| 1A, Hartlea Avenue, Darlington | Freehold | 92 m² | £190,000 (2022) |
| 2, Hartlea Avenue, Darlington | Freehold | 69 m² | £172,000 (2004) |
| 3, Hartlea Avenue, Darlington | Freehold | 119 m² | £170,000 (2016) |
| 5 Hartlea Avenue, Beaumont Hill, Darlington, Darlington | Freehold | 112 m² | £299,950 (2021) |
| 6, Hartlea Avenue, Darlington | Freehold | 115 m² | £205,000 (2017) |
| 7 Hartlea Avenue, Darlington | Freehold | 108 m² | £245,000 (2025) |
| 8, Hartlea Avenue, Darlington | Freehold | 101 m² | £176,000 (2013) |
| 9, Hartlea Avenue, Darlington | - | 92 m² | - |
| 10, Hartlea Avenue, Darlington | - | 111 m² | - |
| 11, Hartlea Avenue, Darlington | Freehold | 79 m² | £168,000 (2017) |
| 12, Hartlea Avenue, Darlington | Freehold | 163 m² | £240,000 (2021) |
| 15, Hartlea Avenue, Darlington | Freehold | 79 m² | £152,500 (2013) |
| 18, Hartlea Avenue, Darlington | Freehold | 125 m² | £220,000 (2019) |
| 19, Hartlea Avenue, Darlington | Freehold | 109 m² | £158,500 (2018) |
| 20, Hartlea Avenue, Darlington | Freehold | 90 m² | £157,000 (2007) |
| 21, Hartlea Avenue, Darlington | Freehold | 76 m² | £122,500 (2020) |
| 25 Hartlea Avenue, Darlington | - | 81 m² | - |
| 31, Hartlea Avenue, Darlington | - | 81 m² | - |
| Burbank, Hartlea Avenue, Darlington | - | 154 m² | - |
| Corbiere, Hartlea Avenue, Darlington | Freehold | 85 m² | £210,000 (2019) |
| Jareck, Hartlea Avenue, Darlington | Freehold | 225 m² | £206,000 (2012) |
| Lynter, Hartlea Avenue, Darlington | Freehold | 128 m² | £150,000 (2020) |
| Thirdown, Hartlea Avenue, Darlington | Freehold | 99 m² | £275,000 (2022) |