39b, Horsell Road, London, N5 1XL

39b is an end-of-terrace house in London (N5 1XL). It has a recorded floor area of 66 m² (around 714 sq ft) and construction records dating it to before 1900. The latest certificate (December 2010) shows an F (score 35), near the bottom of the EPC scale. Main heating runs on electricity. The latest certificate is from December 2010, so improvements made since then won't be reflected. At 66 m² this is the 7th smallest of 15 units on EPC record in the building, where floor areas span 35–106 m². The building's EPC ratings span F to C, with this unit at the bottom. On EPC score it ranks last in the building (35 versus a best of 77).

Untraded for 19 years, with the last transfer in September 2007. That sale landed at the peak of the pre-credit-crunch market, which is a useful reference point when interpreting the price. On energy efficiency it sits in the bottom 10% of properties in this postcode — significant headroom for improvement. Across 2004–2007, sale prices on this property compounded at 16.6% per year. Today's modelled estimate of £509,000 sits 61.6% above the 2007 sale of £315,000. On a £-per-square-foot basis, the last sale (£441/sq ft) was about 25.6% below the postcode norm.