Understanding apartment areas is key before buying. Carpet Area: Usable area inside the walls. Example: 1 BHK size carpet is ~450–550 sq.ft. Built-up Area: Carpet area + walls & balconies. Example: standard size of 2 BHK flat built-up ~950–1,100 sq.ft. Super Built-up Area: Built-up + proportion of common areas (lobby, staircase). Difference between RK and BHK: RK has single room + kitchen; BHK has separate bedrooms, hall, kitchen. Knowing difference between 1BHK and 2BHK helps choose space wisely. Conclusion: Check carpet, built-up, and super built-up areas. Compare 1 BHK size vs 2 BHK and understand difference between RK and BHK to pick the right home.