The use of HDRI maps for rendering in architecture is a great way to add realism to a scene, using real-world information to the lighting of a project. The so called Image Based Lighting is fully supported by Blender Cycles, which means that we can use those maps to add light information to our scenes. All you need is a good HDRI file with a big resolution to start playing around. If you don't have any HDRI maps on your library, I found an interesting resource for you. The guys from 3D Scan Store are offering three high-resolution HDRI maps for download. All three maps are free to download, but you must add them to the shopping cart at their store, and choose free checkout as payment.
I'm not sure for how long those files will be available as a free download, so hurry up and copy them to your library now.
thnx