Understanding the daylight requirements in Clackmannanshire matters to anyone planning a house extension, an infill home or a larger residential development in Scotland's smallest mainland council area, whether that is in the historic county town of Alloa, the riverside at Kennetpans and Clackmannan itself, or the Hillfoots villages of Tillicoultry, Alva, Menstrie and Dollar tucked beneath the steep southern face of the Ochil Hills. Clackmannanshire Council is the planning authority for the whole area and assesses householder and residential applications against its adopted development plan. This guide explains how daylight, sunlight, overshadowing and privacy are considered locally, which policies apply, and what an assessment to recognised best-practice standards involves.
Daylight requirements in Clackmannanshire: the planning framework
In Scotland the statutory development plan has two parts. The first is National Planning Framework 4 (NPF4), adopted by the Scottish Ministers in February 2023, which forms part of the development plan nationwide. The second, locally, is the Clackmannanshire Local Development Plan, adopted in August 2015. A replacement local development plan is being progressed under the current plan-making system, but at the time of writing the 2015 plan remains the adopted local document and is read together with NPF4.
For daylight, sunlight and residential amenity the most directly relevant local policies in the adopted Clackmannanshire Local Development Plan are:
- Policy SC5 - Layout and Design Principles, which sets the criteria all new residential development must follow so that it is designed to high standards and contributes positively to its local environment, demonstrating "the qualities of successful places";
- Policy SC6 - Additional Design Information, under which the Council can require a Design Statement where a site or proposal raises particular design issues; and
- Policy SC8 - Domestic Developments, which applies specifically to extensions, alterations, outbuildings and means of enclosure for existing houses and flats.
Policy SC8 is the one most householders meet. It states that domestic development will normally be approved provided that, "by virtue of its siting, design, scale or massing", it does not adversely affect the residential amenity enjoyed by occupants of surrounding domestic properties, does not harm the character or appearance of the area, and does not result in over-development of the plot. Daylight, sunlight and overshadowing fall squarely within that test of residential amenity.
Supplementary Guidance 10: Domestic Developments
Clackmannanshire expands on Policy SC8 in its adopted Supplementary Guidance 10: Domestic Developments, which forms part of the Local Development Plan and is a material consideration. This is where the council is most explicit about light. Under the heading "Impact on the established amenity of neighbours" (paragraph 5.2.1) it states:
"Any proposed development should seek to avoid any significant overshadowing of neighbouring property, or loss of privacy. In reaching a balanced judgement on these issues, the Council will have regard to a variety of issues, including existing structures and standards of amenity, building height, proximity to boundaries and neighbouring properties, and the position, size and orientation of proposed windows."
The guidance returns to the theme for specific project types. For raised decks, terraces and balconies (paragraph 6.5.1) it notes that additional screening may reduce overlooking, but warns that the impact of any such screening on "the amount of sunlight/daylight received in the neighbouring property" must also be considered. The council also points to the High Hedges (Scotland) Act 2013, which gives neighbours a route to address a high hedge that blocks light to a domestic property. The relevant Supplementary Guidance 3: Placemaking sits alongside Policy SC5 and sets the wider design quality framework.
How NPF4 reinforces good amenity
NPF4 strengthens the design and amenity case. Policy 14 (Design, quality and place) asks development to be designed to a high quality that improves quality of life, drawing on the Six Qualities of Successful Places (healthy, pleasant, connected, distinctive, sustainable and adaptable). Good access to daylight and sunlight, and the avoidance of unacceptable overshadowing, are part of what makes a place healthy and pleasant. Policy 16 (Quality homes) seeks well-designed, sustainable homes and, for larger schemes, looks at how a proposal improves the residential amenity of the surrounding area. The local Clackmannanshire policies and the national NPF4 policies are read together as the development plan.
How daylight and sunlight are actually measured
The Clackmannanshire Local Development Plan and its supplementary guidance set out the amenity principles, but they do not prescribe their own technical method for calculating how much daylight or sunlight a window or garden actually receives. For that, the established methodology is the Building Research Establishment guidance, BRE BR 209: Site Layout Planning for Daylight and Sunlight - A Guide to Good Practice (2022 edition), read alongside the British Standard BS EN 17037 on daylight in buildings. These are the recognised UK best-practice documents and are routinely used by Scottish planning authorities, including Clackmannanshire, as the evidence base for assessing the overshadowing, daylight and sunlight impacts that Policy SC8 and the Domestic Developments guidance are concerned with. They translate the council's qualitative language into objective, repeatable tests.
A BRE-based assessment considers both the daylight and sunlight enjoyed by neighbouring properties and the conditions future occupiers of the proposed development will receive. The principal tests include:
- Vertical Sky Component (VSC) - the amount of skylight reaching the centre of a neighbour's window, with a guideline value of 27%, or no worse than 0.8 times its former value;
- Daylight distribution (the no-sky line) - how well daylight reaches across the depth of a room;
- Annual Probable Sunlight Hours (APSH) - the sunlight reaching windows with a significant southerly aspect, assessed across the whole year and during the winter months;
- Overshadowing of gardens and amenity areas - using the sun-on-ground test on the equinox, particularly relevant in the Hillfoots, where the steep north side of many gardens already sits in the shadow of the Ochils.
A clear, BRE-compliant report gives a Clackmannanshire planning officer the objective evidence needed to judge a proposal against Policy SC8 and the Domestic Developments guidance, especially its tests on building height, proximity to boundaries and the position and orientation of windows. It cannot promise consent, but it gives the council sound evidence on which to base a decision and helps applicants design out problems before they submit.
Common Clackmannanshire projects that benefit from an assessment
Daylight and sunlight questions arise most often where buildings sit close together or where new development changes the relationship between neighbours. Across Clackmannanshire these typically include:
- Rear and two-storey side extensions in the older streets of Alloa and Clackmannan, where terraced and semi-detached homes share boundaries;
- Extensions, dormers and raised decks in the Hillfoots villages of Tillicoultry, Alva, Menstrie and Dollar, where the steep slope of the Ochils already limits low winter sun;
- Infill and backland housing that introduces a new building behind or between existing homes, where over-development and loss of light are common objections.
Presenting a BRE-based assessment up front helps an application run more smoothly and shows officers and neighbours that amenity impacts have been taken seriously.
How Fortress Associates can help
Fortress Associates prepares our daylight and sunlight report service to BRE BR 209 (2022) and BS EN 17037 for projects across Clackmannanshire, including Alloa, Clackmannan, Tillicoultry, Alva, Menstrie and Dollar. We work nationwide with a typical 4 to 5 working day turnaround and ask for no advance payment. You can see the full range on our services page or contact us to discuss your site. Where a project also needs building warrant drawings under the Building (Scotland) Regulations and the Scottish technical handbooks, we can prepare those too. If your work spans more than one Scottish council, our sibling guide on the daylight requirements in Argyll and Bute may also be useful.
Sources & further reading
- Clackmannanshire Council - Local Development Plan (adopted August 2015) and supplementary guidance
- Scottish Government - National Planning Framework 4 (NPF4)
- BRE - BR 209: Site Layout Planning for Daylight and Sunlight (2022)
- Fortress Associates daylight and sunlight reports
- Our services and how to get in touch
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