Brownfield sites
Brownfield sites are plots of land that have previously been developed but are not currently in use. Recent analysis suggests more than 1 million houses could be built on brownfield sites across England.
We’re working with local planning authorities to improve the quality of data on brownfield sites, turning what they publish into a national dataset. Join the conversation on our GitHub issues pages if you’re interested in brownfield site data.
View the data we’ve collected on our map.
Current areas of investigation
We’re exploring the following areas to help us learn how we can open up brownfield site data and make it easier to use:
An index of brownfield site registers
Questions we’re asking
Brownfield site data for local authorities can be difficult to locate and there’s no public register where all local authorities’ data can be viewed in one place. Would creating a national index of all brownfield data be of value to local authorities and other interested members of the community?
What we tested
What we learned
We made a number of useful observations while building the collection, including that:
- planning authorities often failed to provide a direct link to the data (for example linking to a policy page instead)
- when some registers were updated their URLs changed (URLs were not static)
- registers were often published in formats other than CSV (such as Microsoft Excel files)
- registers often contained gaps or errors
Guidance on updating your brownfield site data
Questions we’re asking
Would guidance help local authorities publish their brownfield data to a standard format, and minimise errors?
What we will test
We’re currently creating guidance on publishing brownfield site data. We will test this guidance with users from local planning authorities and continue to improve it.
Brownfield site data validator
Questions we’re asking
Often the person in the local authority updating the brownfield site data has little or no spare time, has varied responsibilities and is not familiar with the brownfield data format. As a result, errors are common in the published data. Would offering a simple tool for validating a local authorities’ data improve this?
What we will test
We built and tested an early version of a validator and based on what we learnt we are now creating a new collector tool. This will check local planning authorities’ brownfield site data and display the results of all local authorities’ data.
A way of fixing errors
Questions we’re asking
Many of the errors we identified in published brownfield data were common mistakes, such as switching GeoX and GeoY coordinates, or omitting empty rows in the data. Would offering to automatically fix common errors after validating the data be useful to local authorities and improve the quality of the data?
What we will test
- a validation tool for brownfield sites
What we’ve learned
We spoke with people from local authorities who are responsible for publishing the data. Often they were not technically trained or experienced with working with data. We tested an old version of the validator with some of these users, many of whom were able to spot and correct the data errors. We may work on building a way of automatically correcting errors into the new validator.
Upcoming areas of investigation
We plan to explore the following by prototyping tools and by testing and consulting with people involved with brownfield sites, and responding to your feedback.
We will regularly add updates to the following issues on GitHub:
Timeline
We expored ways of simplifying the format, based on the collection of 2018 register.
We made a prototype map of the data collected so far.
We began work on a nightly collection process, starting with the brownfield sites collector.
15 June 2019
We met again with Campaign to Protect Rural England (CPRE) to further understand how they’re using brownfield data and how this might connect to other data sets. We also spoke about our ideas to make it easier for local authorities to collect and publish their data.
June 2019
We’ve been analysing the existing brownfield data to explore whether we can propose a simplified data standard that’ll be easier for local authorities to publish against. As a part of this work we’ve also been looking at what has changed since we last looked at the published registers.
4 April 2019
We met with CPRE to understand more about how they collected the brownfield data, the challenges they faced, and how they used the data.
March 2019
The CPRE published the 2019 State of Brownfield annual report. In the report they highlighted some of the challenges they faced whilst collecting brownfield data.
Summer 2018
We built a register of all the brownfield registers and prototyped a tool to validate the data.