Tag Archives: Sunlight Daylight

Equivalent First Zone – Right to Light

Equivalent First Zone – Daylight Assessment

For many years we have been using the old paper and pen method to calculate VSC (Vertical Sky Component) and APSH (Annual Probable Sunlight Hours) and for many sites it is still possible to use this method.

However, the new BRE 209 guide has migrated from ADF values to far more complex calculation requirements, which are now only possible to do with a computer model.

Equivalent First Zone

For a long term client we have also offered to calculate Equivalent First Zone values for Existing vs Proposed Site Layout. This has been a steep learning curve for us, but we have managed to produce several sets of Equivalent First Zone calculations that indicate the maximum building possible to achieve, without compromising right to light.

So time moves on we miss our pens and our paper, but it is plain to see that the computer model does an extortionary volume of calculations in no time at all, and can derive values for very complex layouts where we mat have struggled in the past, and Equivalent First Zone Calculations they can carry out a days worth of calculations in just a few seconds.