| Abbreviation | Definition |
|---|---|
| NTAH | Normal Tissue Architecture and Hepatocytes |
| NTS | Not To Scale |
| NUMA | Non Uniform Memory Architecture |
| NWSA | North Wales Society of Architects |
| NZE | Net Zero Energy |
| NZEB | Nearly Zero Emission Building |
| NZIA | New Zealand Institute of Architects |
| OA | Open Architecture |
| OA | Operational Architecture |
| OAAT | Open Architecture Assessment Tool |
| OAB | Office of Architecture in Barcelona |
| OAB | OGC Architecture Board |
| OACD | Open Architecture Curricular Design |
| OACE | Open Architecture Computing Environment |
| OACIS | Open Architecture Clinical Information System |
| OACM | Owner Architect Construction Manager |
| OAD | Office of Architecture and Design |
| OADG | Open Architecture Developers' Group |
| OAET | Open Architecture Enterprise Team |
| OAH | Overall Height |