At Roberts Environmental Limited we are often approached by clients who are looking to develop Greenfield land. Whether needing to satisfy a planning condition or looking for additional information to inform development plans, one of the assessments we advise to carry out is an Agricultural Land Classification (ALC).

What is an Agricultural Land Classification?

The ALC system provides a method for assessing the quality of undeveloped / farmland in England and Wales and classifies land into the following 6 Grades:

• Grade 1 - Excellent
• Grade 2 - Very good
• Grade 3 - Good to Moderate (Subgrade 3a -Good, Subgrade 3b -Moderate)
• Grade 4 - Poor
• Grade 5 - Very poor

ALC and the National Planning Policy Framework (NPPF)

The Best and Most Versatile (BMV) agricultural land is defined as land which falls in ALC grades 1 to 3a. The NPPF and Planning Policy Wales, The Town and Country Planning (Development Management Procedure) Order, 2010 have measures in place to protect BMV land under planning policy. The use of ALC investigations means that developers and Local Authorities can fulfil the policies outlined within the NPPF. There is ALC data available for the whole of England and Wales contained within the Provisional ALC Mapping at 1:250,000 scale and the Online Mapping which are both publicly available. However, these large-scale maps have a number of limitations, including:

1. They cannot be used to identify the ALC grade at the field level (see Figure 1). This mapping was generally determined by consulting existing soil maps to formulate the ALC. This small scale mapping does not identify the variations which can occur across a proposed development site and may affect the ALC grade;
2. Many of the surveys were undertaken prior to the introduction of the ALC Grade 3a/3b subdivision in 1984. As such, the boundary between land which is classified as BMV (ALC Grade 3a) and non-BMV (ALC Grade 3b) is not available at 1:250,000 scale – this is notably crucial when considering a site for planning.

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Benefits of Undertaking an ALC on Your Site

A detailed ALC provides mapping at field scale for your site. The process involves both desk-based research and in-field sampling, logging and analysis of the soil to assess which factors influence the quality of your land.

Results are provided in a concise report along with a map showing the boundaries of all land grades on site. This information can provide a number of benefits, including;

Improving Chances of Gaining Planning Permission

Since the implementation of the previously mentioned planning policies, ALC surveys are largely required to satisfy planning conditions, ensuring BMV land is preserved and allowing non-BMV land to be developed.  

If you commission an ALC survey at an early stage, the information can be used to provide advice on the feasibility of the proposed development and best way to proceed.

In addition, informed decisions with regards to the layout of a development can be made. Liaison with developers and planners following an ALC survey can maximise the amount of non-BMV land which is to be developed, allowing any BMV land to potentially be incorporated into final designs and aid in the developer’s obligation to provide green space..

The key point is that by ensuring the development of lower quality (non-BMV) land, you will be able to better meet the requirements of planning policy, potentially making it easier to obtain planning approval.

Saving Time and Money

An ALC survey provides information which can be used to formulate a Soil Management Plan (SMP) within the working strategy for a construction site. These are a common condition of planning permissions when developing Green field sites, driven by longstanding Government initiatives such as:

Safeguarding our Soils: A Strategy for England

Without an SMP, incorrect soil handling during construction can result in damage, through soil sealing, compaction or pollution which makes the soil unsuitable for reuse within the development.

The remediation of impacted site-won soil or the need to import suitable soil can cause subsequent delays to the progression of a development. In addition, when ALC surveys have been used to inform correct soil handling, money can be saved, and sustainability increased when removing the need to import soil to site or export it as waste.

It's of note that ALC surveys can be conducted in conjunction with other Site Investigation techniques, further reducing costs and the time needed for in-field works.