The conundrum of electricity pylons and development

Electricity pylons and overhead power lines are a common sight snaking across the length and breadth of the country, but should they be considered a barrier to development on the land they pass over? If developers or landowners wish to develop land crossed by overhead power lines or close to electricity pylons, then there are matters which need to be taken into account, particularly in relation to the design and location of the development – but proximity is not a bar. In this article we focus on the considerations required for development in the vicinity of electricity pylons and overhead lines and how these are reflected in practice, in planning applications, and planning appeals. The statutory background  Surprisingly, there is no specific statutory regime that developers need to comply with when developing land crossed by overhead power lines or containing pylons or towers, other than maintaining prescribed safety clearances. As with all new development, applications will need to comply with planning policy and legislative requirements, but they should also take into account National Grid’s Design Guidelines (2003) (the design guidelines). The design guidelines National Grid Electricity Transmission plc (NGET) is the transmission licence holder for England and Wales, carrying electricity across the country on large overhead power lines. It is under an obligation to develop and maintain the nation’s electricity transmission system. However, generally, NGET does not own the land crossed by its overhead lines. NGET has developed practical advice in the form of the design guidelines to ensure high-quality development on land shared with existing transmission routes and to provide appropriate guidance to developers when designing any new development. This allows more development sites to be brought forward through the planning process on land that would otherwise be constrained by the presence of overhead lines. By incorporating the design principles into plans for new development at an early stage, developers can successfully mitigate the impact of overhead lines. Two of the main principles running through the design guidelines are (a) that the nature and extent of the impact caused by an overhead line varies between different sites and so one solution does not fit all; and (b) the closer to the overhead line that the development is built, the design and attention to detail must increase. The design guidelines provide useful guidance for developers to consider when developing land crossed by overhead lines or pylons: Development intensity and public realm. Designing residential development so that it is more enclosed and compact (and siting the development closer to high-voltage overhead lines) can allow the development to obscure views of pylons and can diminish their visual impact. Likewise, altering the alignment of streets or curving them by small degrees can help offset views of pylons. Utilising land. Where development is proposed on a site crossed by an overhead line, there are good operational and amenity reasons for not positioning built development directly beneath, primarily disturbance during maintenance. However, the design guidelines set out the types of land use that may be appropriate beneath overhead lines. Examples include public open space, allotments and community orchards. Screening. It is important that the development is designed with layers of strategic screening such as planting, to reduce the visual impact, improve air quality and reduce noise. However, the safety clearances will always need to be complied with. Feasibility of relocating pylons and/or overhead lines NGET is usually resistant to applications to divert or underground OHLs to facilitate new development, and instead encourages developers to reach out and communicate with it in order to minimise the visual impact of pylons and overhead lines, through sensible urban design. Diversion is usually ibbbmpractical because of: The prohibitive cost of moving existing overhead lines. In the event that it is possible to move an overhead line, the costs will need to be borne by the developer, often making the development unviable; The technical complexity of moving the line. A number of NGET’s electricity lines have been given development consent by the secretary of state (since 2008) or installed using compulsory purchase powers. Any rerouting could require new consents and landowner agreements which can be difficult to obtain; The impact on the electricity system during works. Where alterations are made to the transmission system, electricity will need to be routed in a different way to ensure that power is provided to all parts of the country continuously. Maintaining the supply during works can therefore be difficult and costly to undertake; and The electricity transmission network, which is a fundamental and permanent part of the UK’s national infrastructure and should be treated as such. Therefore assets should be retained in situ unless exceptional circumstances apply. There are limited opportunities for outages to allow for alterations to be made to the system, and any outages are usually scheduled months in advance. Statutory safety clearances Uninsulated high-voltage power lines are incredibly dangerous to approach, and direct contact would likely be fatal. Therefore, it is essential for developers to comply with statutory safety clearances when developing close to overhead lines. The clearances are set out at Regulation 17 and Schedule 2 of the Electricity Safety, Quality and Continuity Regulations 2002. The majority of National Grid’s power lines run at voltages of 275kV and 400kV, requiring a 7m and a 7.3m minimum clearance respectively. This should be factored into development close to power lines, including proposed building height and the positioning of any street lighting or trees. It may be surprising, however, that this is the only statutory constraint on development around pylons and power lines. In summary, early consultation with National Grid is essential to ensure that all parties are working together to promote the highest possible quality design, which takes account of the visual and environmental impacts of overhead lines and electricity pylons. Case studies There is a distinct lack of case law on development around electricity pylons, which may be due to the few legislative restrictions in place for developers when seeking to build around them. However, developers must still comply with the planning regime and, as such, issues arising from proximity to power infrastructure are material considerations in decision making, leading to a number of appeals. 1. Effect on amenity Planning permission for the construction of a new dwelling was rejected by Shropshire Council on the basis that the presence of two large pylons at the site between which the proposed dwelling would be sited would be inappropriate, as it would cause harm to the quality of life experienced by the occupiers of the new dwelling (reference number 14/01138/OUT). During the course of the application, the applicant corresponded with Western Power Distribution, which was responsible for the pylons at the site. It confirmed there were no safety concerns and the presence of the lines should not affect the planning application. However, the council held that there were significant visual and physical impacts of siting the dwelling so close to the two pylons, and subsequently refused the planning application. The applicant appealed the council’s decision but the Planning Inspectorate agreed with the council and dismissed the appeal (appeal reference APP/L3245/W/15/3121604). This was on the basis that the development would harm the quality of life of the occupants by reason of the overbearing visual impact of the pylons. Although the Planning Inspectorate confirmed that the proposal would comply with the relevant electricity utility safety requirements, this did not weigh significantly in favour of the proposal because it was a matter of technical compliance. This demonstrates that the visual and physical impact of the pylons is a material consideration, and just because the presence of the lines is safe doesn’t mean that the other impacts should be disregarded in the planning process. 2. Offsetting costs for removal Planning permission was granted by Monmouthshire Council for 250 homes, including the removal of four electricity pylons (two located on the site and two on adjacent land), the installation of a single new terminal tower, and the undergrounding of the electricity cables (appeal reference APP/L3245/W/15/3121604). Given that the landowner or developer would need to pay for the removal of the OHL, the new tower and the undergrounding, the affordable housing provision on site was reduced from 35% to 19.6%, and this was accepted by the council on the basis of viability. The associated planning agreement also imposed an obligation that the landowner procures an agreement for the removal of the electricity pylons prior to commencement of development. If National Grid is agreeable to the removal and undergrounding of lines, the costs should be included in any viability assessment for the development as a whole to reduce the amount of other financial obligations required. Although Monmouthshire’s decision is not binding on other local authorities, it does demonstrate a willingness to adopt a pragmatic approach to delivery of housing. Sophie Stewart is a partner, Alexandra Jones is a solicitor and David Harrison is a trainee solicitor specialising in planning and environmental law at Brabners LLP