Brick foundation

[arupd123]

Hello,

My parental house is in Calcutta, some details are as follows:

House foundation details are:
a) Number of existing floors = 2
b) Width of foundation: 36"
c) Type: Brick foundation
d) Depth of foundation: 4 feet from plinth level
e) Condition of house: Excellent, very strong
f) Walls: 1st floor: load bearing walls = 10 inches
g) Walls: ground floor: load bearing walls = 10 inches
h) Age of house: 45 years
i) Soil condition = good
j) There are many 40+ year old houses in the neighbourhood with 3+ storeys

My questions
1)If I add another floor to my house will that be risky?
2) What should be the thickness of the load bearing walls that I should use for the second floor?