Apply different tsconfig rules on a subfolder

Question

I am working on a project which was not typesafe earlier, but now i want to make it typesafe using Typescript . Since the project is very big so i would be doing it in parts . So there are many sub folders which i will be working on one by one . I want to set strict tsconfig rule in the subfolder which is different from the root tsconfig. How can this be done ?

Liederman