A small deck with over sized furniture required an undersized coffee table. The intent was to get lumber as close to size as possible and essentially build the table by assembling standard dimensional lumber pieces. Much of the design happened on-the-fly while browsing the "stock" wood sizes in the lumber isle. The only thing I new for certain at the outset was that the table top dimensions had to be no larger than 48" x 16". The rest fell into place from there.

The construction result was a coffee/planter/beverage table. It fits the space, it's great having somewhere to place your coffee or beverage, and staring at the plants growing out of the table induces a state of zen-like calm. When the sun goes down, the planter can be removed and filled with one containing ice and beverages to toast the end of another glorious day on planet earth. In winter, the lid covers the opening, waiting for the next spring and the opportunity to create a different look for the new season.

Step 1: The Gathering

The supplies for this project all fit into small SUV or hatchback with folding seats. I'm pretty sure you could use a bicycle as well but that would be beyond my abilities. Dimensions below are all in English/Imperial units because everything you buy in the USA is supplied that way. Attempts at metrication are sporadic and for the most part still a failure.

Nothing on this list should be taken as prescriptive. Use whatever you are comfortable with.

Wood

Table top - 4ft x 16" x 0.75"
Table Legs - 8ft x 4"x4" pine or redwood post. If this is not available, you can laminate 2x4 together to make a 4"x4" table leg.
Side and Front Apron - 1"x3"x8ft x Actual board width is 2.5" - dimensional lumber in this country is supplied thinner than claim due to lumber being sized prior to processing. Final drying and planing produces boards that are thinner and narrower. All this means that when you go shopping for wood, requesting a 1"x3" will result in you getting a 0.75"x2.5" board. But, things appear to be changing. I noticed that the barcode label had the actual final dimensions after processing. I highly doubt this will change for construction lumber, but for hobby and furniture lumber, knowing the actual dimensions is helpful.
Planter support - 1"x2"x6ft (actual 0.75"x1.5"x6ft)

Other supplies

Planter box - Standard, off the shelf 11 quart plastic planter box available at any nursery. 11 quart is 10.4 liters. Dimensionally the planter I used is 23.5"(L) x 7.75"(W) X 6"(D)
Wood glue - outdoor waterproof
Deck stain - needs to protect the wood against the elements. Deck stain is a convenient way to achieve this protection. Any outdoor rated stain and polyurethane combination will be fine.
Pocket screws

Tools

Power Miter saw or hand saw with miter box. Power tools make the work go faster and when you have a lot of projects, getting something done faster is key to getting more done!
Pocket hole jig - I bought a Kreg jig many years ago and I'm still using it. I have lost count of the number of projects I have used it on and the drill bit still cuts just fine.
Drill and drill bit assortment
Measuring tape or ruler
Nail gun with brad nails or a hammer and nails if you have a lot of time on your hands! I find a nail gun to be a great work accelerator allowing more time for other projects.
Clamps for holding pieces together for gluing and nailing.
Circular saw or Jig saw for cutting out the hole in the table top

Step 2: Frame Construction

The planter table is supported on 4"x4" redwood legs. These are cut down to size on the miter saw to a final length of 18". The rails fit between the legs so there is a bit of measuring and compensation for non-exact wood dimensions. The 4"x4" post is closer to 3.5" x 3.5". The easiest thing to do is to use the table top as a work surface and then place the 4 legs on each corner. Then use a scrap of the wood, 0.75" thick to space the legs in toward the center by 0.75" all around. Then measure the lengths of the rails you need.

In my case the rails measured 39.5" long. It doesn't matter if you are a little off here - just cut both rails to the same length.

The side apron pieces measure 7.5" long. Technically this means that if you measure twice and cut once, you can get all of the apron pieces out of a single 8ft long 1"x3" board... and still have a small scrap piece left over. Practically, I screwed my first cut up and had to cut a second board. This is normal for me. Even when I measure, what I see on the tape measure is sometimes different to the actual measurement I need and my brain will not alert me to this fact.

Drill pocket holes in the ends as shown and assemble the frame using the table top as an alignment surface.

Step 3: Preparing the Table Top

With the frame constructed and out of the way, the table top can be constructed. I created a skirt (not sure what the correct technical term is) around the perimeter of the table top to add thickness. With the chunky legs, I felt that the table top needed to be thicker to create the correct proportions.

I mitered the corners as you can see from the pictures to hide the end grain. In hindsight, this was not necessary since the table top end grain is exposed anyway and the deck stain does a great job of covering it up.

Step 4: Fixing the Gap

A trail attachment of the legs to the table top showed a void underneath the legs. This was quickly fixed by cutting four square 2.5" pieces and gluing/nailing them into each corner to fill in the gap.

Step 5: Mounting the Planter

The cutout of the planter was made so that the lid could be used as a a cover in winter. The top of the plastic planter box is not exactly level, so resting the lid on this will create an uneven table surface when the planter is removed in winter. The opening was cut larger so that a ledge could be created for the lid which would allow the lid to be flush with the table top, and then the planter was recessed below this ledge.

I used a circular saw to cut the opening, and then a jig saw to get all the way into the corners. With the lid removed, a frame was constructed on the underside that would support the lid. The planter must be able to slide through this frame. As luck would have it, a standard 1.5" wide length of wood fit perfectly and was glued and nailed around the periphery of the hole.

A second frame is then constructed to create a ledge for the planter box. This is best done with the planter box in place and measuring and adjusting as you go. All you want is a ledge for the planter to rest on.

Step 6: Staining and Final Assembly

Assembly is simply a case of screwing the table top to the frame. I used pocket holes in the apron to screw up from the under side to keep the fasteners hidden. There are many ways to do this - I have no preference for any particular method. I used deck stain to stain the assembled table. This will hopefully protect the wood from rain and provide many years of service.