Flat 2, 51 Semilong Road, Northampton, NN2 6BT

Flat 2 is a one-bedroom mid-terrace house in Northampton (NN2 6BT). It has a recorded floor area of 40 m² (around 431 sq ft), construction records dating it to 1900-1929 and council tax band A. At 40 m² this is the smallest unit on EPC record across the building (40–80 m²). The building's EPC ratings span E to D, with this unit at the top. On EPC score it ranks first in the building (66 versus a worst of 45). The latest certificate (March 2020) shows a D (score 66), on the cusp of jumping into the C band. When first surveyed in January 2009 the rating was E, the property has climbed 1 band since. Between certificates, wall efficiency went from Very Poor to Poor, window efficiency went from Very Poor to Good and hot-water efficiency went from Very Poor to Poor; while main heating dropped from Poor to Very Poor. The recommended improvements would lift it to B (score 84), a 2-band jump. Main heating runs on electricity.

Untraded for 27 years, with the last transfer in October 1999. Across 1995–1999, sale prices on this property compounded at 3.3% per year. Today's modelled estimate of £112,000 sits 286.2% above the 1999 sale of £29,000. On a £-per-square-foot basis, the last sale (£67/sq ft) was about 47.1% below the postcode norm.