The Density Debate

Several planning decisions (specifically refusals) that have occurred during 2023 have been result of the introduction of ‘beauty’ as a central theme of the revised NPPF, published in December 2022.

This has in some cases conflicted with another NPPF theme, density – or more specifically, ‘gentle density’. The notes which accompany the NPPF state that the Government will deliver ‘enough of the right homes in the right places with the right infrastructure, ensuring the environment is protected and giving local people a greater say on where and where not to place new, beautiful development…specifically, this includes changes to…promote more beautiful homes, including through gentle density’.

The NPPF, 'beauty' and ‘gentle density’

The changes to the NPPF were in large part a response to a rebellious group of anti-development backbench Tory MPs who threatened to torpedo the progress of the Levelling Up and Regeneration Bill. And so some big-ticket changes (such as removing mandatory housing targets and tightening up on Green Belt development) were made.  It would seem, with the inevitable consequence if not explicit the intention of reducing housebuilding.

On this basis, many practitioners question whether the rather vague and unquantifiable concepts of 'beauty' and ‘gentle density’ were thrown in as a means of stalling proposed new developments for political purposes. For stall them they will; they are terms open to such subjective interpretation that they will tie decision-makers in knots even more than they already are. 

To understand whether 'beauty' and ‘gentle density’ can help, rather than hinder, the quality and quantity of new developments requires a definition of both – as neither have had a place in the planning lexicon until now. That’s where the problems start. ‘Density’ is relatively straightforward as it can be measured in quantifiable terms; a relatively simple function of homes and site area. ‘Gentle’ means very little in a planning context but its function, on any plain reading, is clearly to limit density rather than increase it.  The deceit in the wording is it purports to enable a higher volume of housebuilding, while also giving leeway to appease the 'beauty brigade’ as necessary.

'Beauty' however, is even more problematic in planning terms: it is subjective, unquantifiable and  very much in the eye of each beholder.

The notes which accompany the NPPF make some attempt to quantify ‘gentle density’: they state that, ‘Small sites play an important role in delivering gentle density in urban areas, creating much needed affordable housing, and supporting small and medium size (SME) builders’. It goes on to be more specific about density, ‘Local planning authorities should identify land to accommodate at least 10% of their housing requirement on sites no larger than one hectare; unless it can be shown, through the preparation of relevant plan policies, that there are strong reasons why this 10% target cannot be achieved.’

The NPPF also places renewed importance on upwards extensions: ‘Building upwards in managed ways can help deliver new homes and extend existing ones in forms that are consistent with the existing street design, contributing to gentle increases in density… local planning policies and decisions should consider airspace development above existing residential and commercial premises for new homes. This includes allowing upwards extensions where the development would be consistent with criteria relating to neighbouring properties and the overall street scene, as well as being well-designed and maintaining safe access and egress for occupiers.’ More specifically, it encourages the introduction of mansard roof windows: ‘In some locations, local planning authorities have been reluctant to approve mansard roof development, as it has been considered harmful to the character of neighbourhoods. As a general approach, this is wrong - all local planning authorities should take a positive approach towards well designed upward extension schemes, particularly mansard roofs. It is proposed that a reference to mansard roofs as an appropriate form of upward extension would recognise their value in securing gentle densification where appropriate.’ In my view, this continued idea that building mansard roofs, or indeed the fascination with ‘airspace’ development can make any significant dent in the housing shortage is a wishful/fanciful case of burying heads in the sand and a means of avoiding the tough conversation about proper development on the ground.  There is scant evidence that airspace development is actually working.

The role of 'beauty' and ‘gentle density’ in national planning policy

It seems a step too far for planning policy to identify specific architectural features such as mansard windows as ‘well designed’ and to state that considering them harmful to the character of neighbourhoods is ‘wrong’, as it is commonly accepted that whether any architectural feature is ‘right’ or ‘beautiful’ depends upon the context.

My own view is that good design is closely linked to good land use. In most situations, and especially in urban areas, density has many advantages. We have an indisputable shortage of homes which is best addressed by providing an optimal number of homes on all available land; that’s Chapter 11 of the Framework which seeks to make efficient use of land.  . Doing so helps create a mixed and balanced community, increases the potential for a range of facilities in close proximity, is economically advantageous (allowing resources to be spent on services and amenities) and can facilitate greater variety of uses, such as live/work and co-living. Denser schemes also have the potential to be more sustainable, not least in terms of sustainable transport, if located close to public transport or withing easy each of local services. Developable land, especially in cities such as London where I am based, is a scarce resource and it is essential that potential development capacity is not wasted.

The London Plan, 'beauty' and ‘gentle density’

The London Plan captures this well, and through a design-led approach already encourages density, specifically through Policy D3 (Optimising site capacity through the design-led approach), D6 (Housing quality and standards) which is closely linked to the Plan’s design polices D1 (London’s form, character and capacity for growth) and D2 (Infrastructure requirements for sustainable densities). Policy D1, specifically, includes principles relating sustainable, well-designed places that optimise development opportunities through good growth; Policy D2 concerns ‘appropriate’ scale, height, density, layout and land uses, in order to ensure that the most efficient use of land is made.

