

There are different levels used in the construction, these levels are used to make the construction process easy and understandable, some of basic level as follows.
LEVELS IN CONSTRUCTION
| LEVELS IN CONSTRUCTION | |
| BOB | Bottom of Blinding |
| TOB | Top of Blinding |
| BOF | Bottom of Footing |
| TOF | Top of Footing |
| PL | Plinth Level |
| GL | Ground level |
| EGL | Excisting Ground Level |
| NGL | Natural Ground Level |
| FGL | Finished Ground Level |
| SL | Sill Level |
| LL | Lintel Level |
| SSL | Structural Slab Level / Slab Sill Level |
| FFL | Floor Finish Level / Finished Floor Level |
| SFL | Structural Floor Level / Structural Finish Level |
| FG | Finished Grade |
| FL | Finished Level |
| GF | Ground Floor |
| MF | Mezzanine Floor |
| FF | First Floor |
| SF | Second Floor |
| RF | Roof Floor |
| TOW | Top of Wall |
| BP | Bottom of Pool |
| TP | Top of Pool |
| TB | Top of Bench |
| TK | Top of Kerb |
| NC | Neck column |

The cement sand and aggregate Ratio in various concrete are grade , cement , sand , aggregate, m75 _ 1 cement _ 4 sand _ 8 aggregate. M 10 _1 cement _ sand 4 _ aggregate 8 M 15 _ 1 cement _ 2 sand _ 4 aggregate M20 1 cement _ 1, 5 sand aggregate 3 m25._ 1 cement _ 1sand _ 2 aggregate ,m30 _ 1 cement _ 1 sand _ 1 aggregate
Very Good Article
NGL means Natural Ground Level
Hi sir