If you don't have much room in your work space and don't need a bench all the time then this is the perfect solution. The bench is designed to fold down and only sticks out about 100mm on the wall when stowed. Of course all dimensions are customisable to your needs!
You don't need much in the way of woodworking skills for this either - you just need know how to nail and screw things together.
NOTE: if you going to make this type of bench make sure your floor and walls are reasonably level, straight and square to each other or you won't be able to swing the legs out evenly.
Step 1: Select Your Wall
This is the wall on which I placed my bench. Fortunately for me the wall was plywood over a timber stud frame, though it shouldn't really matter what type of wall you have as long as you have the right fixings for it.
Step 2: Build the Legs
Firstly, build your 'legs'. I just used some cheap 2x4 from the hardware store as well as some offcuts I had lying around. The nail plates are probably optional in hindsight, as you can just skew nail the timber together and the join will be just as strong. I only used the plates on one side here and skew nailed the rear.
Things to watch out for:
1) Make sure the gap at the top of each 'leg' is big enough to accommodate your wall fixing (in my case it was a length of 2x6 timber upon which I hung the bench). The area I mean is shown by the green arrows.
2) Make sure the legs are less than half the width of the bench you have so that they will fold in without obstruction. It's important they're about 4" shorter than half the width of the bench so they've got space to fold out and still be under the bench (not beside it).
3) Also make sure that the width of each 'leg' is of course not more then the depth of your bench or they will stick out the front.
Step 3: Attach the Bench
I used a spare piece of bench from our recent kitchen renovation. You can usually pick up some offcuts cheap or free if you ask a kitchen installer or keep an eye out around the neighbourhood for someone throwing one out. Alternatively some decent chipboard from the hardware is not expensive.
You can see below how it all went together. I used a large piece of 2x6 to hold the bench to the wall. This needs to be strong as it will bear the weight of the bench when folded down. Also a good idea to attach it firmly. This one is attached to studs in the wall behind the plywood.
Same goes for the legs - make sure they're firmly attached. These are also screwed into a stud inside the wall.
You can see where I skew nailed the rear of the legs in this picture.
I used gate hinges as this will spend most of it's life hanging down and I want it to be well supported. Perhaps this was overkill...
This is the completed product. In my case the width apart that I positioned the legs was determined by the location of the wall studs.
I might add some 'tabs' to the side of the bench at the front in the future just to make sure the legs don't splay out and allow the bench to drop, but they're pretty solid for now and don't move.
All in all this project cost me about £15 as I already had the benchtop. Even if you purchased this I can't see it costing you more than £50 for the entire thing.