For most engineers and designers, the main attraction of being a contractor is money. The prospect of earning twice the rate or more than a permanent employee is inviting. Average engineering rates are around £45+ per hour, though these vary depending on your experience, geographical location and current market conditions.
There are other considerations. Contractors can, when the market is buoyant, choose their contract location and duration. They can also decide the length of their holidays. This greater freedom brings a major responsibility; you have to find work. This can be easy when many projects are underway, but can be difficult at other times. Additionally, you will have to manage your own finances, which may perhaps involve dealing with an accountant, filling in tax and VAT forms etc.
Going contract can be a step in the dark.
You have to give your notice to your present employer. You will no doubt have to work your month's notice. This month can be put to use though.