Thanks for the response guys.

So from what I am gathering, reason porches are more popular is for the extra open space?

I am in the process of purchasing/designing/renovating two single storey terrace unit (one corner). 500sq meter. Overall it's about 21m deep with a 16m flat frontage and another 7m but at an angle.

I am very much fixed on wanting a garage, but I wanted to know if there are any drawbacks that I am unaware of.

These are the few drawbacks that I know of:
Costlier - more materials required
Heat - Enclosed area, making it an oven during day time, easily fixed with proper insulation + air flow, I am sure
Size - Aesthetically not as pretty
Natural Light - It takes up precious wall space, and so it will give you that much less windows

My idea at the moment is to have the garage built up at the front of the inner unit (6m wide frontage, perfect size for a standard garage), sharing walls with the neighboring terrace. That will still give me another 17+m of ground floor entrance.

Thanks everyone for their input, really appreciate it.