Implementation of new daylight metric in accordance with European standard

Hello everyone,

I’m working on a Daylight Autonomy analysis (DLA) for a reference year. The script works fine, but I need to sort my .ill files and only use the 50% with the highest values. I currently have 8760 hours of data (one year), but only need the 4380 highest values as an input for the readAnnualResultsI component.

Can anyone help me with this?


  • Ida

Are you trying to calculate DA for Danish standard? If that is the case you should generate the schedule using the weather data.

cc: @Mathiassn and @tobiaspedersentsp

Yes, excactly. The standard says “The daylight hours are defined as the half of the yearly hours with the most daylight”.

How can I generate a schedule using the weather data?

New European Standard, works all over EU… or will :smiley:

Hi all - here is the solution to calculate the new daylight metric using HB+:


Thanks a lot Tobias - I will look into it.

Do you know if the DNK_Copenhagen.061800.epw weather file is equivalent to the Danmark_2013.dry weather file?

No problem - let me know if an example file would be of help

If you are refering to: DNK_Copenhagen.061800_IWEC.epw ( this weather file is from the IWEC 1 project and contains “representative”/typical weather data from 1983-1999.

DRY 2013 (Wang et al., 2013) is from the period 2001 - 2010

According to the danish building regulation you should use DRY 2013:

So if you are looking for DRY 2013 in epw format, try to contact SBI - they are responsible for the distribution of the DRY 2013 data. If they can’t help you with that, get back to me and I might be able to help you.

1 Like

Hi again,

I’ve tried SBI but with no response so far. But I’ve talked to one of my teachers, who is also working for SBI - and he says they don’t have DRY 2013 in epw format.

If you are able to help it would be highly appreciated :slight_smile:


Below you will find DRY2013 in epw format. It was created by downloading the DRY dataset from SBIs homepage (back when the data wasn’t encripted). Only the Diffuse Horizontal Radiation and Direct Normal Radiation has been been transferred to the epw format, using DNK_Copenhagen.061800_IWEC.epw as a “template”, therefore the dataset below CAN ONLY BE USED FOR DAYLIGHT STUDIES.

This works becuase honeybee only uses the Diffuse Horizontal Radiation and Direct Normal Radiation when calculating using Radiance.

Use it at your own risk: DRY2013.epw (1.4 MB)

In order for you to find the daylight hours, first step is to run an annual illuminance simulation of an unobstructed horizontal surface, to get the Diffuse Horizontal Illuminance. And then rank order them to find the 4380 hours with the most Diffuse Horizontal Illuminance as your daylight hours.

If you have futher questions let me know

Thanks a lot Tobias :slight_smile: