Planning assessments

Services focussed on quantifying potential impacts from a range of environmental factors associated with new development

Service Catalogue

Herrington Consulting is an environmental consultancy specialising in flood risk management and light assessments. With 20 years of experience in the industry, we have provided advice to over 3000 clients, ranging from individual homeowners to master planners.

For all our services and information on our sister company EPS, please see our brochure.

01Flood Risk Management

Our Water Team specialists can assist on varying flood risk matters, providing site-specific advice to your development. We recognise the importance of minimising and managing the risk of flooding to your site, ensuring that both users of the site are safe, and the risk of flooding is not increased to the surrounding area.

Whether it is to inform your development potential, support a planning application or assist Local Authorities to undertake strategic planning, we have extensive experience in delivering complex technical reports for challenging projects, drawing on excellent numerical modelling capabilities and a diverse technical workforce.

Flood Risk Assessments

We provide flood risk assessments for all developments; ranging from reports to support householder or prior approval applications to large scale housing developments consisting of thousands of homes. We will appraise the risk of flooding from all sources taking due account of the impacts of climate change, utilising industry-standard software and the latest scientific data to provide the most accurate assessments possible. Where a risk is identified we will communicate any potential site constraints with regards to flood risk early on and, recommend appropriate flood mitigation measures to ensure that the flood risk can be managed.

Occasionally, our analysis may identify that there is no detailed flood information or available information is inaccurate and out of date. In such circumstances, we can expand our services to help include detailed numerical flood modelling. This can provide more flexibility in terms of scheme design and allows for different mitigation options to be tested.

The following services can either form part of our flood risk assessments or be provided as stand-alone service:

01

Flood Compensation Scheme

Where development is shown to have an adverse impact on the surrounding area due to floodwater displacement we can prepare a flood compensation scheme. The scheme will show how the offsite risk can be mitigated in accordance with the Environment Agency’s requirements. This can sometimes have a significant impact on the scheme design and therefore, it is imperative to consider flood compensation as early as possible within your design process.

02

Sequential Test Statement

A Sequential Test is typically required for sites which are shown to be at risk of flooding either now or in the future. The methodology applied for the Sequential Test can vary between Councils.

We have extensive experience in preparing Sequential Tests, having provided guidance to numerous Local Planning Authorities.

03

Flood Warning and Evacuation Plan

A Flood Warning and Evacuation Plan may be required if the development site is shown to be at high risk of flooding and safe access /refuge may not be achievable.

We can provide bespoke plans for your site to ensure that appropriate action is taken.

Feasibility Studies and Strategic Planning

Where mapping indicates that flood risk could be a constraint for development sites, we can undertake feasibility studies to determine the risk in more detail.  Our work will identify the key constraints to the development and clearly set out recommendations to overcome any hurdles.

Early engagement means that we can assist with maximising the potential of the site, whilst ensuring that future development will be strategically viable.

Working on garden villages has shown that flood risk forms part of a wider remit and is an integral part of the design process, helping to reduce further risk.

BREEAM

If you aim to achieve BREEAM accreditation for your building, we can assist with the preparation of reports to achieve the requirements set out under Pol03 in relation to Flood Risk Management and Surface Water Management Runoff. Depending on the type of standard, available credits vary and the team will be able to confirm how many credits can be obtained.

Appeals and Expert Witness Advice

We have successfully represented clients at planning appeals, hearings and public enquiries. We are also able to offer Expert Witness input in our areas of expertise so feel free to get in touch should you require assistance with any of these services.

Flood Risk Activity – Environmental Permit

For any works within close proximity to a main river or flood defence , you will be required to apply for an environmental permit. This is regulated by the Environment Agency in England and we can provide support throughout the entire application process. 

Water Framework Directive (WFD) Assessment

Where development could potentially impact on Water Framework Directive water bodies, an assessment of the impact may be required to show that the proposals do not result in a deterioration. We can undertake WFD Assessments, appraising the potential impacts of activities on site and outline mitigation measures to limit the impact.

02Drainage Engineering

Our drainage specialists have substantial experience of developing effective drainage solutions which are unique to each site. Whether it is an extension in London which requires surface water management, or a garden village where sustainable drainage (SuDS) forms part of the wider landscape strategy, our team understands the importance of well-engineered designs.

Whilst the focus tends to be on surface water management, wastewater management and Section 98 agreements can just be as important. Our experts are well versed in assisting on these matters and are happy to advise you on requirements.

Drainage Strategies

Drainage Strategies are required to manage water generated by developments. Our team of qualified drainage engineers have extensive experience in providing advice on how management of surface and foul water can be achieved. Following both national and local policy, we will work with the design team to ensure that industry best practice is followed, and the drainage strategy provides socio-economic benefits to your proposed scheme. Some sites can prove to be challenging, either due to steep land levels or limited methods for discharging water. Where this is the case, we will engage early on with relevant stakeholders to overcome any potential constraints and provide a suitable solution which works both for your project, whilst also satisfying local requirements.

