11a, Effingham Road, Long Ditton, Surbiton, KT6 5JZ

11a is a one-bedroom semi-detached house in Long Ditton, Surbiton, Surbiton (KT6 5JZ). It has a recorded floor area of 72 m² (around 775 sq ft), construction records dating it to 1900-1929 and council tax band C. The latest certificate (August 2018) shows a D (score 68), on the cusp of jumping into the C band. When first surveyed in October 2008 the rating was E, the property has climbed 1 band since. Between certificates, window efficiency went from Very Poor to Good and lighting went from Good to Very Good. The recommended improvements would push it to C (score 77). At 72 m² this is the 16th smallest of 31 units on EPC record in the building, where floor areas span 31–240 m². The building's EPC ratings span F to C across 31 units on file.

It hasn't traded since March 2004, a hold of 22 years that's notably long for the area. Across 1999–2004, sale prices on this property compounded at 17% per year. Today's modelled estimate of £376,000 sits 92.8% above the 2004 sale of £195,000. On a £-per-square-foot basis, the last sale (£252/sq ft) was about 19% below the postcode norm.