At the turn of the century, there was a move away from the huge, monolithic style of building (which was epitomised by the asylum architecture at the time) towards a more human scale; wards were separated into separate villas and scattered around the site to approximate a normal housing layout. Main halls, chapels and other shared facilities became stand-alone structures. Huge boiler houses and laundries were tucked out of sight on the edge of the complex, feeding buildings via underground steam pipes.

Leybourne Grange is a perfect example of this architectural style, the villas arranged in huge sweeping loops, each loop comprising its own community (and perhaps style of patient). Lessons were still borrowed from the older asylums: the wards may now be separate but the day-rooms still all faced south, or south east.