Solar PV installations and planning requirements for non-domestic buildings

News – Monday, March 6th, 2017

Camden has the ambitious target of 80% reduction in borough-wide carbon emissions by 2050. Non-domestic buildings in Camden account for 65% of the total borough territorial emissions [reference: Green Action for Change, Camden’s Environmental Sustainability Plan (2011-2020)]. Most of the buildings we have today will still be around in 2050: new buildings only account for about 1% of the building stock each year. This means that more needs to be done to reduce carbon emissions within our existing building stock.

Generating renewable energy at a local scale is one of the ways that we can reduce carbon emissions, and many businesses are seeing the benefits of generating their own energy onsite. Solar PV is a good renewable energy technology that can usually be easily integrated onto existing buildings and generally pays for itself within 9-11 years (the higher rate Feed in Tariff may also reduce this payback period).

Camden has a rich architectural heritage with many special places and buildings, over 5,600 of which are nationally listed for their special historical or architectural interest and over 400 of which are locally listed. Camden also has 39 Conservation Areas, covering much of the borough, recognised for their special architectural or historic interest and their character and appearance. So it’s important that any renewable installations take this into consideration.

So how do businesses go about installing solar PV on their premises? What are the planning constraints? When is planning permission required and when is it not? What do we need to consider when installing solar PV on listed buildings? This blog aims to answer some of these questions and will hopefully provide some basic guidance on navigating the planning system when installing solar PV.

Do I need planning permission to install solar PV?

Building owners are allowed to undertake certain types of work on their properties without needing to apply for planning permission: these are called “permitted development rights”. This means that certain types of developments are lawful without the need to apply to the local planning authority for planning permission. Installation of microgeneration (defined as up to 50kW) solar PV is allowed under permitted development rights, subject to certain restrictions including, but not limited to:

  1. Article 4 Direction: Article 4 Direction may have removed permitted development rights meaning that you will have to submit a planning application for solar PV installation. A list of areas within Camden affected by the Article 4 Direction is available here.
  2. Listed building status: Listed Building Consent is needed for any works that may change the appearance or disturb the historical materials of a listed building, this includes installing solar panels. In most situations, you will also need to apply for planning permission.
  1. Non-microgeneration installations: If the installation is 50kW or greater it may require Prior Approval from the local planning authority. This will take into consideration the design and appearance of the system and impact on neighbours.

Installation of solar PV is also not considered permitted development where:

  • Solar PV panels project more than 200mm from the wall surface or pitched roof slope.
  • Solar PV panels extend beyond one metre above the highest part of a flat roof (excluding any chimney).
  • The solar PV equipment mounted on a roof is less than one metre away from the external edge of the roof.
  • Solar PV equipment proposed on a wall will be within 1 metre of a junction of that wall with another wall or with the roof of the building.
  • Solar PV are proposed on the slope of the roof or wall fronting a highway if the building is located within Article 2(3) land (this includes conservation areas).
  • The solar panels are proposed to be installed on, or anywhere within the curtilage of, a listed building.
  • Solar PV is proposed on a site designated as a scheduled monument.
  • The total output of the system (including previously installed equipment) exceeds 1 MW.

[Please note: the above refers to Part 14 Class J Permitted Development for solar PV located on a building. If you want to install ‘standalone’ solar microgeneration equipment there are slightly different requirements detailed under Part 14 Class K].

If there is any uncertainty then, it is advisable to contact Camden’s Planning Advice and Information Service here. You should also seek professional advice from a registered installer.

My PV installation will be considered permitted development, what should I consider?

Good practice includes ensuring panels are oriented south and tilted 30 degrees where possible – this will give the best overall annual performance. However, in some situations this might not be practical or possible; therefore installations at any pitch and facing anywhere to the south of due east and due west are feasible. An overshadowing assessment should be undertaken to ensure placement of panels avoids areas affected by shading.

You should consider the layout and design of the panels and work with your installer to design a system that is both effective and visually attractive. In general: don’t try to fit too much on; make sure things line up properly, and consider the material of the existing roof and the panels. You may want to consider solar tiles which can replace roof slates/tiles (although bear in mind the contrast of the new material with the existing roof material if only installing a partial array) or an ‘in-roof’ system where the solar PV is flush with the existing roof. Solar PV can also be combined with a green roof as the vegetation provides thermal regulation benefits to the panels.  Furthermore, panels should be easily removed when no longer in use.

You will also need to consider any structural constraints of the roof in accommodating the additional load, the ability for the roofing materials to support the solar panels, and any Building Regulations requirements such as fire protection and weather proofing. Suppliers of systems will provide an assessment of the local conditions and select the appropriate fixing method, taking into account any effects of the wind. Consideration needs to be given to the potential presence of bats and birds nesting or roosting in older buildings. If they are using the building, equipment must be installed when they are not present, and maintenance must be planned to avoid disruption.

Your installer should be able to provide you with advice on the best solution and will ensure that you meet the relevant regulatory requirements. You should always ensure that any installer you appoint is a Microgeneration Certification Scheme (MCS) certified installer and that the equipment itself is MCS certified. MCS is a government supported, industry-led and nationally recognised quality assurance scheme. Early conversations with the prospective installer and a site visit will be beneficial as there might be some additional electrical work required for the connection or a need for a road closure to allow for crane access to install the equipment. It would also be beneficial to talk about maintenance and energy monitoring contracts at an early stage to ensure the maximum efficiency of the panels.

