How to create an AR app that augments on buildings?

Hello ! So first things excuse my noobiness. I am a CS Students but I am just lately getting the AR field. So, I am trying to create an app that uses geo-location AR to first detect the buildings that the user is looking at , and then Augments some graphics on the detected buildings. After some research, I have reached multiple conclusions: 1- Vfouira is a good option to detect images 2- SIFT algorithms can also be used to not only detect buildings but also set the start and finish of the buildings. 3- Augmenting on a large buildings is likely really hard to do right now.

According to your experience. 1- What should I use to do such a project? 2- How can I tackle this project? Thank You!