1. Strategic Environmental Assessment

1.1 Introduction and scope of the SPD


Brighton & Hove City Council is preparing the Extensions & Alterations Supplementary Planning Document (SPD). This will predominantly provide guidance for residents wishing to extend or alter their residential dwelling, but will also provide guidance for the purposes of extending or altering premises in other uses and will be used to inform planning decisions undertaken on all types of extension or alteration. The SPD will cover the design and planning principles to be taken into consideration when planning an extension or alteration.


The National Planning Policy Framework describes SPDs as documents which add further detail to the policies in the development plan. They can be used to provide further guidance for development on specific sites, or on particular issues, such as design.


In 2013, BHCC adopted SPD12 Extensions and Alterations SPD. This new SPD will review and update SPD12 and bring guidance up to date with regards to national planning policy and permitted development rights.


The Local Development Plan for the city comprises City Plan Part 1 (2016) and saved policies from the Local Plan (2005). BHCC is currently developing City Plan Part 2, currently at draft stage, which will replace the Local Plan once adopted. Policies of relevance to the SPD include Local Plan policy QD14 Extensions and Alterations, City Plan Part 1 policy CP12 Urban Design, and City Plan Part 2 draft policy DM21 Extensions and Alterations all of which are of relevance to the SPD and provide the overall policy context.


The overarching aim of the SPD will be to supplement and support implementation of these policies and will provide design guidance for how extensions and alterations can meet existing policy requirements and in particular will provide guidance on:

  • Protection of local character, particularly in relation to scale, height and mass
  • Protection of amenity
  • Provide good practice examples

1.2 Legislative background


The Strategic Environmental Assessment (SEA) Directive (2001/42/EC) requires an environmental assessment to be carried out for certain plans or programmes. The SEA Directive has been transposed into UK law through the Environmental Assessment of Plans
and Programmes Regulations 2004 (hereafter referred to as “the Regulations”).


The Planning and Compulsory Purchase Act 2004 required Local Authorities to produce Sustainability Appraisals (SA) for all local development documents and it is considered best practice to incorporate requirements of the SEA Directive into an SA. Subsequently, the 2008 Planning Act removed the requirement to undertake an SA for a Supplementary Planning Document, but not the requirement for a SEA.


Government advice in Paragraph: 008 Reference ID: 11-008-20140306 of the Planning Practice Guidance (PPG) makes clear that SPDs do not require a sustainability appraisal but may in exceptional circumstances require SEA if they are likely to have  significant environmental effects that have not already been assessed during the preparation of the Local Plan.


In addition, the guidance states that an SEA is unlikely to be required where a SPD deals only with a small area at local level, unless it is considered that there are likely to be significant environmental effects.

1.3 SEA/SA undertaken – City Plan Part 1, SPD12 and draft City Plan Part 2


As part of the preparation of the City Plan Part 1, a combined SEA/SA was undertaken. This included assessments of all the policies contained within the City Plan including policy CP12 Urban Design. This found the impacts of policy CP12 to be positive and did not identify any adverse effects.


As part of the preparation of SPD12, a combined SEA/SA was undertaken. This found the impacts of the SPD to be positive, particularly for objectives relating to maintaining local distinctiveness and improving health. The SA did not identify any adverse effects.


As part of preparation of draft City Plan Part 2, a combined SEA/SA was undertaken. This included assessment of policy DM21 Extensions and Alterations. This found the impacts of the draft policy to be positive and did not identify any adverse effects.

1.4 SEA screening criteria and procedure


To assess whether SEA is required, Brighton & Hove City Council must undertake a screening assessment, based on a standard set of criteria as set out in the Regulations, to determine whether the SPD is likely to have significant environmental effects beyond those already identified within the SA/SEA of City Plan Part 1. The screening must then be subject to consultation with the three statutory bodies Historic England, Natural England and the Environment Agency.


Following consultation, the results of the screening process must be detailed in a publically available statement.

1.5 Screening


The following tables set out the criteria specified in Schedule 1 of the Regulations, and the response in relation to the SPD to help determine whether significant adverse effects are likely. The criteria look at both the characteristics of the SPD and also the effects of the SPD.

