Strategic Housing Land Availability Assessment or SHLAA is a study that every local authority must undertake and provides an overview of the potential residential or employment-related development sites within each authority boundary.

What is the purpose of SHLAA?

The SHLAA study is a leading indicator of the authority's available land for development and can also identify if the council is behind its housing target. The SHLAA informs plan-making by doing three things:

• It identifies sites that have the potential for new housing
• It assesses how many homes they may accommodate
• It estimates when these sites, if suitable, are likely to be developed

‍However, the assessment does not in itself determine if a site should be allocated for development but provides information on the range of sites which are available to meet the local authority’s requirements.

How does SHLAA work?

There are several stages during the study, however, every council's process may differ slightly. 

In most cases, authorities will start with a "Call for Sites" which means anyone including land owners, developers or anyone can submit a site for them to review. This is just a long list of sites which could end up in the SHLAA study, but in no way guaranteed.

The council will then undergo an assessment process for all the sites in the long list and compare them to a threshold (specific to each authority). The threshold could include size, constraints, deliverability based on the local policy and others that each authority will take into account.

Once accepted into the shortlist, sites will be released to the public. Just because a site lands on this list does not mean it will be delivered, it is simply an acknowledgement from the authority that housing could be built on the site. The normal planning process will still apply and could be rejected.

SHLAA sites will be updated periodically by the council.

Example: How sites assessed in the London SHLAA

The London SHLAA includes an assessment of large sites (of 0.25 hectares and more in size) that is undertaken in partnership with boroughs and an assessment of capacity from small sites below this threshold. Large sites are identified from a range of sources, including:

• Sites included in previous SHLAAs
• Sites allocated for development in development plans
• Sites with planning permission
• Sites identified by land owners and other interested parties through a 'call for sites' exercise
• Sites identified through development capacity studies undertaken by the Greater London Authority (GLA)

What else does SHLAA data include?

In addition to a list of site names and addresses, SHLAA data also includes:

• Decision - indicating the status of the land parcel and includes criteria such as Deliverable, Developable, Not Developable 
• Units - illustrating how many units are achievable on the land
• Time frame - the timeframe for when these sites are likely to be available
• Decision reason - a summary of why the decision was reached

Why is SHLAA important for developers?

Property developers can leverage the insights from SHLAA to identify areas for development areas where housing development is likely to be approved - aligning their plans to meet the specific needs of the area to meet the specific demand for housing.

Where can you access SHLAA data?

Information about SHLAA sites is available online, as local authorities are required to publish their assessments and site lists. However, each council presents this data differently, ranging from PDFs to spreadsheets, making it difficult to navigate and search through the documents. Tools like Searchland, which organise and standardise the data, are incredibly useful for making this process easier and more user-friendly.

Want to learn more about a SHLAA-based land acquisition strategy? Read our blog.