Envision strengthens its Daylight and Sunlight capabilities

At Envision we are continuing to strengthen our capability in daylight and sunlight analysis with an ongoing work stream both for planning and BREEAM purposes.

An example of our capability is detailed below, where Envision has played an integral role by influencing the design in order to increase levels of natural light.

LCS London comprises an abandoned Victorian warehouse, which has long lost its roof and windows but retains the outer wall along with distinctive windows arches. This innovative development will see new student accommodation built within the confines of the original Victorian walls, which will act a distinctive design feature.

Owing to this unique design, concerns were raised as to whether sufficient levels of daylight will be present, in particular in the ground floor rooms, which are the most severely affected by over shading of the retained wall. Envision were employed to conduct daylight assessments to determine the levels of light and propose solutions if low levels were found.

The main reference used to determine the acceptability of proposals in terms of their internal daylight is the Building Research Establishment (BRE) Guidelines, used in conjunction with British Standard BS8206 Part 2. The initial daylighting analysis carried out by Envision was by calculating the Average Daylight Factor (ADF);

Initial studies showed that all bedrooms and kitchens exceeded the minimum Average Daylight Factor (ADF) threshold of 2%, in accordance with the best practice levels as outlined in BS8206.

Envision determined that in the ground floor rooms, the uniformity ratio and point daylight factor (alternate BREEAM methods of calculating daylight) were non-compliant. This would suggest that owing to the retained wall, natural light penetration is poor in these ground floor rooms, leading to poor lighting uniformity.

This could be seen in graphical representations, where a daylight factor above 10% was present directly adjacent to the window, whilst a majority of the room has a daylight factor below 2%, leading to poor point daylight factors and lighting uniformity.

Design development is ongoing but initial design measures put forward by Envision included

1. Increasing Light Transmittance (LT) value of proposed glazing;
2. Increasing window size;
3. A shallower room floor plate with an option for an atrium to the rear for access/communal spaces.

Envision will undertake more detailed studies, including calculation of Vertical Sky Component (VSC) as the project develops in order to ensure the development enjoys the highest possible level of natural light.