▁by ▁K ul ka ▁and ▁described ▁in ▁K ul ka ' s ▁words ; ▁ ▁“ The ▁rooms ▁of ▁his ▁houses ▁are ▁situated ▁on ▁various ▁levels , ▁inter - related ▁in ▁harm on ious ▁proport ions , ▁space ▁flow ing ▁into ▁space , ▁but ▁forming ▁a ▁compact ▁unit . ▁The ▁levels ▁are ▁not ▁bound ▁to ▁a ▁special ▁floor ▁( ground ▁floor , ▁first ▁floor , ▁etc .) ▁and ▁are ▁not ▁the ▁result ▁simply ▁div iding ▁a ▁high ▁room ▁into ▁me zz an ine ▁parts . ▁The ▁flo ors ▁are ▁inter - related ▁rooms ▁with ▁open ▁v istas , ▁the ▁levels ▁connected ▁by ▁steps ” ▁ ▁As ▁K ul ka ▁had ▁an ▁aff inity ▁for ▁Lo os ' s ▁thinking ▁and ▁had ▁an ▁apt itude ▁to ▁three ▁dimensional ▁planning , ▁he ▁became ▁Lo os ' s ▁assistant ▁and ▁later ▁became ▁his ▁partner , ▁further ▁developing ▁the ▁Raum plan ▁concept . ▁ ▁In ▁ 1 9 2 2 ▁K ul ka ▁assist ed ▁Lo os ▁on ▁the ▁real isation ▁of ▁the ▁first ▁cub ic ▁Raum plan ▁house , ▁the ▁Villa ▁Ru fer ▁in ▁H iet zing ▁Vienna . ▁ ▁Between ▁ 1 9 2 2 ▁and ▁ 1 9 2 3 ▁K ul ka ▁designed , ▁autonom ously , ▁a ▁cub ic ▁Raum plan ▁in ▁smaller ▁cub ic ▁dimensions ▁than ▁the ▁Villa ▁Ru fer . ▁K ul ka ' s ▁autonom ously ▁designed ▁prototype ▁became ▁subsequently ▁known ▁as ▁the ▁Cub ic , ▁D ice ▁or ▁Wür fel haus , ▁and ▁was ▁real ised ▁in ▁Vienna