255a, Ground Floor Flat, Chiswick High Road, London, W4 4PU

255a is a mid-terrace house in London (W4 4PU). It has a recorded floor area of 62 m² (around 667 sq ft) and construction records dating it to before 1900. At 62 m² this is the largest unit on EPC record across 255a (55–62 m²). The building's EPC ratings span F to D across 3 units on file. The latest certificate (May 2017) shows an E (score 54), well below the UK norm with real room to improve. When first surveyed in January 2009 the rating was F, the property has climbed 1 band since. Between certificates, wall efficiency went from Very Poor to Poor, roof efficiency went from Very Poor to Average and window efficiency went from Very Poor to Good; while hot-water efficiency dropped from Average to Poor. The recommended improvements would lift it to C (score 77), a 2-band jump.

At 62 m² the property is well over the postcode median (44 m² across 15 EPCs), placing it in the larger end of the local stock. It lags the bulk of the postcode on energy efficiency (less efficient than 87% of similar EPCs).