Using GIS to Strengthen the Evidence Base in Planning

Geographic Information Systems (GIS) have become a core part of how planning evidence is prepared, understood, and communicated. With councils facing a range of  time and resourcing pressures, GIS tools provide clarity and efficiency at every stage of plan-making. At DAC Planning, we use GIS not as an add-on, but as a way of turning complex datasets into accessible insights that can support decision-makers, professionals and communities alike. 

How we use GIS in our work 

Our team works with local authorities across England to produce map and spatial data analysis that underpins Local Plans, Neighbourhood Plans and an array of technical work including Infrastructure Delivery Plans (IDP) and Green Belt Reviews.   

For example, in the recently published Castle Point Green Belt Assessment (July 2025) our GIS analysis helped to assess how different parcels of land perform against Green Belt purposes. Rather than just pages of text, the maps tried to tell the story visually — making the evidence clearer, more transparent, and easier to use in decision-making. 

Figure 1: Recommendations for  sub-area assessments against Green Belt purposes 

Source: Figure 15 of the Castle Point Green Belt Assessment (July 2025) 

The map in Figure 1 brings together the conclusions of the detailed sub-area assessments. Each parcel of land was tested against the Green Belt purposes a), b) and c) before being mapped to show where land performed strongly or weakly. Presenting the results in this way helps to communicate the final recommendations in a clear and visual way.  

As well as using GIS to visualise assessment data, we also apply digital mapping solutions to large Microsoft Excel datasets (think thousands of property records) with the aim of representing the data as heatmaps or choropleth maps. Instead of scanning endless rows of figures, you see a shaded map that help to identify patterns and trends instantly.  We are also able to undertake overlay analysis combining datasets such as flood risk zones, heritage assets, environmental constraint mapping. Our maps are embedded into the key planning documents, whether that’s a Green Belt Assessment, an Infrastructure Delivery Plan, a Local Plan or even a CIL charging schedule. By being part of the document itself, the maps help explain the evidence and makes it easier for people to follow the reasoning behind decisions. and also produce interactive consultation maps.  

Each project is different, but the common thread is making complex evidence more transparent, and easier for stakeholders and communities to understand. 

Why this matters 

The government has been clear that planning needs to go digital. The Digital Planning Programme launched by MHCLG is all about creating data-driven, transparent processes, and efficiency. This sits alongside initiatives like Planning Data Platform which is developing national standards and tools to make planning data more open, consistent and usable. At the same time, open data (such as GIS layers from Ordnance Survey, Natural England, Historic England, Magic, Defra, ONS, etc) is becoming more widely available, creating opportunities for councils to use richer evidence bases. But for this to work, data needs to be standardised: structured and formatted consistently based on the area of interest. Without this, digitalisation risks creating new silos rather than solutions.  

Looking ahead 

As planning reforms continue, GIS will only grow in importance. Digital planning is no longer optional, with reforms introducing new Spatial Development Strategies (SDSs), and the proposed 30-month plan making cycle, digital tools are central to delivering robust and timely plans.  

But technology alone isn’t the answer. Digital tools only add value if they’re used with purpose. The real starting point is to define the challenge by knowing what we already have and what we are missing. This will give a clear picture on what problem are we trying to solve, and what evidence is needed to address it.  Without that clarity, outputs risk being generic or even misleading. The quality and relevance of the data input will always shape the value and quality of the results. 

That’s where we see our role. At DAC Planning, we don’t just produce maps- we try to understand your need and help you identify the right datasets, and then use geospatial analysis to generate clear, problem-focused evidence. We are committed to investing in our geospatial capability not only to meet the government’s digital agenda, but to ensure our outputs are not just technically robust but valuable to our clients and the communities they serve.  

If your authority is looking to strengthen its evidence base or navigate the transition to digital planning in terms of understanding the data, updating the data system, assistance with handling GIS data sets or even defining the problem - we’d be happy to help.  

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How we can help

DAC Planning has extensive experience and understanding of plan making, and provides dedicated support to local authorities nationally.

For a discussion on how we can assist you, please get in touch with the team:

admin@dacplanning.com / 01206 688103

This information is for general informative purposes only. Whilst every effort has been made to ensure its accuracy, DAC Planning accepts no liability whatsoever for any direct or consequential loss arising from its use.