Overshadowing

Overshadowing vs loss of light

Loss of light generally concerns daylight reaching windows and habitable rooms, while overshadowing generally concerns the impact of shadow on gardens, patios and other outdoor amenity spaces. A development can cause meaningful overshadowing to a garden without technically failing a window daylight test, and vice versa, so it’s worth being precise about which you’re objecting to.

Where daylight and sunlight assessments are undertaken, they often draw on BRE guidance, which commonly uses the spring and autumn equinoxes as reference points. The approach adopted can vary between councils and developments - a proposal that leaves a garden substantially in shadow even at the equinox is a stronger case.

What strengthens this objection

• Identifying which specific outdoor space would be affected, and roughly what proportion of it and for how much of the day
• Describing the current use of that space (a main garden or patio used daily carries more weight than an unused side passage)
• Relating the shadow directly to the proposed structure’s height, depth, and position relative to the sun, rather than just its overall size
• Requesting or referencing a shadow/sunlight study if the application is large enough that one hasn’t already been submitted

Where it tends to fail

A brief, partial reduction in afternoon sun to a corner of a garden is unlikely to be treated as significant on its own. Objections that describe the development as simply “blocking the sun” without saying which space, for how long, or at what time of year carry far less weight than ones that engage with the actual pattern of shadow the proposal would cast.

A worked example of a weak objection versus a strong one

Weak: “The extension will overshadow our garden and ruin the only outdoor space we have.” Understandable, but it doesn’t tell the case officer which part of the garden, when the shadow falls, or how the proposal actually causes it.

Strong: “Our garden faces north-east and is currently in direct sun for most of the morning. The proposed two-storey side extension, shown on the submitted elevations as roughly 5.5 metres to eaves, would sit along our shared boundary and, given its height and proximity, would cast shadow across the majority of our garden’s useable area - including the patio directly outside our kitchen door - for most of the morning period when the space is currently in sun. This is the part of the garden we use daily and the part that currently receives most of our available direct sunlight.” The second version gives the case officer a specific area, a specific time of day, and a specific structure to check the claim against.

Common mistakes to avoid

• Conflating overshadowing with loss of privacy or loss of view - these are separate material considerations and mixing them into one vague complaint weakens all of them
• Objecting on the basis of shadow at one specific time of day (e.g. early morning or late evening) without acknowledging that some shadow at the extremes of the day is normal and rarely determinative on its own - the stronger case is usually shadow during the core part of the day when the space is actually used
• Not mentioning how the space is currently used - a case officer weighs impact on a garden used daily for sitting out very differently from a side strip used for bins
• Overstating the impact (“it will be in permanent darkness”) when the honest description is a substantial but partial reduction - exaggeration is easy for a case officer to dismiss once they check the plans, which can undermine the rest of an otherwise reasonable objection