23 Cowen Avenue, Harrow, HA2 0LU

23 Cowen Avenue is a two-bedroom end-of-terrace house in Harrow (HA2 0LU). It has a recorded floor area of 60 m² (around 646 sq ft), construction records dating it to 1967-1975 and council tax band C. The latest certificate (May 2015) shows an E (score 49), well below the UK norm with real room to improve. When first surveyed in June 2010 the rating was F, the property has climbed 1 band since. Between certificates, roof efficiency went from Very Poor to Average and main heating went from Poor to Average; while wall efficiency dropped from Poor to Very Poor. The recommended improvements would lift it to C (score 70), a 2-band jump. Main heating runs on electricity. The latest certificate is from May 2015, so improvements made since then won't be reflected.

Held since August 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. On energy efficiency it sits in the bottom 10% of properties in this postcode — significant headroom for improvement. Across 2001–2007, sale prices on this property compounded at 12.1% per year. Today's modelled estimate of £328,000 sits 55.5% above the 2007 sale of £211,000. On a £-per-square-foot basis, the last sale (£327/sq ft) was about 42.6% above the typical sold price in the postcode.