Flat 4, 173 Copnor Road, Portsmouth, PO3 5BT

Flat 4 is a one-bedroom detached house in Portsmouth (PO3 5BT). It has a recorded floor area of 30 m² (around 323 sq ft), construction records dating it to 1900-1929 and council tax band A. At 30 m² this is the smallest unit on EPC record across the building (30–64 m²). The building's EPC ratings span D to C, with this unit at the top. On EPC score it ranks first in the building (78 versus a worst of 59). The latest certificate (June 2021) shows a C (score 78), near the top of the C band. Earlier certificates rated it B (June 2010); the latest reading is one band lower. Between certificates, lighting went from Very Poor to Very Good; while hot-water efficiency dropped from Very Good to Good and main heating dropped from Very Good to Good.

Held since September 2010 — that's 16 years off the open market, well above the local norm. At 30 m² it sits well below the postcode median (67 m² across 10 EPCs), making it one of the more compact homes locally. Today's modelled estimate of £127,000 is 41.1% above the 2010 sale price. On a £-per-square-foot basis, the last sale (£279/sq ft) was about 68.7% above the typical sold price in the postcode.