Factors that restrict development

Geographic constraints - general

The relevance of site location

A potential development may be constrained in various different ways by its precise geographic location; for example:

  • its inclusion within a defined zone (for example, a conservation area);
  • its proximity to some physical influencing feature (for example, a river that is prone to flooding or a landfill site);
  • its proximity to some physical feature that may be affected by the development (for example, a nature reserve or an Ancient Monument);
  • the inclusion within the development site of a protected feature or structure (for example, a Listed Building or a TPO).

More generally, the nature of the site's immediate surroundings will always be a major factor determining what types of development can be allowed.

Some restrictions result from local policy, but the majority are the result of statutory controls.

Constraints data

The Council keeps and maintains data on all sites, zones and geographic features that can be relevant to planning. All potential developments considered (including all planning applications) are checked against this data. Various different geographic constraints are summarised below, although the coverage here is not necessarily exhaustive.


In many cases, various interested groups or statutory bodies need to be consulted before a development can take place. Specific consultees are associated with each type of constraint. These include government agencies, interest groups, learned bodies, statutory undertakers, parish councils and also various sections within the local authority.

Urban and historic conservation

If an area has a distinctive character that is due to the presence of existing historic structures and features, then it is important that any new development should not negatively affect this character and that its appearance does not have a strong impact. To help to avoid erosion of the historic environment, the following types of areas, structures and features are given statutory protection:

English Heritage is normally consulted on developments affecting these types of sites.

Separate permissions are sometimes required in addition to planning permission for some types of development.

Nature conservation and countryside

Designated sites within the natural environment are protected against destruction or gradual erosion. Types of sites include:

  • Sites of Nature Conservation Importance (SNCIs)
  • Local Nature Reserves (LNRs)
  • Sites of Special Scientific Interest (SSSIs)
  • Great Crested Newt Sites
  • Ancient Woodland
  • Hedgerows

Also, the presence of public rights of way (country footpaths and bridleways) within, or adjacent to, a development site may be an issue, particularly if access would need to be temporarily blocked during the construction phase.

Protected trees

All trees located within a conservation area are protected against tree pruning or felling without prior notification to the Local Planning Authority.

Local Authorities can issue a Tree Preservation Order (TPO) to a specific tree or group of trees. Such trees are protected against pruning or felling without permission.

Removal of permitted development rights

Permitted Development refers to small developments that can be carried out without the need to apply for permission. Permitted Development Rights may be removed for specifically defined areas (under "Article 3") so that permission would be required for various specified types of development that otherwise would not have needed permission. Similarly, rights can be removed (under "Article 4") for a particular conservation area.

In 2006, an Article 4 Direction was made for Northgate Conservation Area. No Article 3 Directions have ever been applied within the Darlington Borough.

Health and safety aspects

  • Flood risk: The Environment Agency has defined areas where risk of flooding is significant and for which it needs to be consulted on all proposed developments within these areas. A "flood risk assessment" needs to be provided by the applicant for such applications. For more details, see Flood Risk.
  • Industrial hazard sites: This includes sites where industrial chemicals are stored. The Health and Safety Executive provides a recommendation on whether a particular development is advisable near such sites. There are 4 of these sites within the borough: Transo gas holder in Valley Street, Broken Scar water treatment works, Hydro Polymers at Aycliffe Industrial Estate and Gately Moor Reservoir (near Bishopton).
  • High pressure gas pipes: There are several long sections of high pressure gas pipes within the Darlington Borough around which no building should take place for safety reasons. Immediately beyond these unsafe areas is a further zone for which Health and Safety Executive's [external link] advice must be sought before any new development can take place. Fortunately these areas are mostly on farmland and away from built-up areas. From a planning point of view, these are treated similarly to industrial hazard sites.
  • Contaminated areas and landfill sites: A number of sites within the borough are contaminated or unstable as a result of previous uses. While it is desirable that such sites which are otherwise suitable for development are brought back into productive use, it is also essential that the health and well-being of people working on the site or the end-users of any development are not put at risk. Where a site is known to have contamination or landfill related problems, the applicant will be required to investigate conditions on the site, and submit a report on the investigation methods, results, and the measures needed to enable development to be carried out safely. Investigations should include consideration of the need to protect the quality and quantity of groundwater supplies. For details of the Council's policy and strategy on this subject, see contaminated land.

Local Development Plan

The adopted Local Development Plan is usually the first consideration when judging whether a proposed development is suitable. It sets out in detail the Council's policies for the control of development, with specific sets of policies applying to each defined zone. The Plan also puts forward proposals for the development and use of land, including allocating some sites for specific purposes.


Good design is a fundamental requirement for all new development and the design should always be appropriate for the surroundings. The physical character of a setting will influence the possible types of design, scale, massing, form and materials that can be used.

The inclusion of a Design and Access Statement is now a requirement for some types of application.


  • Developments affecting air traffic: Durham Tees Valley Airport is always consulted on any proposed developments in the immediate vicinity of the airport. There is similar consultation for tall developments above a specific height further away from the airport.
  • Large-scale landscaping: Durham Tees Valley Airport is also consulted on certain large-scale developments within a 13km radius of the airport. Types of development include: mining, quarrying, tree planting, nature reserves, reservoirs, aviation, sewage works and refuse tips.
  • Mineral deposit areas: There are sites of mineral deposits of economic importance within the borough, including sand, gravel and coal. The Council endeavours to safeguard such deposits for the future. Any developments that may compromise this would be regarded unfavourably.

Factors not applicable to Darlington

Factors that do not apply within the Darlington Borough are summarised as follows:

  • anything relating to the coast or national parks will not be relevant
  • there are no designated Areas of Outstanding Beauty in the Darlington Borough
  • there are no licensed explosive sites or licensed nuclear sites within (or near to) the Borough
  • there are no areas where Permitted Development Rights have been removed under Article 3