The group hopes to use the former bar area on the ground floor as a community hall for meetings and youth club events, while the first floor is intended to be used for classrooms.
The Facebook post said: "The generosity of our community has never ceased to amaze us and we truly feel blessed to be a part of it.
"This is a major milestone for WISE, heralding a new chapter in our history. The new premises will provide a desperately needed facility serving a wide range of essential community and educational activities, all run in accordance with an overarching Islamic ethos.
"We will start some refurbishment and repairs of the premise immediately."
Before the project can be officially completed, WISE would need to apply for a change of use for the property from Wycombe District Council.