The criticisms levelled against greater density are largely irrelevant in London and other cities. Unit sizes are rarely impacted by density requirements, since policies (D6 again) set out minimum floor space requirements (50 square metres for a one bedroom unit).

'Beauty' and ‘gentle density’ in practice

Other criticisms levelled at higher density include the visibility of tall buildings, specifically from protected locations such as historic parks and AONBs. There can also be a perception that high density leads to overcrowding and slums. On these two points, the argument returns to meeting policy requirements. Firstly, tall buildings have a role to play in cities, helping people navigate through the streets by providing reference points and emphasising the hierarchy of a place such as its main centres of activity, important street junctions and transport interchanges. Tall buildings which are of exemplary architectural quality, can make a positive contribution to skylines and are valued as a part of a city’s identity. Of course they can also have detrimental visual, functional and environmental impacts but this too can be controlled by processes set out in planning policy, as it is in the London Plan.

Regarding the suggestion of overcrowding, the densification of town centres is encouraged in policy because it brings much needed vitality and footfall to areas such as high streets which may be suffering from under-investment and reduced use as a result of social and economic change. In such cases, higher density can enliven and enrich a neighbourhood.

Lessons from London

There is much that local authorities across the country, specifically urban councils, can learn from the London Plan. The document takes a rounded approach to the way neighbourhoods operate, putting in place policies which ensure that they work not only more space-efficiently but also better for the people who use them. This often means creating places of higher density in appropriate locations to achieve maximum benefit from limited land, encouraging a mix of land uses, and co-locating different uses to provide communities with a wider range of services and amenities.

The London Plan describes how high-density, mixed-use places support the clustering effect of businesses known as ‘agglomeration’, which maximises job opportunities. High density can provide a critical mass of people to support the investment required to build the schools, health services, public transport and other infrastructure that neighbourhoods require. It can place local amenities within walking and cycling distance and make public transport options easily accessible.

 For residential development it is particularly important to scrutinise the qualitative aspects of the development design described in Policy D6. The higher the density of a development, the policy says, the greater this scrutiny should be of the proposed built form, massing, site layout, external spaces, internal design and ongoing management. This is important because such elements come under more pressure as density increases.

High density and high buildings are not necessary synonymous. That said, the more airspace is utilised, the more land remains available at ground level as an amenity. Policies which create an obligation for developers to provide high quality open spaces include the London Plan’s Urban Greening Factor (UGF). This guidance requires every local authority to create its own greening strategy and all major developments to include urban greening as a fundamental element of site and building design. It introduces the UGF calculator a means of evaluating the quantity and quality of urban greening in a development proposal.

Is there a link between 'beauty' and gentle density?

Both beauty and density are dependent on context, but the similarities end there.

In fact context is one of the many features which demonstrates why the two cannot be considered synonymous. Poundbury, the Duchy of Cornwall’s experimental pastiche development on the outskirts of Dorchester exemplifies this. At Poundbury, Georgian architecture predominates. Georgian architecture may represent the very best in design to some; to others the repurposing of a centuries-old style is regarded defeatist, retrograde, even ‘Disneyesque’. Similarly Georgian architecture divides opinion on density grounds. To me as a Londoner, homes of just three storeys, with generous gardens both front and back represent low density. To a resident of a 1970s bungalow on a generous suburban plot it would represent high density.

Perhaps schemes such as Poundbury will be effective not only in encouraging NIMBYs to accept development, but also to encourage them to accept higher density. But this only works in those areas where the average density is lower than a typical neo-Georgian development. Take that approach in London and the perfectly acceptable densities currently achieved will be lost, homes will become increasingly scarce, house prices will sky-rocket and local centres will become desolate and unviable.

'Beauty' and ‘gentle density’ in a regional context

Every local authority must judge density within its own context, just as the London Plan has inspired London boroughs to do: another argument, were one needed, for regionally-led planning policy.

But a national document such as the NPPF has no role in prescribing either beauty or maximum density across all contexts, were it even possible to do so. My preference is to avoid tinkering with policy when the likely outcome is at best uncertain and at worst, politically motivated. We have enough uncertainty in the planning at present. Constant change will only intensify uncertainty and slow down the much needed provision of new homes, amenities and infrastructure.

I would like to think that these changes would have little bearing on my work because, working with my colleagues in Boyer’s Design team, we already produce schemes which are well designed and make good use of available land. But I fear that tenuous terms such as 'beauty' and ‘gentle density’ despite meaning very little in planning terms, have the potential (as has already been seen with the now infamous Berkeley scheme in Kent) to result in major schemes being called in and refused permission, exacerbating our current housing crisis.