Any leaseholders will of course also need to gain the necessary permissions from the building owner before planning a solar PV installation.

Conservation Areas

About 70-80% of the borough consists of Conservation Areas. If your property is located within a Conservation Area then impacts on the character and appearance of the area should be taken into consideration when planning any solar PV installation. Similarly, if your property is locally listed then the impact on the building’s significance should be taken into consideration (see below).


  • Solar PV installations on buildings affected by the Article 4 Direction will require planning permission.
  • Solar PV proposed on the slope of the roof or wall fronting a highway if the building is located within article 2(3) land is not considered to be permitted development.

If there is any uncertainty then it is advisable to contact Camden’s Planning Advice and Information Service here.

Listed buildings

Listed buildings are not automatically prohibited from installing solar panels, although this is not permitted without first obtaining listed building consent.

The Council’s planning policies seek to ‘balance achieving higher environmental standards with protecting Camden’s unique built environment’ and ‘proposals that reduce the energy consumption of listed buildings will be welcomed provided that they do not cause harm to the special architectural and historic interest of the building or group’.  For listed buildings (and buildings within conservation areas) you need to know what the key issues are: whether it is the impact of the panels on the building fabric and/or the character and appearance of the building. You will need to demonstrate to the local authority that the works will not adversely impact the building or its character.

You will need to apply for Listed Building Consent and most likely you will also need to apply for Planning Permission, depending on the placement of the panels and the condition of the listed building. The whole process takes around eight weeks.

This will likely require you to submit the following information:

  • Heritage statement: although these will vary in the amount of detail according to the particular circumstance of the application, there are a number of fundamental details that must be included:
    • Details of the significance of the heritage asset (including photographs). This should include details of the character and architectural/historical interest of the associated property or structure and any significant design features of the building.
    • Principles and justification for the work being undertaken.
    • Impact of the proposals on the significance of the heritage asset and its setting (and adjacent listed buildings). Include any relevant photographs.
    • Details of any steps taken to avoid or minimise adverse impacts on the significance of the asset. This will include details of the impacts on strategic viewpoints, details of how the panels will be fixed to the roof, and details of the routes the associated service pipes will take and if these will impact the fabric or quality of the interiors.
    • An explanation of the sources considered and the expertise consulted in formulating the application.
  • Statement of need: this should demonstrate the benefits of the project to the community e.g. contributions to carbon reduction, fuel poverty alleviation, local employment, income generation, enabling future continued use of the building, etc.

You should work with and agree the approach with planning conservation officers and if appropriate seek pre-application advice. In your submission, you should seek to address any concerns which conservation officers may have. Most of the time the main concerns are:

  • Visual impact: how visible are the panels, and if they are visible what will they look like. You may have to ensure the panels are not visible from street level, meaning keeping the angle of projection as low as possible and setting the panels away from the parapet as much as possible. In some circumstances, you may have to be creative in your solar panel placement. 3D modelling can help to determine whether strategic views are impacted by the inclusion of solar panels, although it’s not always essential. Additionally, simple trigonometric calculations and diagrams can be submitted as supporting evidence. In the Swiss Cottage Library example below, officers positioned life-size cardboard cutouts of the solar panels on the roof and took photographs at street level to demonstrate that strategic views were not affected.
  • Impact on historic building fabric and level of reversibility: The panels will need to be fitted in a way that minimises any harm caused to the building fabric, and allows the panels to be easily removed. You will also need to consider any alterations required to feed the cables to the main electrical intake.

You should also include all relevant existing and proposed plans, sections and elevations as well as manufacturers details and details regarding fixing the equipment to the building, including schematic pipe route locations. All of which could be provided by the installer.

Case Study: Swiss Cottage Library.

Swiss Cottage Library is a Grade II listed building, designed by Basil Spence in 1962-64. One of the key design features of the building is the roof line (with its finely finished projecting fins) and views from street level. It was recently granted planning permission for a 49 kW solar PV array on the flat rooftop of the building. Installation is planned for springtime this year.

Officers worked with the planning authority to address potential heritage and conservation issues relating to the project, in particular, the views from street level. To mitigate potential impacts, the following measures are proposed:

  1. Panels are tilted 10 degrees, which although lower than the recommended 30 degrees, is sufficient to maintain self-cleaning properties. Additionally, there will be a maintenance contract put in place to include annual cleaning of the panels.
  2. The PV panels will be mounted onto the roof in the same way as the existing plant equipment, i.e. mounted on 10mm rubber pads on an A frame with a ballast. There will be no penetration through the roof, therefore minimising the impact on the building structure.
  3. Any cables will be fed through the existing riser to the main electrical intake located within the basement, meaning there will be no additional drilling.
  4. Panels are to be set back a minimum of 1meter from the roof parapet.
  5. The panels are west-east facing to maximise the coverage of the roof area and the size of the system.

A positive and proactive dialogue with planning officers was essential in progressing this project. Officers were able to demonstrate to conservation officers that the panels would not be visible from the identified strategic viewpoints. Because the final supplier was also engaged in the planning application process, they were able to discuss the layout and technical requirements, undertake necessary desktop analysis, and produce the necessary drawings.

If you have any questions or concerns, please get in touch with the planning department.

You can apply for listed building consent and planning permission through the Planning Portal website.

Author: Ana Lopez, Sustainability Officer, London Borough of Camden