Characteristics of the SPD



The degree to which the SPD sets a framework for projects and other activities, either with regard to the location, nature, size and operating conditions or by allocating resources.


The SPD will supplement and elaborate on the principles set out in CP12 Urban Design (City Plan Part 1) and in draft policy DM21
Extensions and Alterations (draft City Plan Part 2). 

The SPD will not present any new policies, and its purpose is to provide greater clarity on how extensions and alterations can meet the requirements of policy. 

The City Plan Part 1 establishes the overarching planning framework and underwent full combined SA/SEA as part of its preparation. Saved Local Plan policies also form part of the overarching planning framework and provide development management policies, which will be replaced once the City Plan Part 2 is adopted. 

The SPD will therefore not set the framework for projects as it forms a lower tier of the existing planning framework.

Significant Adverse Effect?




The degree to which the SPD influences other plans including those in a hierarchy.


The guidance provided in the SPD will be supplementary to existing adopted policy and will provide clarity as to how development can meet the requirements of existing policy. 

The SPD forms the lower tier of the planning policy hierarchy and therefore does not influence other plans.

Significant Adverse Effect?




The relevance of the SPD for the integration of environmental considerations in particular with a view to promoting sustainable  development.


All planning documents must be in conformity with the NPPF and have an obligation to deliver sustainable development. The SPD will promote sustainable development through ensuring a high quality built environment and through supporting the health and amenity of residents and occupiers in and adjacent to the building extended.

Significant Adverse Effect?




Environmental problems relevant to the SPD.


Although the SPD will only be applicable to individual areas on a site-by-site basis, the SPD will be applicable city-wide and therefore some city-wide environmental problems could be of relevance as could be influenced by the design of buildings. However the guidance is unlikely to exacerbate problems and  could support improvements as described below.

Climate Change

Some of the impacts of climate change include increased extreme weather events, increased risk of flooding, higher temperatures and damage to ecosystems. SPD could support increasing resilience to climate change through support for biodiversity features, climate resilient materials and construction, as well as opportunities to reduce flooding. SPD could also support climate change mitigation through delivery of buildings which meet/exceed current building standards and therefore help reduce carbon emissions and water consumption. However, these issues likely to be outside the scope of the SPD.

Surface water flooding

Various degrees of flood risk exist across the city and development can increase the risk of flooding elsewhere. SPD may reduce the risk of surface water flooding by providing guidance on SUDS features which could be incorporated into extensions, e.g. soakaways, although this may be outside the scope of the SPD.

Green infrastructure/biodiversity

SPD may support net gains in biodiversity, e.g. through guidance on biodiversity that could be included within schemes, e.g. bat-boxes, green roofs etc, however this issue likely to be outside the scope of the SPD.

Any guidance the SPD provides on these issues will supplement and support that provided in existing policy, including CP8 Sustainable Buildings, CP10 Biodiversity and CP11 Flood Risk, as well as other adopted guidance.

Significant Adverse Effect?




The relevance of the SPD for the implementation of community legislation on the environment, like plans linked to waste or water protection.


The EU has adopted a range of legislation aimed at protecting the environment including:

  • EU Directive 2009/147/EC on the conservation of wild birds
  • EU Directive 1992/43/EEC on the conservation of habitats
  • EU Directive 2008/50/EC on ambient air quality and cleaner air
  • EU Directive 2002/49/EC on environmental noise
  • EU Directive 2008/98/EC waste framework directive
  • EU Directive 2000/60/EC) water framework directive
  • EU Directive 2007/60/EC assessment and management of flood risks.

The SPD will support implementation of and will be in compliance with the City Plan which has already taken account of the existing European and National legislative framework for environmental protection. It should therefore have a positive effect on compliance however this legislation has already been taken into account at a higher level.

Significant Adverse Effect?


Effects of the SPD



What are the probability, duration, frequency and reversibility of the effects of the SPD?


The SPD has potential to result in some positive environmental effects, as described under 1d.

The SPD also has potential to result in positive effects on the built environment, including areas with heritage designations, through ensuring the delivery of well-designed extensions and alterations.

The SPD also has potential to result in positive social effects, such as health and housing, as could result in improvements to housing that help it meet the needs of its residents, as well as ensuring extensions to all types of buildings do not have a detrimental effect on health and amenity of neighbouring occupiers, through reducing the risk of poor quality design.

