Having pl.Area = 1800 sq.m. If the cost of construction of the recently constructed building in that region is Rs. 2 crore 20 lacs for 1000 sq.m construction.

Given:

Plint area of proposed building = 1800 sq.m Plint area of the constructed building = 1000 sq.m

Cost of recently constructed building = 2 crore 20 lacs.

Therefore, plinth area rate = $\frac{cost \hspace{1mm}of\hspace{1mm} constructed\hspace{1mm} building}{plinth \hspace{1mm}area\hspace{1mm} of\hspace{1mm} the\hspace{1mm} building}$

= $\frac{22000000}{1000}$ = $22000$

Approximate cost of proposed building = plinth area * rate = 1800 * 22000

= 3 crore 96 lacs