Flat 4 3, 20 Gillingham Street, Westminster, London, SW1V 1AG

Flat 4 3 is a two-bedroom mid-terrace house in Westminster, London, London (SW1V 1AG). It has a recorded floor area of 52 m² (around 560 sq ft), construction records dating it to 2007 onwards and council tax band F. At 52 m² this is the smallest unit on EPC record across the building (52–69 m²). The building's EPC ratings span C to B, with this unit at the top. The latest certificate (October 2018) returns a B (score 82), comfortably above the UK average. The rating has held steady at B across 2 certificates since March 2009. Between certificates, hot-water efficiency dropped from Very Good to Good and main heating dropped from Very Good to Good.

Held since September 2009 — that's 17 years off the open market, well above the local norm. That sale fell during the post-crash dip, which often skews comparisons against later neighbouring sales. At 52 m² it's 15.5% smaller than the typical home in the postcode (62 m² median across 36 EPCs).