Each of the six rooms measures just one pyoung, a traditional unit of measurement in Korean architecture. That’s about 4 square yards, or as Cho puts it, just enough to “lie down and still have a few inches of space.” Photo 8 of 13 in Underground House in Seoul by Winifred Bird

Underground House in Seoul

8 of 13

Each of the six rooms measures just one pyoung, a traditional unit of measurement in Korean architecture. That’s about 4 square yards, or as Cho puts it, just enough to “lie down and still have a few inches of space.”