development represent opposite ends of the density spectrum, leaving a significant gap - the ’missing middle’. A variety of development types fall into this category, often reflecting a range of heights, house types, and dwellings per hectare values that don’t fit neatly into low or high-density models.
The term 'medium density' therefore addresses this middle ground encompassing developments which are:
- 3-6 storeys in height (with the upper limit of 18m informed by building control fire-safety guidance, Approved Document B)
- house types, including flats, apartment blocks, townhouses and maisonettes and other urban family house types
Tibbalds has recently completed a short piece of research aiming to ascertain where, how and by who the medium density is currently being delivered. Commissioned by the Office for Place before its closure in November 2024, the report will now form part of the evidence base that MHCLG may wish to draw on.
It intended as the first step to understanding the challenges and opportunities in delivering medium-density housing nationally. We drew on case studies and insights from a range of stakeholders to highlight key aspects of delivery, viability, design, and planning that provide both challenges and opportunities for delivering medium-density housing.
A key finding of the study, which will not come as a surprise, is that medium density developments are scarce and mostly developed on complex brownfield sites. It is mostly SME developers that take up the challenge and seek to broaden the housing market.
This article contains some of the finding from the research and identifies the challenges that we as an industry need to overcome to be able to deliver medium densities at scale.
What is the opportunity?
The UK government is facing a significant challenge in urgently addressing the country’s housing shortage, while simultaneously delivering on its net zero commitments. Medium-density housing offers one way to achieve both. It also provides a means of promoting healthier and more environmentally friendly lifestyles through compact, sustainable developments. This is supported in the NPPF 2024’s emphasis on the need to use land efficiently (Paragraph 125) and setting out means of identifying appropriate densities (Paragraph 129).
Delivering ‘optimised’ housing densities offers a clear opportunity to address housing pressures through a coordinated strategy. Medium-density developments can deliver efficient use of land and broaden the housing offer to meet the needs of our communities.
However, significant challenges remain. In 2021-22, the government’s statistics estimated average density of new residential development was 31 homes per hectare, a decrease of 11 compared to 2020-21. There are considerable cost, viability, skills and labour challenges facing housing delivery of all types across the UK, however this impacts the delivery of medium-density housing disproportionately, because these types of developments are bespoke, atypical and not supported by prevailing housing-deliver models.
What we found
1. A cycle of limited evidence restricting atypical development types
The relatively small number of successful medium-density developments across the country leads to a lack of sufficient precedents. The lack of financial data from comparable developments impacts commercial decisions from agents and surveyors, restricting the finances available to enable medium-density development to be built at scale.
However, there is a growing catalogue of exemplary development across England that deliver medium densities through innovative housing models, such as at the much-celebrated Malings in Newcastle, Brabazon in Bristol and Climate Innovation District in Leeds. This is increasingly contributing to the evidence and precedents available and provides reference projects for surveyors and investors to be more confident when assessing medium-density developments. Currently, the use of value and viability benchmarks, set by lower-density, suburban or high-density housing works against their delivery of medium-density developments.
2. A challenging planning context
Where medium densities have been successfully delivered, this is often due to the perseverance of developers, planners and design teams in successfully justifying a departure from local policy and guidance.
Local planning policies and processes are largely formulated around the predominate development forms, suburban family housing and high-density flatted development. The unintended consequences are that these policies don’t support medium densities and even set barriers to the delivery of sustainable development forms. This includes favouring street layouts and block types consistent with lower-density and car-dependent developments, such as favouring front-of-door or on-plot parking; setting minimum back-to-back distances requiring the provision of large, private rear gardens and a narrow view on how private outdoor amenity can be provided.
The local interpretation of national regulation and legislation can similarly place challenges for certain medium-density housing types. House types such as maisonettes and walk-up apartments deliver medium densities and are often more cost and space efficient than apartment blocks with lifts and corridors. However, it is challenging to achieve a sufficient proportion of accessible and adaptable units through these types.
