How many more homes could we squeeze into London’s housing estates?

London’s council estates are increasingly considered a valuable source of additional housing supply, primarily through densification of existing sites. The number of estate redevelopment schemes being undertaken in the capital has doubled over the past decade.

Yet despite this emphasis on estates as a source of housing supply, we know surprisingly little about the location, size, and density of the capital’s estates. Here at Centre for London, we decided to explore this further.

We undertook an analysis of large estates (those with over 200 dwellings) in four London boroughs: Barking and Dagenham, Hounslow, Lewisham, and Waltham Forest. Here’s what we found.

Large estates are generally as dense as, or denser, than their surrounding wards.

In all four boroughs, estates were generally denser than their surroundings. With the exception of those in Lewisham, large estates were roughly as dense as, or denser than the wards they are part of.

This is not to say that these estates constitute the best possible use of land – London’s housing challenge requires higher densities across the city. But it does highlight that, in three out of the four boroughs, the density of large estates is not significantly lower than that of the surrounding area as is often assumed.

So what would happen if we turned the dial up, redeveloping estates at the maximum densities specified in London Plan policy?

To generate an estimate, we tested two scenarios: one in which estates were densified to the “urban” density of 145 dwellings per hectare (dpha), and the other in which estates were densified to the “central” density of 210 dpha. Our estimates of course come with some methodological limitations, given that we mapped estates by eye, calculating density by gross rather than net area.

Densifying estates could lead to a lot of additional housing

There are modest gains to be had by densifying estates to “urban” levels – in the four sampled boroughs, densifying estates to the upper limit of the urban level could provide around 10,000 new homes.

Over twice as many homes could be achieved by building to “central” density levels. This would supply at least 50 per cent of the Greater London Authority’s 10 year new homes target in three of the four boroughs.

But introducing “central” level densities to large estates in outer London boroughs would likely involve major changes to neighbourhood characteristics, and would need to be carefully considered in both the design and community consultation.

Estate densification is a long-term game, and one that requires a serious amount of investment.

Our findings indicate that we could see an uplift of between 80,000 (“urban” level) and 160,000 (“central” level) homes in London’s large estates through densification. But these numbers come with a range of caveats.

It would take around 10 years to get all these projects started, with extensive community engagement and careful design required to ensure their success, and another 10 to complete them. In many cases, particularly in outer London, projects would also require subsidy to make them viable – a n issue we explore further in the Another Storey report.

So what did our analysis of large estates in these four boroughs show us? We learned that estates do offer some scope for densification, even though realizing the potential is a long-term process, needing significant investment. Estate densification is not the single answer to London’s huge housing supply challenge – but it should form one element, alongside densification of other land uses across the capital.