A Japanese kotatsu is a short table that is used as a warm spot to work or do tabletop activities. It is heated from below with a heat source and insulated with a blanket. A kotatsu is a little lower than the height of a coffee table, so it can be made from one by shortening the legs, adding a heat source, attaching a quilt and attaching an additional table top. A kotatsu can be useful for working at home during cold weather.
Cut the legs of the coffee table so that it ends up at a comfortable height for you to work at while sitting on the floor.
Measure the dimensions of the top of the coffee table and cut your plywood so that it is the same length and width. Sand the plywood and stain or paint it. This will be your table top, so use a colour that you want to show.
Centre the quilt on the top of the coffee table. Staple the quilt to the top of the coffee table along the edges and in the centre to keep it in place.
Turn the table upside down and mount the kotatsu heater at the centre of the table, according to the instructions included with the heater. Turn the table right side up.
Place the painted or stained plywood on top of the coffee table. Drill a hole in each corner at about 5 cm (2 inches) from the point as a guide hole for the screws. Screw them into the holes to secure it to the coffee table through the fabric of the quilt. Alternatively, you can use a nail gun and nails to secure the plywood to the table instead of using screws.
There are safe heaters specifically made for use with a kotatsu; these heaters are available online. If you would like to see the fabric of the quilt through the tabletop, you can use plexi-glass instead of wood for the top of the kotatsu.
Do not use regular space heaters to heat your kotatsu, as they are not made for use near fabrics or in unvented spaces. Check the specifications of your heat source before purchase and installation to ensure safety. Follow all manufacturers guidelines for the heat source. Be sure to unplug the heater for your kotatsu when it is not in use to prevent overheating and fire.