124a, Flat 4, Westmount Road, Greenwich, London, SE9 1UT

124a is a semi-detached house in Greenwich, London, London (SE9 1UT). It has a recorded floor area of 35 m² (around 377 sq ft) and construction records dating it to 1900-1929. At 35 m² this is the 4th smallest of 5 units on EPC record in 124a, where floor areas span 15–35 m². The building's EPC ratings span E to C, with this unit at the bottom. On EPC score it ranks last in the building (52 versus a best of 73). The latest certificate (December 2016) shows an E (score 52), well below the UK norm with real room to improve. The rating has held steady at E across 3 certificates since October 2013. Between certificates, wall efficiency went from Very Poor to Good, roof efficiency went from Average to Good and window efficiency went from Average to Good; while hot-water efficiency dropped from Poor to Very Poor and main heating dropped from Good to Very Poor. The recommended improvements would lift it to C (score 74), a 2-band jump. Main heating runs on electricity.

Across 2001–2014, sale prices on this property compounded at 3.5% per year. Today's modelled estimate of £221,000 sits 76.8% above the 2014 sale of £125,000. On a £-per-square-foot basis, the last sale (£332/sq ft) was about 67.4% above the typical sold price in the postcode. It lags the bulk of the postcode on energy efficiency (less efficient than 82% of similar EPCs). On the market in October 2014 and unlisted since — roughly 12 years.