👉Here’s a clear step‑by‑step explanation of how block quantity is calculated for a wall with openings like doors and windows:

🧱 Step 1: Measure Wall Dimensions

- The wall height is 2800 mm (2.8 m).
- The total wall length is the sum of left side (4.5 m), door width (0.9 m), and right side (3.6 m) = 9.0 m.
- So, gross wall area = 9 × 2.8 = 25.2 m².

🚪 Step 2: Deduct Openings

- Door area = 0.9 × 2.1 = 1.89 m².
- Window area = 1.2 × 1.2 = 1.44 m².
- Total openings = 3.33 m².
- Net wall area = 25.2 − 3.33 = 21.87 m².

📐 Step 3: Block Size

- Block size including mortar joint = 475 mm × 250 mm = 0.475 × 0.25 m = 0.11875 m² per block.

🔢 Step 4: Calculate Number of Blocks

- Net wall area ÷ Block area = 21.87 ÷ 0.11875 ≈ 184 blocks.
- This gives the total number of blocks required for construction.

✅ Summary

1. Find gross wall area.
2. Deduct door and window openings.
3. Calculate net wall area.
4. Divide by block area to get block quantity.

@etconp