Almost right Simon. Having recently talked to the planners to familiarise myself with the process, its fresh in my mind.
The process is called prior notification, exercising your permitted development rights. However the council planning officers are involved and have to approve the application, they don't just automatically rubber stamp it. Unlike a full planning application it comes under less scrutiny, doesn't have to be passed by planning committees and can be approved by a planning officer within 28 days. However it does require a form to be filled in, plans to be submitted and a modest fee paid (£80). You have to submit a plan of the building, stick to it and erect it within a given time frame. They may come out to inspect the site.
In my case I found an informal chat laid the ground for an eventual successful application. Although I knew I was entitled, they still ran me through the standard questions, height of building, proximity of roads. They also asked why I needed it, and I said firstly I was entitled to it and that it was necessary as the wood hadnt been managed for many years and there was extensive work required, needing lots of bulky tools and somewhere to shelter between showers or when taking breaks between work. They were quite satisfied, although I've not submitted a detailed plan yet as I haven't finalised my building design, one of the requirements.
Always best to talk to them and establish what their view is and the procedure, they like to work with people who listen but take a dim view of applications that ignore the rules, as many do.
As I said before, whatever you chose to do in your toolstore and shelter, do not refer to it as a workshop, that isnt allowed, its a commercial manufacturing use, not agricultural. What you actually eventually do there is a different matter.
This is the form for my local area.
http://www.planningportal.gov.uk/uploads/appPDF/R3325Form016_england_en.pdf
