I'm duplicating this response from a previous one posted by Samboradford, its more appropriate here.
This member is doing the right thing - a licensed manufacturing set up is the only way to proceed in my opinion, and it's not beyond the reach of most people with the land to base their activities on.
The process involves:
1. Plan your site / planned activities and ambitions.
2. Set up a company to hold the licence.
3. Draft the license - this is the biggest part of the application process. You will need building schedules, plans - site and location, licence schedule (setting out what will be made, used in manufacture or brought in and stored)
4. Prepare a safeguarding plan - not needed yet but do it all the same as this will illustrate clearly where you stand in the location and who might be affected.
5. Establish the position in regards to planning - refer to the safugaurding plan and make it available to the planners - they will need it eventually anyway.
6. Submit with fee.
7. Wait (and wait).
If the draft has been produced properly - that comes with experience or can cost a lot - the process can be minimised at the Inspectorate end. Our last application cost £360 from memory in inspectors time.
By the time the license is granted you will receive a certificate - I kept mine for years as a keepsake because it was nicely set out then lost it, you get so long to pay up the final fee for time then the license is issued, usually with a caveat that nothing can happen until the first inspection. This gives you three years to get the fabric of the place up and running - at least the bits you want up and running to allow you to operate legally.
Our last big variation created a number of ambitious additional magazines, our latest removes them - they existed on paper and are being removed without ever existing!
It needn't be a headache - although when I first applied in 1995/6 they didn't ask about planning, that came after the application was made. I might suggest that if you have a suitable location you:
1. Ensure it's suitability - or else risk wasting your money at the end of the day.
2. Site a magazine and small shed as soon as possible thereby establishing prior use.
You may find objections on the forum to these last suggestions but they worked for me.