Hello,
I do not have experience if retouching buildings alone. I do have experience removing vehicles and objects from in front of buildings, retouching skys, blending color, digitally altering backgrounds. I believe I can apply these skills to what you will need. If you would like, please send a sample image, and I can provide a sample of my work. I work quickly and provide professional work, and I am stateside to help you with any concerns quickly. Your work does interest me. If my skills may be of benefit please allow me to try and see if I may be of benefit.