When submitting a planning application in the UK, one critical aspect often overlooked is access to natural light. A Daylight and Sunlight Assessment ensures that both your proposed development and surrounding properties receive sufficient light, in line with planning policy and BRE guidelines. Without this, applications are at risk of delay, objection, or even refusal.
Understanding how and when to commission a daylight and sunlight assessment can make a significant difference to your project’s success.
What Is a Daylight and Sunlight Assessment?
A daylight and sunlight assessment evaluates the potential impact of a new development on the levels of natural light received by neighbouring buildings, and sometimes the new buildings themselves. It assesses this using established criteria from the Building Research Establishment (BRE) Guide: Site Layout Planning for Daylight and Sunlight – A Guide to Good Practice.
These assessments are particularly important in dense urban areas, where new buildings could overshadow existing properties or reduce daylight for neighbouring residents.
When Is a Daylight and Sunlight Assessment Required?
Planning authorities may request a daylight and sunlight assessment if your proposal:
• Includes multi-storey or high-density development
• Is located close to existing residential properties
• Could overshadow gardens or public spaces
• Involves changes to window placement or building layout
• Alters the skyline in a conservation area or dense urban zone
The goal is to maintain good living conditions for current and future occupants — and your assessment demonstrates you’ve considered this from the start.
Why Are Daylight and Sunlight Assessments Important?
- Meet Planning Policy and BRE Guidelines
Most UK councils reference the BRE’s guidance as a benchmark. An assessment ensures your design complies with these standards and addresses any light-related concerns proactively. - Avoid Planning Delays or Rejections
Lack of a daylight and sunlight assessment can delay the validation of your planning application. Worse still, planning officers may raise objections late in the process — requiring redesigns or re-submissions. - Protect Neighbouring Amenity
Overshadowing and reduced daylight can trigger complaints and formal objections from neighbouring residents. A clear, technical assessment can help address these issues early and recommend effective mitigation. - Support Design and Layout Decisions
Your assessment can guide architects and planners in shaping the massing, orientation, and window layout of a new development — improving the overall quality of the built environment. - Strengthen Your Planning Submission
Submitting a professional daylight and sunlight assessment from a trusted consultant adds weight to your application and shows local authorities that you are meeting your environmental responsibilities.
What’s Included in a Hawkins Environmental Daylight and Sunlight Assessment?
At Hawkins Environmental, we provide precise, planning-focused reports based on the latest BRE guidance and local authority expectations. Our assessments typically include:
• 3D modelling of the proposed and surrounding buildings
• VSC (Vertical Sky Component) and APSH (Annual Probable Sunlight Hours) analysis
• Detailed shadow studies and visual impact assessments
• Assessment of daylight to internal spaces
• Advice on design alterations to improve compliance
• A clear, concise summary for planners
Our assessments are fast, clear, and tailored to each project — making your application stronger and more likely to succeed.
A robust Daylight and Sunlight Assessment helps you avoid objections, navigate the planning process more smoothly, and ensure your development delivers a high standard of living for future occupants.
Need help with your application? Get in touch with Hawkins Environmental today.
Contact Hawkins Environmental
• Phone: 01256 522332
• Email: enquiry@hawkinsenvironmental.co.uk
Frequently Asked Questions
Q1: Is a daylight and sunlight assessment always required for planning?
A1: No, but it is often requested for developments in urban or built-up areas, or where there’s a risk of overshadowing. If your proposal is likely to impact light for neighbouring properties, it’s best to commission one early.
Q2: How long does it take to complete a daylight and sunlight assessment?
A2: Most assessments are completed within 5–7 working days, depending on project complexity and access to architectural drawings or 3D models.
Q3: What happens if the assessment shows a loss of light?
A3: The report will include recommendations to mitigate the impact, such as adjusting building height, repositioning windows, or redesigning massing to improve light access and avoid planning refusal.