Old Thomas's House is a special building. It is unlocked upon completing the Magnifying Matrix quest.
It requires 5 Wooden Beams, 5 Stone Blocks, 5 Simple Glues and 1 Magnifying Matrix to build. It drops 150 Coins every 2 hours. It may also randomly drop Spellbooks used to upgrade Wizard Schools.
Building Old Thomas's House completes the A House For Old Thomas Quest and signals the end of the Old Thomas Introduction Questline.