Similarly, national legislation and guidance through the NPPF and Manual for Streets seeks to give priority to pedestrian and cycle movements, and locating development in accessible locations. However, site allocation processes don’t always follow this through, leading to isolated sites without public transport. Car-dominated developments do not lend themselves to medium-density housing due the applied car-parking standards and the associated land-take.
As national and local policies are required to be based on robust evidence, this evidence is often based on the existing development patterns. Thereby, creating a backward-looking policy position that ingrains the existing development types and is not always supportive of innovation and change.
The length, complexity and expense of the planning process itself can also act as a deterrent for innovative or different types of housing development. While this impacts all types of development, it is more pronounced in medium-density projects due to their:
- Smaller scale of development
- More complex and constrained sites
- Need to challenge local policy and interpretation of legislation
- More resource-intensive design process
- Greater challenges in accessing capital funding
- Greater challenges in balancing viability with housing targets and unit mixes to support sustainable communities
3. Variation in housing types, market audience and future communities
While there is often conjecture around the assumed lack of market appetite for medium-density house types, our research has highlighted that there is in fact a diverse market, with people open to alternative housing models that offer sustainability, community, and convenience.
Medium-density house types have proved attractive to a wide range of occupiers including: younger first time buyers in their 20s or early 30s; individuals or couples purchasing in their mid-late 30s with a view to living there for a good few years; couples keen to start a family or with children in their early years; parents whose children have moved away from home; and older people who are seeking the sense of community and convenience that denser, compact housing provides them.
Stakeholders highlight that the reliance on proven market success to inform future developments keeps large developers focused on low-density homes. As a result, medium-density housing struggles to secure investment, with appraisers and lenders hesitant to support non-standard house types with lesser-known values.
4. Overlapping commercial challenges
SME developers are leading the way in delivering medium-density housing across the country, providing a more nimble and responsive approach to the specific site constraints and design responses that such development requires. These developers are often making medium-density work commercially through implementing a regeneration and placemaking approach that foresees a longer-term return on investment in ‘neighbourhoods’ rather than developments.
However, the upfront costs, investment, and financing challenges facing medium-density development do not reduce in proportion to scale. This makes medium-density development commercially difficult, regardless of the site context and size.
5. Infrastructure as enabler
The potential for introducing medium densities is largely informed by proximity to key infrastructure – supporting compact, convenient and sustainable lifestyles. Delivering new medium-density developments or optimising the density in established neighbourhoods is primarily contingent on access to public transport and day-to-day local services. Similarly, the long-term success of these developments and neighbourhoods is bolstered by early investment in both social and cultural infrastructure.
Interviews emphasised that the layout of these neighbourhoods encourages social interaction across different groups. House types like stacked maisonettes or terraces require neighbours to cross paths regularly, while in apartment blocks like those at the Malings or Trent Basin, shared spaces like bin stores and communal gardens foster interaction. ‘Post-occupancy evaluations of the Mailings highlighted that the sense of community and connection with neighbours is one of the development’s key strengths.
Summary
Evidence shows that medium-density development, as defined above, is occurring nationwide, even in areas with challenging viability. However, these projects are typically led by SME developers and remain exceptions. The research identifies several barriers to expanding the market share of medium-density developments. Our recommendations aim to gather more information and address these challenges to make medium density a standard development option.
To support a broader housing offer, the building industry needs to:
- Bring together different professional organisations around the topic of medium-density to address barriers and challenges, including RICS, RIBA, RTPI, Homes England, DFT and New Towns Task Force.
- Promote and encourage partnerships /collaboration between SME and national housebuilders.
- Share knowledge of medium-density housing types, with comparable construction costs, benchmark values and a commentary on their wider benefits (including post-occupancy surveys).
- Share policies, local plans and their evidence that are supportive of medium densities in the appropriate locations.
- Demystify density: explain how density relates to existing places, such as historic market towns, and how they relate to different scales and house types. Support officers and members to make informed decisions on the wider benefits of medium-density development.
- Highlight opportunity created by devolution for funding and housing to integrate housing delivery with transport and other infrastructure as well as opportunities created through delivery of new towns.
