Basement in dha karachi

Is it preferable to construct a basement in dha karachi, specially if the plot is opposite to a storm / sewer drainage, like within 30-40 feet of it? (phase 7)

Kindly elaborate on the pros and cons and actual usage / value for money / resale value benefit from your own experience of having basements in your karachi homes?

How much is the estimated total cost of such basement construction for 300 sqy plot?