A development scheme may include a conservation area, a sensitive site or green belt land. Understanding all such planning constraints is vital when assessing a project.
Last updated: March 2026
Gill is our Editor, with a background that combines journalism with land and estate management. Gill is a farmer’s daughter, an associate member of the RICS and has an interest in all things to do with agriculture and the countryside. Her free time is spent on the tennis court, walking and improving her cooking skills.
Planning constraints like Green Belt, Conservation Areas and Sensitive Sites can make or break your application.
We explain what these designations mean for your development, from Change of Use categories to navigating local maps.
Whether you’re dealing with protected habitats or historic character, get the expert advice you need to clear the hurdles and secure your planning permission.
Planning constraints are restrictions that may affect development plans on a particular site. They can arise from environmental protections, historic designations, landscape policies, or specific planning regulations. Common planning designations include conservation areas and other environmentally sensitive locations.
Understanding what planning constraints are is important because they can influence whether development is possible, what type of development may be allowed and what permissions or assessments may be required.
A site may also be affected by multiple constraints in planning at once. For example, land might be located within a conservation area while also containing protected habitats or being subject to local planning policies.
In planning terms, change of use refers to altering the way a building or parcel of land is used. For example, converting an office building into residential apartments or changing agricultural buildings into commercial premises would be considered a change of use.
Understanding what a change of use is is important because certain changes require planning permission, while others may fall under permitted development rights. In some particular circumstances, a local planning authority may remove permitted development rights when an area of historic interest is involved.
In many cases, a change of use consent is required from the local planning authority before a building or site can be used for a different purpose.
Planning authorities will assess the potential impacts of the proposal, including traffic generation, noise, local infrastructure and the character of the surrounding area. Where a site is subject to additional planning constraints, further reports or assessments may be required.
Our consultants can advise whether a change of use consent is required and help prepare the necessary supporting information.
Planning legislation groups land and buildings into different change of use categories, known as Use Classes. These categories determine how properties can be used and when a change of use requires planning permission.
Examples of change of use categories include residential, commercial, industrial and community uses. Moving between certain categories may require formal consent, while others may be allowed without an application.
Understanding change of use categories is key when planning alterations to a building’s function, and professional advice may be required.
A conservation area is a designated location recognised for its special qualities, historic or architectural importance. Local planning authorities designate these areas to protect the character and appearance of buildings, village greens, individual trees, streetscapes and landscapes from inappropriate development.
Understanding what a conservation area is helps property owners recognise that additional planning considerations may apply. Development within a conservation area often requires careful design to ensure it preserves or enhances the area’s special character.
Where a property is located within a conservation area, certain works may require conservation area consent, planning permission or listed building consent.
This planning condition may apply to significant alterations to buildings, demolitions, tree works, or new development proposals. When it comes to decision-making, the planning authority will consider whether the proposed changes would significantly affect the historic character and cultural heritage of the area.
Obtaining conservation area consent ensures development respects the heritage significance of the location; this is especially relevant to historic towns and places with protected features or special architectural merit that are valued by the local community.
Local authorities publish a conservation area map showing the boundaries of designated areas. These maps allow property owners and developers to determine whether a site lies within a protected zone or a local green space designation.
A conservation area map can usually be accessed through a local authority’s planning portal or local plan documentation.
If you are unsure how to interpret a conservation area map, our team can help review your site and explain the implications for development.
This is a planning designation intended to prevent unrestricted sprawl from large built-up areas and protect local green space around towns and cities.
Understanding what green belt land is is important when assessing development potential. Public understanding of this policy means that development plans come under close scrutiny; development is strictly controlled and generally limited to certain types of use and the following purposes: agriculture, forestry, or infrastructure.
However, in some special circumstances, development proposals may still be considered if they meet specific policy tests.
Where development is proposed within the green belt, planning permission is typically required and must demonstrate that the proposal is appropriate under green belt policy.
This process is sometimes referred to as seeking green belt consent, where applicants must show that development would not harm the openness or purpose of the green belt.
Local planning authorities assess proposals carefully to ensure compliance with national and local policy. Planning consent may be allowed in exceptional circumstances.
A green belt map identifies the boundaries of green belt land within a planning authority’s jurisdiction. These maps help determine whether a site falls within protected countryside.
Consulting a green belt map is often one of the first steps in assessing the feasibility of a development proposal.
Our consultants can help review planning documents, including a local plan, the National Planning Policy Framework and interpret a green belt map to identify any development constraints affecting your site.
A sensitive site refers to land that has environmental, ecological, or landscape significance. These locations may include a local green space designation such as a site of special scientific interest, protected habitats, wildlife corridors, sites of outstanding natural beauty, national parks or sites with biodiversity value.
Specific planning policies apply: development proposals affecting special areas often require additional environmental assessments to ensure potential impacts from issues such as water pollution or hazardous substances are properly considered.
Understanding whether your site falls within special protection areas is an important step in the planning process.
Where development may affect a sensitive site, planning authorities may require additional approvals or supporting reports before granting permission.
Obtaining sensitive site consent may involve ecology surveys, habitat assessments, or other specialist studies, depending on the nature of the site.
Professional guidance can help ensure the appropriate evidence, such as proof of appropriate habitat creation or mitigation measures, is provided to support your application.
Local planning authorities and environmental bodies often provide a sensitive sites map showing areas with ecological or environmental designations.
Reviewing a sensitive site’s map can help identify whether a proposed development location falls within environmentally protected areas.
These maps are useful tools when assessing potential planning constraints and identifying what assessments may be required in the planning application process.
Navigating planning constraints and planning designations can be complex, particularly where multiple restrictions apply to a site. Understanding how these factors interact with local planning policies, such as urban regeneration and protection of open spaces, is key to progressing a development successfully.
Our consultants regularly provide guidance on constraints in planning, including advice on environmental designations and documents ranging from the neighbourhood plan to the National Planning Policy Framework, the Town and Country Planning Act and Natural England guidance. Through this process, they play an important role in advising on development limitations and planning strategies designed to enhance natural beauty in the local community.
Early professional planning advice from a planning consultant can help identify risks, avoid delays, satisfy planning conditions and improve the chances of a successful planning outcome.
If you have development plans and need advice on planning constraints, land designations, or development potential, Arbtech’s experienced team is here to help.
We can review your site, identify any planning designations and provide clear guidance on the permissions or assessments required.
Contact our helpful team today to discuss your project and find out how we can support your planning application.
Arbtech are your best asset when it comes to getting planning permission for your project. We cover the whole of the UK and we are waiting to get started on your project...
Get Your Free Quote