17a, Stocklake, Aylesbury, HP20 1DN

17a is a one-bedroom end-of-terrace house in Aylesbury (HP20 1DN). It has a recorded floor area of 45 m² (around 484 sq ft), construction records dating it to 1900-1929 and council tax band A. At 45 m² this is the 2nd smallest of 18 units on EPC record in the building, where floor areas span 38–112 m². The building's EPC ratings span F to C, with this unit at the top. On EPC score it ranks first in the building (69 versus a worst of 36). The latest certificate (March 2021) shows a C (score 69), just inside the C band. When first surveyed in March 2009 the rating was D, the property has climbed 1 band since. Between certificates, window efficiency went from Very Poor to Average and lighting went from Poor to Very Good; while hot-water efficiency dropped from Very Good to Good and main heating dropped from Very Good to Good.

Held since January 2007 — that's 19 years off the open market, well above the local norm. That sale landed at the peak of the pre-credit-crunch market, which is a useful reference point when interpreting the price. At 45 m² it sits well below the postcode median (91 m² across 17 EPCs), making it one of the more compact homes locally. On energy efficiency it sits in the top 10% of properties in this postcode. Today's modelled estimate of £171,000 is 36.8% above the 2007 sale price. On a £-per-square-foot basis, the last sale (£258/sq ft) was about 40.1% above the typical sold price in the postcode.