01

Surface Water Management

New development has the potential to increase the risk of flooding to neighbouring sites and properties through increased surface water runoff. Our drainage engineers can assess both the existing and proposed site drainage to accurately quantify the runoff rates, flow pathways and the potential for infiltration at the site.

This assessment considers the practicality of incorporating Sustainable Drainage Systems (SuDS) into the scheme design, with the aim of reducing the risk of flooding by actively managing surface water runoff. We will work with the wider design team to ensure that any SuDS form an integral part of the wider landscape design and provide multi-functional benefits to the public.

02

Foul Water Management

Where new development is introduced, it may be necessary to demonstrate that there are means of disposing wastewater sustainably. Depending on the location of your site, this could either be via a connection to a public sewer subject to available capacity, or package treatment plants where no sewers are existent. Regardless of the location, we can assist in determining the best solution for your development and enter dialogue with necessary stakeholders to confirm acceptance.

03

Hydraulic Modelling

For developments such as minor and non-major, simple volume storage calculations for SuDS may be sufficient to demonstrate that surface water runoff can be managed sustainably. However, for most drainage strategies, a hydraulic model is required to estimate pre- and post-development discharge rates.

Herrington Consulting has a range of numerical models that assist in the development of Surface Water Management Strategies. These include FEH, ReFH and Causeway Flow+.

Where drainage flow paths have to be modelled, our in-house numerical flood modelling capabilities can assist in determining the impact of the development, taking account of existing features such as the drainage network.

Detailed Drainage Design

Once the concept of a drainage design has been approved by the Local Authorities as part of a planning application, a detailed drainage design will be required. The design typically requires liaison with manufacturers to take account for product-specific requirement. We can advise on appropriate products and prepare associated drawings which can be used for construction.

Section 98 and Section 106 Applications

For some development, a new connection to the public sewer may be required. A Section 98 requisition is required where a new public sewer is necessary, whereas a Section 106 agreement relates to a new connection to an existing public sewer. In both cases, we can assist with the formal request made to the sewerage undertaker.

Verification Reports

To ensure that the drainage design has been implemented and constructed as approved by the Local Authorities, a verification report may be conditioned. As part of the works, our specialists will collate evidence throughout the construction phase and present the information to the authorities in form of a report, with the aim of discharging any related condition.

Nutrient Neutrality Assessment

Where development is shown to result in a potential increase of nitrogen and phosphorus entering designated protected areas as defined by Natural England (NE), a Nutrient Neutrality Assessment will be required to demonstrate that any impact can be mitigated. We apply NE’s calculator and set out a mitigation strategy where possible.

Water Efficiency

With water scarcity becoming more prevalent in the future due to climate change, some Local Authorities may request evidence that proposed development can achieve water neutrality or a specific water consumption rate. We can assist in the preparation of required statements which set out efficiency measures and related calculations.

03Daylight and Sunlight

Herrington’s specialist Light team works on projects ranging from private builds and extensions, high rise developments and new build housing estates to conversions of basements and offices to residential use. We work with homeowners, architects, developers, retailers, local authorities, and planners. When you need help delivering your project on time with the optimal commercial outcomes whilst also meeting the required daylighting needs, our team of experts is always happy to talk you through and advice on the technical requirements needed for planning.

Designing for Light

We can assist with assessing the potential impact on natural light to neighbouring properties and the internal availability of natural light within new residential schemes, amongst other services. We have extensive experience in delivering complex technical reports for challenging projects using our expert 3D modelling capabilities. We can provide expert advice on scheme cutbacks for sensitive areas, maximum envelope studies to best utilise development sites and internal layout reconfigurations to meet minimum light standards in residential developments.

Daylight and Sunlight Assessment

Daylight and Sunlight Assessments can be used in a number of ways to improve the design of a scheme at all stages in the design process, for example scoping out development potential and identifying specific site constraints, or quantifying daylight and sunlight provision inside new dwellings.

01

Impact on Neighbours

In line with the recommended methodology set out within the BRE Guidelines (BR209 Third Edition 2022), the Vertical Sky Component (VSC), Daylight Distribution/ No Sky Line (NSL) and Annual Probable Sunlight Hours (APSH) tests are calculated. Our analysis is carried out using a 3D model of the existing, proposed and surrounding developments and simulations are undertaken for both the ‘existing’ and ‘proposed development, scenarios.

We can help with:

  • Maximum envelope/jelly mould studies
  • Cut backs to achieve BRE compliant schemes whilst maximising development within the site boundaries

02

Internal Provision of Light

In line with the recommended methodology set out within the BRE Guidelines, the Daylight Factor, Daylight Illuminance and Sunlight Exposure tests are carried out. Our analysis is carried our using a 3D model of the proposed and surrounding developments as well as closely located trees and other vegetation.

 

 

We are experts in providing advice to improve natural light to meet the recommended standards.

 

03

Overshadowing Studies

In addition to the BRE Sun on Ground test, we can provide Transient Overshadowing studies.

