This costume only took me 2 days to make and another day to paint.
I started this costume by first figuring out some proportions. This involved me looking for every picture of a Tardis from the show I could find on the internet. I came up some percentages on the width of the Tardis, and from there made up my own numbers to build it to the size I wanted. The main body of the Tardis should be about 75% or your planned width with each corner panel being about 12.5% of the width. See my diagram for details.
Step 1: Materials needed / getting started
You will also need:
-Carpenters glue (white glue doesn’t dry fast enough or is strong enough)
-Four 1x1 strips of wood
-Four 1x1/2 strips of wood
I made a box with the 1/2 inch strips and then used the 1x1's to create the 'legs'. I made this simple frame so that I would have something to attach all the cardboard to.
Sorry about switching units of measure, but to calculate my sizes and proportions quickly I switched to metric.
I based the size of the Tardis on my son. In my case the top square was 64 cm by 64 cm and I made it 103.5 cm tall.