11 Excalibur Close, Northampton, NN5 4BJ

11 Excalibur Close is a five-bedroom detached house in Northampton (NN5 4BJ). It has a recorded floor area of 178 m² (around 1916 sq ft), construction records dating it to 1991-1995 and council tax band F. The latest certificate (October 2015) shows a D (score 59), a step below the typical UK home. The rating has held steady at D across 3 certificates since September 2009. Between certificates, hot-water efficiency went from Very Poor to Good and main heating went from Average to Good; while wall efficiency dropped from Good to Poor and lighting dropped from Very Good to Good. The recommended improvements would lift it to B (score 83), a 2-band jump. The latest certificate is from October 2015, so improvements made since then won't be reflected. Other recorded features include a conservatory.

Held since April 2010 — that's 16 years off the open market, well above the local norm. Today's modelled estimate of £562,000 sits 75.6% above the 2010 sale of £320,000. On a £-per-square-foot basis, the last sale (£167/sq ft) was about 32.3% above the typical sold price in the postcode.