Just interesting to note four different writing systems used in four characters on each pillar. "1F" combines arabic numerals and roman letters to indicate the first floor. The house is divided into a grid where Chinese numbers indicate the position from north to south, and Japanese hiragana indicate the position east to west. For the carpenter, the zero point is the north-east corner. The architect, on the other hand, starts with X0 and Y0 in the bottom left hand corner of the drawing: the south-west corner.
The order of the hiragana is not the phonetic order usually used in teaching (a i u e o ka ki ku ke ko...あいうえおかきくけこ) but the older order, i-ro-ha order (i ro ha ni ho he to chi ri nu wo... いろはにほへとちりぬを). This order came from a poem written around a thousand years ago, that contained each syllable only once. Read more on wikipedia. they changed to the new order, based on Sanskrit, apparently, in the Meiji reforms in the latter 19th century. Iroha is still alive and well in house building.
