Worked Example: Full Substructure Takeoff of a 2BHK

This is the lesson where the module keeps its promise. Below is a complete substructure takeoff of a small house — every item, every working shown, ending in a quantity sheet with indicative rupee values. Work through it once following the text, then a second time with a calculator and a blank sheet, checking each line. When your sheet matches, you can measure the below-plinth work of any wall-type building in India. Where your own project differs — an RCC frame, stone masonry, a raft — the items change but the discipline is identical: one length statement, layer by layer, derived quantities on paper, everything signed before it is buried.

The building and the assumptions

A single-storey 2BHK, 9.00 m × 12.00 m out-to-out (plinth area 108 m² = 1,163 sqft). Assumptions, stated up front the way every defensible estimate must:

• Load-bearing construction, all walls 230 mm modular brick in CM 1:6. (An RCC-framed version would swap lessons 3's isolated-footing takeoff into this sheet; everything else survives.)
• Internal layout: one full cross wall P at 7.50 m from the west wall; wall S dividing the west zone into living/dining and kitchen; wall Q dividing the east zone into two bedrooms. Light 115 mm partitions (bath, wardrobe niches) sit on the floor slab and are excluded from the foundation takeoff.
• Firm murrum-type soil, safe bearing assumed adequate at 1.05 m founding depth (get this confirmed for a real site — soil report or local engineer, not hope). Water table well below founding level. Not black cotton soil.
• Strip foundation, one section throughout: trench 900 wide × 1,050 deep; PCC 1:4:8 900 × 150; brick footing steps 690 × 400 and 460 × 500 (0.15 + 0.40 + 0.50 = 1.05 m — the masonry tops out exactly at ground level); plinth wall 230 × 600 to plinth level.
• DPC 40 mm CC 1:2:4 with waterproofing compound; anti-termite treatment per IS 6313 (Part 2); plinth build-up 250 fill + 230 rubble soling + 75 floor-bed PCC + 45 finish.
• Doors: main 1.0 m plus four internal 0.9 m openings crossing 230 walls.

Step 1 — the centre-line statement

Effective length per layer = 61.63 − 6 × (b/2):

This half-page is the spine of the whole takeoff — and the sheet you get signed before excavation starts.

Step 2 — earthwork

• Excavation = 58.93 × 0.90 × 1.05 = 55.69 m³ (= 1,966 cft ≈ 19.7 brass). Depth 1.05 m, so the whole item sits in the basic lift; soil stacked on site for reuse.

Step 3 — PCC and masonry

• PCC 1:4:8 = 58.93 × 0.90 × 0.15 = 7.96 m³. Cement at ~3.4 bags/m³ = 27 bags, sand ≈ 3.7 m³, aggregate ≈ 7.5 m³.
• Footing step 1 = 59.56 × 0.69 × 0.40 = 16.44 m³.
• Footing step 2 = 60.25 × 0.46 × 0.50 = 13.86 m³.
• Masonry below GL = 30.30 m³; plinth wall = 60.94 × 0.23 × 0.60 = 8.41 m³.
• Total brickwork = 38.71 m³ → bricks at ~500/m³ = 19,355; order about 20,000 with breakage. Mortar ≈ 9.7 m³ → cement ≈ 53 bags, sand ≈ 11 m³.

Step 4 — the derived earth items

• Backfill = 55.69 − (7.96 + 30.30) = 17.43 m³.
• Inside plinth area = 108.00 − 60.94 × 0.23 = 108.00 − 14.02 = 93.98 m².
• Plinth fill (250 mm compacted) = 93.98 × 0.25 = 23.50 m³.
• Soling (230 mm rubble) = 94.0 m² (rubble supply ≈ 22 m³ stacked, inside the rate).
• Soil balance: reuse 17.43 + 23.50 = 40.93 m³ against 55.69 m³ dug — the excavated murrum covers everything with roughly 15 m³ (bank) surplus to dispose, about six trolley trips. If your soil turns out expansive, this line flips into a purchase — reprice before the thekedar does.

Step 5 — the protective layers

Anti-termite emulsion (rates from lesson 5):

Concentrate at 1 percent from 20 EC = about 106 litres. That number is your audit weapon against any lump-sum quote.

• DPC area = 60.94 × 0.23 = 14.02 m²; deduct door sills (1.0 + 4 × 0.9 = 4.6 m) × 0.23 = 1.06 m² → 12.96 m² (≈ 0.52 m³ of concrete, 3 to 4 bags cement, ~3.5 kg compound).

The summary sheet

Indicative mid-2026 all-in item rates, rounded — replace every rate with your city's current quotations before using this as a budget:

That is roughly ₹340 per sqft of plinth area for the substructure — a useful sanity band (substructure typically lands between 12 and 20 percent of a conventional house's cost; deep foundations, rock or black cotton soil push it up). Note the sheet's units deliberately mix SI and site practice: the thekedar will read item 1 as 19.7 brass and item 3 as bricks — your conversions (1 m³ = 35.31 cft; 500 bricks/m³) bridge the two without changing a single certified number. And a RERA-era footnote: cost-per-sqft comparisons with builder quotes must state the area basis — this ₹340 is on plinth (built-up) area; RERA carpet area excludes external walls and would read misleadingly higher.

How this protects your money end to end: every number above traces to the drawing through arithmetic a stranger can check — a signed centre-line statement, derived backfill, stage-wise litres, photographed hidden work. When the first RA bill arrives claiming 70 m³ of excavation and "backfill as per excavation", you do not argue; you hand over this sheet. Documentation beats memory, in front of a thekedar, a PMC or a consumer forum alike.

Common mistakes on full takeoffs

• Losing the junction count when the plan changes — a revised kitchen wall silently changes six deductions; re-issue the centre-line statement on every drawing revision.
• Height stack not closing — PCC + steps must exactly equal founding depth; if 0.15 + 0.40 + 0.50 does not equal your trench depth, the drawing and takeoff disagree and one of them is wrong.
• Mixing gross and net plinth areas between fill (inside walls) and soling (same) versus plinth area (overall) — label each area on the sheet.
• Carrying indicative rates into a contract. The quantities column is engineering; the rate column is market. Only one of them is yours to defend.

Where this goes next

Above the DPC waits the superstructure — columns, beams, slabs, shuttering and steel — where quantities multiply and BBS discipline decides the steel bill. That is Module 3. Bring your centre-line statement; the walls above the plinth follow the same lengths you have already signed.