Windows Radiance

Radiance is a software package comprising some 120 individual programs. Currently, only UNIX-like platforms, e.g. LINUX and Mac OSX are officially supported. Efforts are underway by the National Renewable Energy Laboratory (NREL), to bring Radiance to the Windows platform as part of their OpenStudio whole building energy modelling Sketchup plug-in.

Radiance is Open Source software, so you can download, modify, and compile it for your platform of choice.

Radiance can be downloaded from

Whilst a large part of Radiance is written in the C programming language, there are also many scripts that utilise those C programs, combining them in order to make them more flexible or user-friendly. Those scripts were historically written in C shell. Newer Radiance scripts are written in the Perl scripting language.

This creates a problem Radiance users under the Windows operating system. Both C shell and Perl either come as standard on UNIX systems, or can be installed very easily. Windows users, on the other hand, are not as fortunate. The C shell does not exist for Windows, and Perl is a prerequisite that needs to be installed and configured correctly for those scripts to work.

The two most popular Perl distributions for Windows are:

Although there is no simple fix for the C shell dependency, it is possible to package Perl scripts in such a way that they do no require the Perl interpreter. This is done with Perl's PAR::Packer module. This packages the actual Perl script and the Perl interpreter, as well as all modules that the script relies on, into a Windows executable.

Packaging a Perl script under Windows is as simple as running

pp -o falsecolor.exe

in the Windows command shell.

Unfortunately, this packaging does not work for cross-platform binaries. It is, for intstance, not possible to prepare Window exe files on a LINUX server.

Porting Radiance C shell scripts to Perl

! If you would like to see more of the Radiance functionality available to Window users, please consider porting one of the C shell scripts to Perl.

You might want to ask a friend or colleage to help you with this. The current status of the Perl porting is accessible here. As you can see, there are LOADS of scripts that do not run under Windows yet. Please feel free to get in touch if you would like to contribute.


The file naming of the Zip archive adopts the same versioning as the NREL Radiance installers. The executables were built on a 64-bit Windows 7 machine. They will not run on a 32-bit system, or on older versions of Windows.

The man pages are accessible in HTML format from the Radiance community web portal.