Impacts are probable and some may be long-lived due to the“life” of any development and could therefore be considered permanent and irreversible. However, all effects are anticipated to be positive overall.

Significant Adverse Effect?




What is the cumulative nature of the effects of the SPD?


The SPD could have cumulative effects across the city, such as, through incremental changes arising from individual developments, however these effects are anticipated to be positive.

Significant Adverse Effect?




What is the transboundary nature of the effects of the SPD?


The effects of the SPD will be predominantly local in nature. There could be transboundary effects on adjacent authority areas, including the South Downs National Park, where an extension or alteration is located close to the boundary, however these should be positive in nature.

Significant Adverse Effect?




Are there any risks to human health or the environment, for example, due to  accidents?


No significant risks to human health or the environment are envisaged through implementation of the SPD.

Significant Adverse Effect?




What is the magnitude and spatial extent of the effects - for example, geographical area and size of population likely to be affected - of the SPD?


The SPD will be applicable to all extensions and alterations across the entire city therefore the magnitude and spatial extent of the SPD is considered to be large. However, extensions and alterations by nature generally only have a localised impact on the area or  population immediately adjacent, and as the SPD is promoting good design, this should prevent adverse impacts and ensure that this impact is positive.

Significant Adverse Effect?




Is the value and vulnerability of the area to which the SPD relates likely to be affected by the SPD due to:

  • Special natural characteristics or cultural heritage
  • Exceeded environmental quality standards or limit values
  • Intensive Land use


The SPD will be applicable city-wide.

Special natural characteristics

There is one European site within the city: Castle Hill SAC; there are two SSSIs: Castle Hill and Black Rock to Newhaven Cliffs;
there are 8 Local Nature Reserves; there are 86 Local Wildlife Sites (of which 36 lie wholly within the South Downs National
Park). Nature Conservation designations cover approximately 17% of the total area of Brighton & Hove. All of Brighton &
Hove falls within the Brighton & Lewes Downs Biosphere which aims to create a world-class environment, that is economically
successful and enjoyed by all, forever. 

There is a Marine Conservation Zone which extends from Brighton Marina to Beachy Head.

The SPD will be applicable to all extensions, including extensions that take place to premises located within or adjacent to sites with a nature conservation designation. As the main focus of the SPD is design related, the SPD is not  considered to have any impact on sites with nature conservation interest. The SPD will not cover issues of biodiversity, as these are addressed through other planning
guidance including the Nature Conservation in Development SPD.

Cultural heritage

The city has a rich historic environment, including around 3,400 individual listed buildings and structures, 34 conservation areas, 6 historic parks and gardens, 16 scheduled monuments and over 80 archaeological notification areas. One of the main aims of the SPD is to promote good design, and this will be applicable to all buildings including Listed Buildings and those within Conservation Areas. The SPD should therefore have positive effects on cultural heritage. The SPD will complement the adopted Architectural Features SPD.

Exceeded environmental standards 

Parts of the city are covered by an AQMA due to the exceedance of NO2. Some extensions and alterations may come forward within the AQMA. The SPD is aimed at promoting good design in extensions and alterations and is therefore considered unlikely to have any impact on air quality or the AQMA.

Intensive land use

The city of Brighton & Hove is heavily constrained and has a high need for new housing as well as other types of development. The City Plan Part 1 guides the development of significant new housing in the city and has a target of delivering 13,200 new homes in the area in the 2011-2030 period. The ability to extend and alter a dwelling can make it more suitable for its occupiers and this is unlikely to significantly intensify the land use. An extension could be used to create an additional self-contained dwelling, or could result on an additional floor on a block of flats, however again this is not considered to significantly intensify the land-use and will form one of the
considerations assessed during the planning application process.

The City Plan Part 1 also sets out the employment floorspace requirements for the 2011-2030 period. The ability to extend or alter commercial premises can help contribute towards meeting the need for additional employment floorspace. However, as with residential development, an extension or alteration is not considered to significantly intensify land-use and this will also form one of the considerations assessed during the planning application process.

Significant Adverse Effect?




Will the SPD have an effect on areas or landscapes, which have a recognised national, community or international protection status?


