Following Margaret's article on needing a tool store, I thought I'd pass on our experiences. We were extremely lucky in that the woodland we bought had a derelict building that had formerly been a dwelling, and then stables. There was also a derelict but still-standing wooden shed (formerly a goat shed). Best of all, we managed to find, buried by brambles and grass, a large concrete base. Examining old maps showed that this used to be a pig shed, and was built about World War I.
We needed a home for our tractor, as it was living on our patio in a semi-detatched garden, and commuting rather perilously to work each time we needed to use it. We also needed a base for our other tools. We decided for all sorts of reasons that restoring the derelict former dwelling and making it into a tractor shed was not realistic - for one thing it was too low to take the tractor. Therefore we applied for planning permission for a steel barn, similar in design to those on the adjacent farm which were visible from the road. We were very careful to ensure that the building would fit exactly onto one end of the large concrete base. The only reason planning permission was granted was because we would not be placing a new area under concrete - we were using an existing area, although we did replace the concrete with new concrete that was sound enough to take the structure.
At the same time we had to do a lot of other work - we had to move the road entrance to a place that was much safer than the existing entrance (on a blind bend on a national speed limit road that was used as rally practice by the local Subaru Impreza owners' club), and build an HGV capable road from this to the new building (this was a requirement by the Forestry Commission who supported the planning application). This was not cheap. We had to satisfy the Environment Agency of our plans for drainage of water from the roof (into a series of ponds and thence into a ditch rather than directly into the ditch). It took about 9 months to get all the permissions in place, but we now have a lovely steel building to keep our tractor and tools in. There have been a few break-in attempts, but we have fitted a battery powered alarm system, and in due course will fit solar panels (for which we got planning permission).
They cannot stop us restoring the former dwelling or the old goat shed. We have started on the latter by burying the remains of the asbestos roof (you can do this legally if you are the land owner and record where it was buried), and clearing the scrub around it. We will re-roof it this winter and use it as a wood store. The former dwelling will take a lot of money, but if we get a forest school started, or other community groups using the wood, it would make a good education base if it could be re-roofed.
If you want to build storage, I'd go along with the advice to work the wood for a bit without a building. I'd also look very carefully at old maps to see if there has ever been an old building there - our concrete base was not visible at all until we discovered part of it, and the extent was not apparent until we looked at the old maps.
You will also need to look very carefully at security on an unattended site. We have an alarm that phones our mobiles when it is triggered. The local scrotes will definitely find it and will try to break in to see what you have stored there. If you store tools in a wooden building they will simply saw through the wall. Therefore you need to have them securely locked away in a steel site-box and have that site-box chained to the floor via a ground anchor arrangement. We set in several ground anchors in our building and chain the tractor down whenever we leave it.
Having a building has improved our productivity hugely. It would take an hour to get to the woods with the tractor and another vehicle, open up, drive the tractor to where we park the implements, hitch up an implement and start work. Another hour the other way. As we both also have day jobs this took too much out of our already limited available time. Now we can just turn up, jump on and do work. We also don't need to direct traffic in and out of the site.
The local planners are gradually getting the idea that we don't want to build a supermarket there, nor cut down all the trees. It just takes a while to win them over! It has definitely been worth it.