Light Loss and Overshadowing Assessment for Proposed Development

This study evaluates the potential impact of our minor building alteration on light levels to surrounding buildings, ensuring no loss of light or overshadowing occurs.

The proposed minor building alteration involves modifying the existing extension by replacing the current double-pitched roof with a flat roof configuration, maintaining the overall height of the extension at the same level as the top ridge of the existing pitched roof.

Specifically, the extension will be converted from a double-pitched roof to a flat roof. The height of the flat roof will align with the existing top ridge height. While this adjustment raises the edges of the extension, it remains essential to confirm that no overshadowing is caused to neighbouring properties.

The study is conducted using computer-generated images (CGIs) of the existing building and the proposed flat roof extension. Dormer windows are shown in the CGIs as part of a broader possible modifications of the building, but this assessment focuses exclusively on the flat roof extension. Previous loss-of-light studies have already been completed for the dormer windows and confirmed that no loss of light and overshadowing are caused by any possible dormer window on the main roof too; however thjjis is not he scope of this particualr staudy.

The properties along Harold Street are identified as the primary area of concern. As such, the verification process is limited to these properties. If the 45-degree rule is satisfied for all windows of the buildings facing Harold Street, it can be concluded that no overshadowing will affect other surrounding properties, which are further away.

The most critical aspect of this study is the assessment of ground-floor extension windows at 70 Harold Street and 74 Harold Street. If these windows meet the 45-degree angle rule and do not intersect the extension, no loss of light or overshadowing will result from the proposed development.

 

Explanation: 1.1

 

This 3D visualization demonstrates a shadow analysis for a proposed flat roof extension, focusing on its impact on neighbouring properties. The beige building represents the modified structure. The “7.5m” measurement highlights the distance between the extension and the nearest structure, ensuring compliance with light regulations such as the 45-degree rule. The angled projection line assess whether the shadow affects the windows or critical areas of nearby properties, particularly those on Harold Street, confirming that the development does not cause any loss of light or overshadowing. the 45-degree test conducted from the ground-floor extension window of 70 Harold Street, representing one of the worst-case scenarios for potential overshadowing. As this window passes the test, it is anticipated and confirmed bby other studies that all first-floor windows also meet the required standard, ensuring no overhadowing implications for the neighbouring properties.

This image show another angle of a shadow analysis for a proposed development. The triangular projection from the window is at 45 degree angle and it goes past the buiding, therefore ensuring no loss of light is caused to the particualr window that could potentially be affected most from it.

Explanation: 1.2

This image illustrates one of the most critical windows that could be considered at risk of failing the 45-degree angle test (overshadowing/loss of light). However, upon analysis, it is evident that this window comfortably passes the test. Based on this result, it is reasonable to conclude that all other windows on both the ground floor and the first floor of the surrounding properties will also pass this assessment without issue (this also had been verified).

Therefore it is demontrated how all the windows of the properties facing Harold Street successfully meet the 45-degree angle test with a considerable margin. This confirms that the proposed roof alteration to the extension does not cause any overshadowing or loss of light to the nearby properties. The results provide clear evidence that the modification has been carefully assessed to preserve the natural light to neighbouring buildings, thereby ensuring compliance with overshadowing regulations and safeguarding the amenity of the local residents.

 

The above image shows how the second floor back window of 74 harold street as expeced passes the 45 degree angle test as it comfortably passes the top of the building. The 45-degree angle test, ensures that no overshadowing occurs at rear of the properties facing Harold Street.
Therefore this minor modification to the extension roof does not negatively impact the daylight access to any of the windows at the back of the properties facign Harold Street. As we will see all other the windows pass the 45-degree angle test with ample margin, proving that the extension alteration doe not cause any loss of light, therefore no claim of overshadowing could be successful.

 

 

 

 

Explanation: 1.3

 

The above Direct line measurement to the extension is (9.7 m). Once again it is clear how the 45 degree test is amply passed. The line passes the roff of the building from a first floor window with ample margin.