Part of the city includes land within the South Downs National Park (SDNP), however land within the SDNP is within its own planning area and therefore the SPD will not be of direct relevance to any extensions that come forward within the SDNP. The SPD will be of relevance to buildings that are located near or adjacent to the SDNP, however as the aim of the SPD is to promote good design, any indirect impacts on the SPD on the SDNP should be positive.

Significant Adverse Effect?


1.6 Initial conclusion prior to consultation


The impacts of the SPD are considered to be largely beneficial. The SPD is not setting new policy. It will supplement existing adopted and emerging policy that have already undergone through the SA/SEA process, for which the results were all beneficial, by providing further guidance.


It is considered that an SEA is not required for the Extensions and Alterations SPD as it is unlikely to result in any significant adverse effects.

1.7 Consultation and final determination


The results of the initial screening were made available to the three statutory bodies, Historic England, Natural England, and the environment Agency for a period of 28 days from the period 13th June 2019 to 12th July 2019 as required by the Regulation 9(2)(b) of the SEA Regulations.


Responses were received from all three statutory bodies. Statutory bodies either concurred with the conclusions of that the SPD was unlikely to give rise to significant environmental effects or had no comments to make.


Historic England considered the environmental effects concerned with cultural heritage to be minimal or negligible; the Environment Agency did not consider the plan would have significant effects in relation to issues covered by their remit; Natural England had no
comments to make.


Full consultation responses can be found in the Appendix.

2.0 Consideration of Habitats Regulation Assessment



Brighton & Hove City Council is required to consider whether its planning documents would have a significant adverse effect upon the integrity of internationally designated sites of nature conservation importance including ‘European sites’ which are designated
within the city of Brighton & Hove and the wider sub-region. This consideration is undertaken through a process known as a Habitats Regulations Assessment (HRA) which is a requirement of the Conservation of Habitats and Species Regulations (2010) (the Habitats


European sites provide important habitats for rare, endangered or vulnerable natural habitats and species of exceptional importance within the European Union. These sites consist of Special Areas of Conservation (SACs, designated under the EU Directive 92/43/EEC on the conservation of natural habitats and of fauna and flora - Habitats Directive) and Special Protection Areas (SPAs, designated under EU Directive 2009/147/EC on the conservation of wild birds - the Birds Directive).


Government policy, National Planning Policy Framework (NPPF, 2018) and Circular 06/05 (ODPM, 2005) requires that Ramsar sites (designated under the International Wetlands Convention, UNESCO, 1971) are treated as if they are fully designated European sites for the purposes of considering development proposals that may affect them.


The Habitats Regulations must be applied to all Local Development Documents (LDD) in England and Wales and aims to assess the potential effects of a land use plan against the conservation objectives of any European sites designated for their nature conservation


There are two stages of HRA; the screening which determines the likelihood of significant effects; and a full HRA which only has to be undertaken if the screening indicates that significant effects are likely or cannot be discounted at screening stage. Where a full HRA is
carried out, a plan may only be adopted after having ascertained that it will not have significant adverse effects on the integrity of the site concerned.


The City Plan Part 1, which is the overarching Development Plan Document for Brighton & Hove, was subject to a screening under the Habitats Regulations as part of its adoption. In addition, an updated HRA screening and subsequent Ashdown Forest Air Quality Assessment were undertaken in summer 2018 to reconsider the effects of implementing City Plan Part 1 alone and in combination with growth from other areas, as well as the effects of implementing City Plan Part 2. The purpose of this statement is therefore to reconsider the HRA screening assessments that have been undertaken for the City Plan Part 1 and City Plan Part 2 in relation to the Extensions and Alterations SPD.

Local European Sites


The Castle Hill SAC lies partly within the city’s boundary and partly within Lewes District Council’s boundary, although is located entirely within the South Downs National Park Authority Area. There are no Special Protection Areas or Ramsar sites within the city’s
boundary. There are also some European sites within 20km of the city including Lewes Downs SAC, Ashdown Forest SAC/SPA and Arun Valley SPA.


The Castle Hill SAC designation relates to the presence of chalk grassland and some rare and scarce species; the Lewes Down designation also relates to the presence of chalk grassland and some rare and scarce species; the Ashdown Forest designation is due to the largest single continuous blocks of lowland heath in the south east; and the Arun Valley designation is due to the wintering population of tundra swans.

