Structural Design, Drafting ,BBS and Estimation of Building (357.0 sq.m)
Staff Quarter · BBS & Estimation 357.0 m² · G+2
Er. Alish Subedi · Civil Engineer
This project presents a complete Bar Bending Schedule (BBS) and estimation for a staff quarter building (357 m²) — including foundation, columns, beams, slabs, staircase, and all finishing works. All calculations follow IS 456:2000 & SP 34, with a practical, site‑friendly approach.
The estimation process was divided into four major phases: data collection, quantity take‑off, rate analysis, and final costing. Every item was measured from architectural and structural drawings, and rates were applied from the Makwanpur district schedule.
Data & inputs
- Architectural AutoCAD drawings
- Soil investigation report
- IS 456:2000 / IS 875 (loads)
- District rate (Makwanpur) 2026
- SP 34 detailing guidelines
Quantity take‑off
- Excavation & backfill
- PCC & RCC (footing to slab)
- Brickwork (230mm & 120mm)
- Plaster, screeding, tiles
- Rebar (all diameters)
Costing & summary
- Unit rate application
- Material & labour breakup
- Sub‑structure / super‑structure split
- Verification with thumb rules
- Final BOQ & abstract
The structural design and BBS were developed simultaneously using a “draw‑first” approach in AutoCAD. This method is significantly more efficient than traditional separate calculation sheets.
Beam detailing
- Main bars (top & bottom) as per BM diagram
- Extra bars at support & mid‑span
- Stirrup spacing as per shear force
- Direct extraction from AutoCAD
Column detailing
- Main bars as per IS Codes and analysis
- Lap zone & Development length
- Lateral ties
Slab detailing
- Top & bottom reinforcement
- Extra bars at edges & openings
- Distribution bars spacing
- Cantilever slab detailing
Staircase detailing
- Waist slab main bars (M1‑M5)
- Distribution bars & steps bars
- Nosing reinforcement
- Landing & flight detailing
- Zero transcription errors – no re‑entering of lengths or quantities.
- Visual verification – bar placement is checked directly on the drawing.
- Faster revisions – any change in beam layout updates BBS automatically.
- Site‑ready output – bar schedule is directly usable for fabrication.
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