Houselisting Block (HLB) UPSC relevant
The houselisting block is the smallest operational unit of Phase 1 — the patch of territory assigned to one enumerator for houselisting, demarcated so the whole country is covered without omission or duplication and workloads stay even.
Historically blocks have been sized at roughly 100–150 households (about 650–800 persons), though exact norms vary between censuses and between rural and urban areas. Census 2027 transforms how blocks are made: instead of hand-drawn notional maps, Charge Officers digitally delineate geo-referenced HLBs on satellite imagery using the Houselisting Block Creator (HLBC) web application. The same territory logic carries into Phase 2, where the units are called enumeration blocks.
Block-level geography is also what self-enumeration house-location marking feeds into — a wrongly placed map marker can put a household in the wrong enumerator's app.