Two skylaterns and patio sliding door

i have a 4.1×2.1 meter sliding door, a 0.9x 2.1 fixed window and a 4×1.5 meter sky lantern for my 36 square meter extension. Would this be an issue for buildint control as i understand i have to 25% of the total extension. I am also thinking about adding another 4×1.5 sky lantern but not sure if id fail building control.

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Answer:

When it comes to building regulations and requirements for skylights or sky lanterns, there are typically guidelines regarding the total glazed area allowed as a percentage of the floor area. The purpose of these regulations is to ensure adequate natural light and ventilation while maintaining thermal efficiency.

Based on the dimensions you provided:

– The sliding door has a glazed area of 8.61 sq.m. (4.1m x 2.1m)
– The fixed window has a glazed area of 1.89 sq.m. (0.9m x 2.1m)
– The first sky lantern has a glazed area of 6 sq.m. (4m x 1.5m)

The total glazed area with just these elements would be 16.5 sq.m. (8.61 + 1.89 + 6).

For a 36 sq.m. extension, the 25% glazed area limit would be 9 sq.m. (0.25 x 36).

So, with just the sliding door, fixed window, and one sky lantern, you would exceed the 25% limit.

Adding another 4m x 1.5m sky lantern would increase the total glazed area to 22.5 sq.m. (16.5 + 6), which would significantly exceed the 25% limit.

However, it’s important to note that building regulations can vary depending on your location and specific requirements set by the local authorities. Some areas may have different or additional criteria, such as thermal efficiency standards or specific requirements for roof lights or skylights.

To be certain, it’s best to consult with your local building control department or a professional architect or contractor who can review your plans and provide guidance based on the applicable regulations in your area. They can assess your specific situation and advise you on the best course of action to ensure compliance.