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Designing for Light

Whilst there is currently no specific National Planning Policy relating to daylight and sunlight impacts, some planning authorities are taking these factors into account as material planning considerations.

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:

  • In scoping out development potential and identifying specific site constraints;
  • Assessing daylight and sunlight impacts to surrounding properties ;
  • Quantifying daylight and sunlight provision inside proposed dwellings;
  • Fulfilling the requirements for the Code for Sustainable Homes, BREEAM and the "Mayor of London's Supplementary Planning Guidance for Sustainable Design and Construction."

Through detailed numerical analysis Herrington Consulting can help to ensure that these criteria are achieved, and by calculating the illuminance incident on a surface within each room, it is possible to assess these values against the recommended lighting levels for different types of interior space, or specific visual tasks.



Impact on Neighbouring Buildings

The demand for space within towns and cities is increasing and often the solution is to build higher, more closely spaced buildings. Consequently, the need to assess the impact new development may have on the amount of sunlight and daylight neighbouring buildings receive is increasing.

Herrington Consulting are experienced in constructing detailed three dimensional models which can replicate the construction of new buildings within an existing location. Consequently, we are able to assess the impact that the new building(s) may have on the surrounding area and provide our clients with a quantitative assessment that can be used to aid design and support the planning application.

Please visit the Contact page and fill in your details to enable us to provide you with a free of charge, no obligation quotation. Alternatively, if you would like to discuss your project needs with on of our consultants we would be more than happy to help.



Overshadowing

Whilst there is currently no specific National Planning Policy relating to daylight and sunlight impacts, some planning authorities are taking these factors into account as material planning considerations. Additionally, there is often a requirement to assess whether local playgrounds, parks or gardens will suffer from overshadowing.

Herrington Consulting can provide overshadowing assessments that are in accordance with the BRE Guidelines for a range of developments and these assessments can include computer animations that track the shadow a building will cast.

Please visit the Contact page and fill in your details to enable us to provide you with a free of charge, no obligation quotation. Alternatively, if you would like to discuss your project needs with on of our consultants we would be more than happy to help.



FAQs

  1. What is daylight/sunlight analysis?

    The impact a new development will have on the amount of daylight/sunlight received by neighbouring properties is an issue that planning authorities are increasingly considering, particularly in urban environments.

    The Building Research Establishment guidance recommends 3 main tests which should be applied to assess the impact on light to neighbouring properties as a result of new development:

    These are:

    1. Diffuse daylighting to windows
    2. Sunlight availability to windows
    3. Sunlight availability to open spaces & gardens

    Using numerical modelling techniques, Herrington Consulting can accurately calculate potential impacts and provide a quantitative assessment that can be used to aid design and support the planning application.

  2. What are the advantages of undertaking a Daylight and Sunlight analysis?

    The detailed analysis will determine the illuminance within each room resulting from natural daylight enabling the calculated values to be compared against the recommended lighting levels for different types of interior space or specific visual tasks.

    It is also possible to uses these analytical techniques to examine the impact of new development on the daylight distribution within existing buildings. In this way the design process can be informed so that a scheme can be developed in the confidence that it will not have any significant adverse impacts on the amount and quality of daylight available to existing buildings.

  3. Are Daylight and Sunlight studies mandatory?

    No. There is no official national planning guidance / legislation on daylight and sunlight. However, the most recognised guidance document is published by the Building Research Establishment and entitled ‘Site Layout Planning for Daylight and Sunlight – A Guide to Good Practice’, Second Edition, 2011. The BRE Guidelines are not mandatory and themselves state that they should not be used as an instrument of planning policy, however in practice they are heavily relied upon as they provide a good guide to approach, methodology and evaluation of daylight and sunlight impacts.

    Additionally, some planning authorities require an assessment showing whether local playgrounds, parks or gardens will suffer from overshadowing as a result of new development. Using state-of-the-art modelling software, Herrington Consulting can simulate shadowing from any number of buildings and provide a quantitative assessment of the potential impacts of a new development.

  4. Can a Daylight and Sunlight study be used to quantify the amount of sunlight received in a particular location?

    Yes, detailed shadow impact assessments can be undertaken, which can show the shadow path of the sun throughout the day. Current guidelines suggest that “for it to appear adequately sunlit throughout the year, no more than two fifths and preferably no more than a quarter of any of the amenity areas should be prevented by buildings from receiving any sunlight at all on 21st March.” Shadow assessments can be used to ensure that new development does not adversely impact upon amenity areas.

  5. Can Daylight and Sunlight studies be used as part of a Code for Sustainable Homes assessment?

    Yes, the same analytical techniques can be used to demonstrate that the requirements of Hea1 can be met and thus achieve 3 credits.

    The objective of the Code for Sustainable Homes “Hea1 of Category 7”: Health & Well-being, is to promote good daylighting and thereby improve quality of life and reduce the need for energy to light the home. Currently, there are no mandatory elements to this section, although there are 3 points available if the following requirements can be met:

    • Kitchens must achieve a minimum Average Daylight Factor of at least 2%
    • All living rooms, dining rooms and studies, (including any room designated as a home office under “Ene 9 – Home Office”), must achieve a minimum Average Daylight Factor of at least 1.5%
    • 80% of the working plane in each kitchen, living room, dining room and study, (including any room designated as a home office under “Ene 9 – Home Office”), must receive direct light from the sky.