Scope of the SPD


The purpose of the SPD is to provide guidance to property owners wishing to extend or alter an existing dwelling or premises in other uses. The guidance provided in the SPD will predominantly support the implementation of emerging City Plan Part 2 policy DM21
Extensions and Alterations. It is also of relevance to City Plan Part 1 policy CP12 Urban Design.


The SPD will provide guidance on how extensions and alterations can be designed to ensure that local character is protected, e.g. in relation to scale, height and mass, and how amenity of neighbours can be protected. It will provide good practice examples 

City Plan Part 1 Habitats Regulations Assessment screenings


A Habitats Regulations screening was undertaken in 2014 for the City Plan Part 1 (Proposed Modifications 2014), which relates to the adopted City Plan Part 1 (2016), and assessed the potential for impacts of all policies on the Castle Hill SAC. The screening also considered impacts on European sites outside the city which may also be potentially affected by development in Brighton & Hove including Lewes Downs SAC (6km from boundary), Ashdown Forest SAC & SPA (19.5km), and Arun Valley SPA (20km).


The screening included an initial assessment of the potential for environmental impacts resulting from each policy that needed to be considered by the HRA screening. The assessment concluded that there were no potential environmental impacts of relevance to
the HRA resulting from policy CP12 Urban Design.


The screening assessments also looked at the potential combined effects of all the policies within the City Plan, which could affect the integrity of European sites. These amounted to water abstraction, air pollution and recreational pressure.

Of these:

  • water abstraction was not considered to have a significant effect on any European site because there are no such sites which are vulnerable to water abstraction within the water catchment area of Brighton & Hove.
  • despite policies which promote travel choice and minimise air pollution, it is still possible that air pollution may worsen as a result of the City Plan Part 1. However localised air pollution of this nature would not have a significant effect on any European site.
  • recreational pressure on downland in the vicinity of Brighton & Hove may increase as a consequence of the City Plan Part 1. However only one of the European sites assessed is vulnerable to recreational pressure (Ashdown Forest). Studies elsewhere have shown that this site is far enough away from Brighton & Hove to safely conclude that there would be no significant recreational impact on it as a result of the City Plan Part 1, (with recreational pressure more likely to arise from developments within 7km of this SAC/SPA).


Therefore the HRA screening for the City Plan Part 1 discounted all possible significant impacts that would affect the designations of SACs or SPAs and therefore did not progress to a full Habitats Regulations Assessment.


Since this was undertaken, an updated Habitats Regulations screening has been undertaken in 2018 to reconsider the effects of the growth associated with the entire City Plan Part 1, in combination with growth anticipated from other areas, as well as effects arising from draft City Plan Part 2.

Page 42 of this assessment includes the assessment of relevant policy DM21 and concluded that there were no HRA implications from this policy. This screening assessment of the entire City Plan Part 2 discounted the likelihood of significant effects on Castle Hill, Lewes Downs, and Arun Valley European sites, however the assessment could not discount the likelihood of significant adverse effects of the entire Plan on the Ashdown Forest SAC/SPA. Therefore a detailed assessment of air quality impacts (Appropriate Assessment) on Ashdown Forest was undertaken.


The detailed assessment confirmed that growth resulting from City Plan Part 1 and City Plan Part 2, with an increased trajectory to 2032, would not result in adverse effects that would affect the integrity of the Ashdown Forest SAC/SPA, either alone or in combination with
growth from other area.


As the purpose of the Extensions and Alterations SPD is to provide further guidance on how the requirements of emerging City Plan Part 2 policy DM21 Extensions and Alterations could be implemented, the HRA screenings already undertaken are also of relevance to and apply to the SPD.



The Extensions and Alterations SPD is not considered to require further screening under the Habitats Regulations. The likely effects of the SPD have already been considered under the screening assessments undertaken for the City Plan Part 1 and City Plan Part 2 which
discounted the likelihood of significant adverse effects of all European sites within 20km of the city.



This statement was circulated to Natural England for information.

Appendix A Consultation Responses

To view the consultation responses, download the PDF version. You'll find this above the contents on this page.