| Abbreviation | Definition |
|---|---|
| NPCP | National Photovoltaic Construction Partnership |
| NPDES | National Pollution Discharge Elimination System |
| NPS | Non-Point Source |
| NPSF | National Pipe Straight Fuel |
| NPT | National Pipe Taper (thread); (cf. NPS) |
| NRBR | Northern Rivers Bathroom Renovations |
| NRC | National Research Council |
| NRC | National Response Center |
| NRC | New Residential Construction |
| NRCA | National Roofing Contractors Association |
| NRCMA | National Railroad Construction Maintenance Association |
| NRCS | Natural Resources Conservation Service |
| NRP | Nonrigid Pavement |
| NSF | National Science Foundation |
| NSFD | New Single Family Dwelling |
| NSS | Non-Skid Surfacing |
| NUC | Neutral Unit of Construction |
| NURP | National Urban Runoff Program |
| NVSD | Non-Vibration Sand Drain |
| NW | Northwest |