As you can imagine, it is not easy to find such specific furnishings, and though my set designer hunted high and low for couches to rent, borrow, or otherwise acquire, nothing came through. So we decided, just over a week before the show, that we would build them ourselves.
These three couches were built in two days, and are a creative work completed by many members of our cast and crew, though I think only grossmr1 and I are on Instructables.
We were in something of a hurry, so I didn't get a chance to photograph a step-by-step, but hopefully you can learn something from the pieces I can document.
(Theatrical photos courtesy of johnnyman727.)
Foam padding for seat cushion: 2" thick, cut to sheets of 2"x4.5"; one for each of the seat cusions, one for the back of the blue couch, and scraps for the back of the red (something like this)
Quilt batting: 1 roll of medium-density batting for a full-size quilt per armrest (something like this, I think)
Upholstery fabric: 3 1/3 yards of green, 3 3/4 yards of red, 4 3/4 yards of blue*
Decorative trim: 5 yards for each of the green and red couches, 7.5 yards for the blue couch (like this)
Needle & thread
*Note: we used a very thick, almost suede-like fabric for the blue. This was very difficult to sew and is not recommended, but it did look cool. Definitely use a heavy needle if you choose heavy fabric.
MDF (for seat)
Moulding to cover fronts of armrests (like this)
Decorative accents (like this and this and this and this- go wild)
Gold spray paint
Dowels for armrests
Screws of varying lengths
Make a rectangle out of the 1x4s.
Attach legs at corners (also 1x4s): make them high enough to reach the center of the armrest, or higher for a backed sofa
Cut and attach MDF to top.
Attach an extra 1x4 to the front bottom edge of each couch (decorative)
Attach false legs as desired (the middle legs on the blue and green couches are decorative).
For the blue couch, attach a crossbeam for the back. (This is the only structural component of the back.)
Cut molding so that it will cover the fronts of the legs.
Spray paint decorative accents gold.
Cut foam pads to bench size (20" x 4.5'). Sew covers onto them.
Sew on skirt flaps around each side of the foam pads. Leave spaces where the legs will be.
Sew cylindrical tubes the size you want your armrests. Leave approximately 8" of extra fabric at each end (as the diameter of your armrests should be something like 8"-9").
Unroll quilt batting and reshape to 20" wide (our started out at 17" wide). Cut off any excess from reshaping that does not fit within the width you want. Staple a 20" dowel to the end of the batting and re-roll the batting tightly with the dowel in the center. Stuff into cylindrical fabric tubes. Tuck in fabric ends.
For red couch, cut whimsically shaped foam. Sew cover to match, leaving a sleeve for the frame to fit on.
Bring it together
Place seat cushions on benches. Tack on with staple gun.
For the blue couch, cut a hole in the foam where the arm dowels go and staple into position.
For the red couch, slide back into position. Cut additional pieces of 1x4 to support the ends of the foam design and screw them into the back of the couch.
Sew on decorative trim by hand to cover staples.
Fit armrests into place (you should have one extra- one of the red ones is just a pillow). Screw through legs into armrests.
Smear liquid nails on the back of the stained molding and place it on the couch. Hold in place with finishing nails.
Repeat above process with gold-painted accents, particularly placing over any ugly places e.g. where false legs meet frame and the ends of the red pillow.
Break a leg!
But don't break a couch. These things are pretty solid.