Let the surface area of the larger dog house be represented as \( S \).
Since the smaller dog house is 1/2 the size of the larger one, its surface area will be \( \frac{1}{2}S \).
To find out how much smaller the surface area of the small house is compared to the big house, we can calculate the difference in their surface areas:
\[ S - \frac{1}{2}S = \frac{1}{2}S \]
Now, to express this as a fraction of the surface area of the bigger house:
\[ \text{Difference in surface area} = S - \frac{1}{2}S = \frac{1}{2}S \]
The fraction that represents how much smaller the surface area of the small house is compared to the big house is:
\[ \frac{\frac{1}{2}S}{S} = \frac{1}{2} \]
Thus, the surface area of the small house is \(\frac{1}{2}\) smaller than that of the big house.