Ask HN: How to grow a one-person business and hire more people when contracting?

I am contracting in the UK since 2012 and providing software development services but I am a one-man limited company and working for companies as if I am a permanent employee for them since most of them requires me present on the premise.

So the question is: How I can turn this 9 to 5 work routine in a multi-person, multi-contract operation that I could get contracts from companies and send my people to in my place.

Some things to consider;

* I am earning enough but not enough to cover the costs of an additional employee.

* I always get my contracts through recruitment agencies so I don't have a vast network I can reach to.

* I don't have much knowledge about the enterprise world, so don't know how to get 5-6 figure contracts from them.