NBC 202: Mandatory Rules of Thumb for Load Bearing Masonry (48 pages) gives simple, field-ready rules for building earthquake-safer load-bearing brick or stone buildings up to two storeys plus an attic — without full structural calculation. It is the most-used NBC document for small residential buildings in Nepal.
Wall Thickness and Height Limits
Load-bearing masonry walls must be at least half-brick thick (110 mm) and not more than one brick thick (230 mm). Storey heights and total building height are limited so walls stay stable under lateral loads — taller or heavier buildings need engineered design instead of rules of thumb.
Seismic Bands — the Most Important Rule
Provide continuous horizontal seismic bands at plinth, sill, lintel, and roof levels. A band consists of two (or four) longitudinal steel bars with stirrups, embedded in 75 mm (or 150 mm for wider walls) thick concrete, running unbroken around the entire building. Bands tie the walls together so the building acts as one box during shaking.
Openings: Size and Location
Keep door and window openings small and well-spaced. Openings must be located away from inside corners by a clear distance of at least one-quarter of the opening height, but not less than 600 mm. The total length of openings in a wall is limited as a proportion of wall length — too much opening weakens the wall.
Key Rules for Site Engineers
- Use rich cement-sand mortar (1:4 or richer) for load-bearing walls; weak mud mortar is not permitted for these rules.
- Provide vertical steel bars at corners, junctions, and beside large openings, anchored into the bands and foundation.
- Limit the unsupported length of walls; add cross-walls or piers where walls run long.
- Keep the building plan compact and symmetric — avoid re-entrant corners and large projections.
- Anchor the roof/floor to the walls so diaphragm action transfers lateral loads to the walls.
Summary for working engineers. For the full legal requirements, always refer to the official NBC 202 document published by the Government of Nepal.
Hosted copy of the DUDBC publication.
Published by the Government of Nepal (DUDBC).