The single most important thing to keep in mind when starting to plan your workshop and toolstore is don’t rush. You may have to live with a mistake for a long time if you do! Talk and plan with other members of your group. Look around your local area and talk to people who may be able to give you guidance and practical help.
Keep in mind two points: storage and expansion.
If you don’t plan for adequate storage space now, then bench surfaces have a nasty habit of becoming shelves. You will be forever clearing away odd bits and pieces just to get at a work surface. You’ll find that new volunteers will be put off by what will appear as an untidy pile of odds and ends. As a result they will be reluctant to become involved with tool maintenance or van loading. You will also be forever looking for things because somebody else will have moved them to find work space!
The chances are that you will have to live with the space you acquire for some time. Look at the conservation projects you run now, and also those you hope to run in the future. You may well attract larger numbers of volunteers and start different types of projects to those you are currently running. This will mean more and different types of tools, a bigger storage area, and more broken tools waiting to be mended. Hopefully it will also mean more volunteers trying to find room around the workbenches.
Expansion could well mean a change in how you use the area. You may be running things on your own at the moment, mending tools as and when you can, and van loading may be something you do half an hour before you leave. Eventually you may envisage a regular evening or weekend session packing or repairing tools. This will involve you in training people who are not familiar with using workshop tools. You may have to set up a routine for repair and return of tools to the main storage area; you will certainly need more workbenches than you have now. So think carefully how you want the workshop to run, and how it fits in with your overall programme. This will in turn greatly affect the list of requirements which you draw up.