can i cancel irrevocable power of attorney given by my grandmother

My grandmother sold the property to builder for developing new building and give the builder irrevocable power of attorney but after 15 years he still not develop the building on that property . And my Grandmother is also dead . So ,i want to know after 15 years can i cancel the irrevocable power of attorney made by my grandmother and builder and under which section ? and i like to know after person dead irrevocable power of attorney will get cancel automatically and if yes then under which section ? thanks for help..