Since $a_{n+2}=5a_{n+1}-6a_{n}$,

We can derive that $a_{n+2}-2a_{n+1}=3(a_{n+1}-2a_{n})$,

And $a_{n+2}-3a_{n+1}=2(a_{n+1}-3a_{n})$,

Given that $a_{2}-2a_{1}=3$, $a_{2}-3a_{1}=-2$,

We can conclude that the sequence $\{a_{n+1}-2a_{n}\}$ is a geometric sequence with the first term $3$ and common ratio $3$,

And the sequence $\{a_{n+1}-3a_{n}\}$ is a geometric sequence with the first term $-2$ and common ratio $2$,

So, $a_{n+1}-2a_{n}=3^{n}$, $a_{n+1}-3a_{n}=-2^{n}$,

Thus, $a_{n}=3^{n}+2^{n}$, which also holds true for $a_{1}=5$;

Hence, $S_{n}=(3+2)+(4+9)+…+(3^{n}+2^{n})$

$= \frac {3(1-3^{n})}{1-3}+ \frac {2(1-2^{n})}{1-2}= \frac {3}{2}(3^{n}-1)+2(2^{n}-1)\geqslant 2016$,

So, $n\geqslant 7$,

Therefore, the answer is: $\boxed{7}$.

By simplifying $a_{n+2}=5a_{n+1}-6a_{n}$, we get $a_{n+2}-2a_{n+1}=3(a_{n+1}-2a_{n})$, $a_{n+2}-3a_{n+1}=2(a_{n+1}-3a_{n})$, from which we can deduce that the sequences $\{a_{n+1}-2a_{n}\}$ and $\{a_{n+1}-3a_{n}\}$ are geometric sequences.

This problem tests the understanding and application of sequence properties, overall thinking, and transformational thinking, as well as the application of the construction method.