Digging into the data

I don’t suppose many of you took me up on last week’s suggestion of reading the Greater Cambridge Shared Planning Service’s Annual Monitoring Report (AMR), which was discussed at the City Council’s Planning and Transport Scrutiny Committee on Tuesday.

However, if we are really going to get a full understanding of what’s happening in the area, then this is a very useful way in to seeing what sits beneath the headlines about housing delivery.

Here are three elements which caught my eye.

Neighbourhood plans

(starting paragraph 2.15)

I’ve written previously about the discrepancy in the number of Neighbourhood Plans adopted or under development in South Cambs vs the city. That discrepancy continues to grow. The AMR notes that as of November 2022 there were 21 ‘designated neighbourhood areas’ (preparatory phase) and seven adopted Neighbourhood Plans in South Cambs, compared to a single designated area in Cambridge, in South Newnham.

As at last year’s meeting, I asked officers about why they thought this discrepancy exists. Their answers seem to come back to the fact that a parish council provides a vehicle for taking this work forward, and since we don’t have an equivalent tier of local democracy in the city, there’s no real engine to take this on – although officers are happy to be contacted by residents who are interested in exploring what would be required.

When you look at the wording around the goals of, for example, the Waterbeach or the Gamlingay Neighbourhood Plan, it’s hard to see why residents in the city wouldn’t want to adopt the same approach:

Maybe this will be the year when the tide starts to turn.

Housing density

(starting paragraph 3.17)

The AMR notes that the average density of building in the city (measured in dwellings per hectare, or DPH) was 60% higher for the 615 net additional dwellings completed in 2021-22 than the average for the previous decade: 123 DPH vs 76 DPH. Meanwhile, in the South Cambs, density was lower than the recent average (31 DPH vs 35 DPH).

It can be hard to visualise what a particular density translates to on the ground, but this helpful guide illustrates typical land uses at different densities:

Obviously, we should shouldn’t read too much into one year’s outturn, as it will be the result of whatever particular developments are completed within that year. However, it will be important to be familiar with the broad trend and the implications for the built environment as we move through the process of drafting the new Local Plan through this year.

Community, sports and leisure facilities

(paragraph 3.77)

The context for this part of the AMR is Policy 73 of the 2018 Local Plan, which covers a wide range of facilities under the D1 (community use) and D2 (recreation and leisure use) classes. The intention of the policy is to encourage the delivery of these in suitable locations and to protect existing facilities where possible.

Para 3.77 seems worth interrogating. It tells us that “There has been a net increase of 3241 square metres of D1 (community use) floorspace and a net decrease of 463 square metres of D2 (recreation and leisure use) floorspace in Cambridge in the 2021-2022 monitoring year.” The first step is to put this in context – so let’s use that standard reference point, a football pitch, which is roughly 7100 square metres. On that basis, the city got just under half a football pitch’s worth of ‘community use’ space last year.

But wait. The AMR then goes on to explain that over half (1770 sq m) of that D1 space came from the new award-winning library at Magdalene College. That’s very lovely for the students and staff of the college, but it’s not accessible to, or consistent with, what I suspect you or I would understand as ‘community use’. And that made me wonder: what else was contributing to that 3241 sq m of ‘community use’? So I asked officers for a breakdown and then applied my own interpretation of what would really be understood as serving that purpose, i.e. excluding sites which are only accessible to a particular demographic (university, college, private schools, staff premises):

On that basis – which I freely accept is subjective – the city gained 553 square metres of D1 ‘community use’ space last year. And lost 463 square metres of D2. So that’s a net gain to the city of 90 square metres.

Now again, there are clarifications needed alongside this.

The first thing to note is that the officers have done what was required of them, reporting the total for all facilities which fall within the D1 use class, which as noted above, is a very wide classification. I have no criticism there. But in the context of a city where so much development is carried out by a handful of exclusive gate-keeping institutions, might it be helpful to also report somewhere, even if not in the AMR, on what the ‘real’ figure is?

Secondly, it’s important to know whether the outturn for 2021-22 was an anomaly, or whether it represents a typical proportion of total D1 across an extended period. Officers have very kindly forwarded me the data for the last 10 years (all 550 D1 and D2 records) and I will be digging into that further next week.

Why does this matter?

Well, we know from the AMR is that there has been a net increase of 226,219 square metres of D1 floorspace and 28,962 square metres of D2 floorspace over the period 2011-2022. At face value, those seem like big numbers. But what if (for the sake of argument) we applied this year’s 17% ratio of ‘real’ community space within the D1 class to that 10-year D1 total? That would indicate we’ve actually only added 38,600 square metres of ‘community use’ floorspace (5.5 times our notional football pitch) in a decade during which the city’s population grew by 20,000 inhabitants and housing density increased.

I’m sure there’s a lot of room for debate about how further calculations might be done, once you step away from the black-and-white proforma of statutory reporting. I know the pressures on officers’ time, and I can see that subjective assessments might be prone to challenge. But I do think we have to be a bit more curious about what lies beneath the numbers we’re presented with.

And maybe that would go some of the way towards helping us properly understand why the promised benefits of the city’s growth don’t always feel like they are being delivered.