 

 

This study focuses on the shadows cast by new developments and are typically undertaken to assess the impact on amenity spaces such as gardens and public open spaces. The objective is to simulate the path and extent of shadows cast by new developments at hourly intervals at different times of year. The outputs are graphical rather than numerical and therefore require careful interpretation.

BREEAM

We can also undertake analysis to meet the BREEAM requirements for daylight provision within proposed new internal spaces such as residential dwellings, educational facilities, hotels, hospitals and student accommodation.

Up to two BREEAM credits are available for ‘Daylighting’ under Hea01. This aims to encourage good natural light is considered in building design, reducing the need to artificial light and improving visual comfort and well-being. 

European Standards – EN17037

The new European Standard EN 17037 is the first of its kind to deal exclusively with the design for, and provision of, daylight in buildings. This is important for the health and well-being of building users, but also helps to save energy by not relying on artificial lighting.

04External Light

For new developments there is now an opportunity for planning authorities to impose conditions related to external lighting, including curfew hours. In recognition of the growing need to assess and mitigate environmental impacts, Herrington Consulting can include Light Pollution/Light Impact Assessments as one of the Planning Assessment services we offer.

External Lighting Impact Assessments (ELIA)

There are many forms of light pollution and these are generically referred to as ‘obtrusive light’, which if not properly controlled can have physiological and ecological impacts. Since 2006, artificial light has been included on the list of possible Statutory Nuisances in England, Wales and Scotland and is also now referenced in both National and Local planning policy. We are able to undertake detailed External Lighting Impact Assessments that allow lighting schemes to be tested and potential adverse impacts identified and mitigated.

Why the need to assess?

An external light impact assessment is typically required for planning applications to ensure that the NPPF policy on light pollution from artificial lighting to local landscapes is met. Local Planning Authorities mainly follow the guidelines for external lighting installations set by the Institutions of Lighting Professionals (ILP) Guidance Note 1 ‘The Reduction of Obtrusive Light’ and ILP Guidance Note 08/23 – Bats and Artificial Lighting in the UK.

Planning considers:

  • The maximum lux for LED lights
  • The colour rendering indices of light sources below specified maximum values
  • The main beam angle of all lights within specified tolerances
  • Environmental Zones in the area surrounding the development (will determine their sensitivity to external light sources)

How we work

We promote a commercially balanced, phased approach to external light assessment with initial scoping assessments which may be used to address planning conditions in low sensitivity locations or to support a planning application, followed by more design / receptor specific assessment and lighting constraint modelling where an issue has been identified requiring a higher level of consideration.

We use numerical modelling techniques to analyse a range of lighting impacts or light pollution. This is a very general term which refers to the effect of over-lighting resulting from poorly designed lighting schemes and excessive levels of light. When external lighting installation requires impact assessment, be it in terms of glare or even potential impact on wildlife, our team of experts can help ensure your design is right.

We can help you with:

  • Light Trespass and Light Spill
  • Luminaire Intensity
  • Landscape Impacts
  • Assessment of potential impacts on foraging and commuting bats, carried out in line with the ILP Guidance Note 08/18 – Bats and artificial lighting in the UK

05Glint and Glare

What is a Solar Glint and Glare Assessment?

Glint and Glare Assessments are technical evaluations conducted to understand the potential impact of reflective surfaces, such as solar photovoltaic (PV) panels, on the surrounding environment. These assessments are often required to support planning permission, for ensuring that new developments are designed with consideration for their environmental and social impact. They are particularly important for developments that include solar PV installations or buildings with large glass surfaces and/or are located near infrastructure such as airports or railways.

Why the need to assess?

“Glint and glare” is the general term used to describe the reflection of sunlight from a reflective surface, typically one that is capable of producing specular solar reflections. Glint is defined as a momentary flash of bright light typically received by moving receptors or from moving reflectors, whilst glare is a continuous source of bright light, typically received by static receptors or from large reflective surfaces.

Solar glint and glare is a phenomenon caused by the concentrated source intensity of light and it can manifest in the built environment when the sun is reflected off infrastructure or building façades. In certain situations the scattering of light inside the eye can become visually disabling resulting in impaired vision. This impairment can present particular hazards to pilots, and drivers of vehicles and trains, and needs to be assessed.

The Solar Glint and Glare Assessment quantifies the potential for this disabling glare to present unacceptable risks in the vicinity of a building or infrastructure such as solar panels.

How we work

Herrington promotes a commercially balanced, phased approach to all types of lighting assessment with initial scoping assessments which may be used to address planning conditions in low sensitivity locations or to support a planning application, followed by more design / receptor specific assessment and constraint modelling where an issue has been identified requiring a higher level of consideration. Using industry proven modelling techniques and software to model for scenarios such as an aircraft on final approach or a train driver as they pass a signal, if a potential risk is identified, Herrington works with the team and the client on layout modifications (such as changes to panel tilt and elevation angle) which can often alleviate concerns and overcome objections. Our approach is to be comprehensive but cost effective and importantly, be team players for the wider project.