This paper investigates the problem of requirement interactions which occurs due to negative relationships between requirements when developing software systems. This paper presents IRIS-TS (Requirements Interactions using Semi-formal methods - Tool Support) which identifies and detects requirement interactions using semi-formal methods in any software domain. IRIS-TS is implemented as an independent add-on module that can be added to DOORS (which is one of the most famous and commonly used requirements management tools). This paper presents also a case study in which the proposed IRIS-TS approach was successfully used as an add-on module in DOORS to detect interactions between smart homes requirements which represent a new application domain for interaction detection. The presented case study is the first comprehensive effort to fully detect interactions in the smart homes domain.