Adequate setbacks from civil engineering structures that can pose harm to inhabitants of a residential building structure are very important to be strictly followed when erecting such structures to avoid fatalities that would follow in the case of accidents or other natural effects. When proper setbacks are followed, it could be possible for inhabitants to escape before harmful events reach such structures. Provided below are the required setbacks applicable in Nigeria.
The minimum distance a building should be away from the road to avoid demolition:
- Federal Highway (Primary) – 90 m right of way. 45 m from the centre to the property line (75 ft, 60 ft)
- State Highway (Secondary) – 60 m right of way. 30 m from the centre to the property line (50 ft, 45ft)
- Local Road (State) – 24 m, 18 m, 15 m, 12 m, 9 m, 7.5 m, and 6 m right of way respectively from the centre to the property line as applicable (31 ft, 25 ft).
- Access Road/ Street – 9 m, 6 m, from the edges.
- Building line of property and outer edge of NNPC oil pipeline – 15 m.
Required Setbacks from Different Water Bodies:
- Ocean and Seas – 150 m.
- Lagoon – 50 m.
- River – 15 m.
- Seasonal – 15 m.
- Gorges (New and Built-up areas) – 10 m.
Required Setbacks from Railway Line:
- Manned railway line – 21 m.
- Unmanned railway line – 60 m.
Required Setbacks from Different Power Lines:
- 11 KVA powerline – 6 m.
- 33 KVA powerline – (9 – 11 m).
- Substation – 12 m.
- 132 KVA powerline – (15 – 30 m).
- 330 KVA powerline – (25 – 50 m).
Technical Requirements for Setbacks for Residential Buildings:
- Standard – 6 m.
- Substandard – 9 m.
- Others – As specified by approved order for such scheme or area.
Airspaces for Residential Buildings:
- Standard – 3 m on both sides.
- Substandard – 1.5 m on one side.
- Others – 3 m between main buildings, Boys Quarters, and 4.5 m in special areas. 6 m between buildings of two (2) floors and above.
Rear Airspace:
- Standard – 3 m.
- Substandard – 1.5 m.
- Others – 4.5 m if height is up to four (4) floors.
Setback Standard for Congested Areas:
- The minimum distance to be maintained between a proposed building/extension and the front boundary of the lot to which such building relates shall be determined by the existing building line of permanent structures along such street/ road.
- The distance between the proposed building/extension and the side boundary of a lot to which it relates shall not be less than 0.8 m for lots with a frontage of 12 m or less, and 0.9 m for lots with a frontage of more than 12 m.
- The distance between a proposed building/extension and the back boundary of the lot to which it relates shall not be less than:
- 1.65 m in the case of single and two-floor single and two-family residential or residential/commercial buildings
- 2.25 m in the case of multi-family one and two-storey residential or residential/commercial buildings, and three or more-storey residential or residential/commercial buildings.
- 1.2 m in the case of one and two-storey (commercial buildings).
- 1.8 m in the case of three or more storey (commercial buildings).