| 2, Castle Avenue, Northampton | - | 96 m² | - |
| 4, Castle Avenue, Northampton | Freehold | 92 m² | £202,000 (2019) |
| 6, Castle Avenue, Northampton | Freehold | 92 m² | £220,000 (2020) |
| 8, Castle Avenue, Northampton | - | 96 m² | - |
| 12, Castle Avenue, Northampton | Freehold | 92 m² | £265,000 (2025) |
| 14 Castle Avenue, Northampton | Freehold | 107 m² | £200,000 (2021) |
| 16, Castle Avenue, Northampton | - | 92 m² | - |
| 18 Castle Avenue, Northampton | Freehold | 75 m² | £240,000 (2025) |
| 20, Castle Avenue, Northampton | Freehold | 85 m² | £100,000 (2002) |
| 30 Castle Avenue, Northampton | - | 80 m² | - |
| 32 Castle Avenue, Northampton | - | 96 m² | - |
| 36, Castle Avenue, Northampton | Freehold | 100 m² | £140,000 (2006) |
| 38, Castle Avenue, Northampton | Freehold | 62 m² | £170,000 (2015) |
| 42, Castle Avenue, Northampton | Freehold | 78 m² | £200,000 (2018) |
| 44 Castle Avenue, Northampton | Freehold | 96 m² | £255,000 (2025) |
| 46, Castle Avenue, Northampton | Freehold | 114 m² | £320,000 (2026) |
| 48, Castle Avenue, Northampton | - | 90 m² | - |
| 50, Castle Avenue, Northampton | Freehold | 83 m² | £82,500 (2012) |
| 52 Castle Avenue, Northampton, Northampton | - | 67 m² | - |
| 54 Castle Avenue, Northampton, Northampton | - | 66 m² | - |
| 56, Castle Avenue, Northampton | - | 81 m² | - |
| 58 Castle Avenue, Northampton | Freehold | 79 m² | £175,000 (2026) |
| 60 Castle Avenue, Northampton | - | 80 m² | - |
| 62, Castle Avenue, Northampton | - | 92 m² | - |
| 66, Castle Avenue, Northampton | - | 79 m² | - |
| 68 Castle Avenue, Northampton | Freehold | 141 m² | £332,000 (2025) |
| 70, Castle Avenue, Northampton | Freehold | 99 m² | £149,000 (2006) |
| 72, Castle Avenue, Northampton | Freehold | 98 m² | £245,000 (2021) |
