We are finishing our basement and would like to enclose our electric furnace in a storage area. We would like to run a wall right along the side of the furnace, with a door in the back of it for access and also the door to the storage area which would be in the front of the unit. Is there a minimum requirement of wall space for an electric furnace? (for the side of the furnace) Any suggestions would be greatly appreciated!

The answer to that is contained in the manufacturer's printed instructions. If you haven't got them, you may be able to find them online. Get the model number from the nameplate on the furnace, and try the manufacturer's web site. Often they are available for download. If not, contact the manufacturer and ask if a copy of the installation instructions are available, or at least, ask what the recommended clearances are. In cases like yours, the manufacturer's instructions essentially become the code which governs. They need to be followed. Heat-producing appliances are not to be messed with absent that knowledge.

There are minimum requirements from each manufacture of these units. Also Code requirements.

Typically three inches of clearance on the three sides that you do not need to access and the distance of at least the total debth on the service side. However if you have a full door, in front of the unit and its ONLY a electrical air handler with coils, then a full door with a clearance of six inches should be ok. BUT check the manufacture requirements and codes.