1 Robert Street, Northampton, NN1 3BL

1 Robert Street is a three-bedroom mid-terrace house in Northampton (NN1 3BL). It has a recorded floor area of 129 m² (around 1389 sq ft), construction records dating it to 1900-1929 and council tax band D. The latest certificate (January 2017) shows a D (score 61), on the cusp of jumping into the C band. When first surveyed in October 2010 the rating was E, the property has climbed 1 band since. Between certificates, wall efficiency went from Very Poor to Poor, roof efficiency went from Very Poor to Good and lighting went from Poor to Average; while hot-water efficiency dropped from Very Good to Good and main heating dropped from Very Good to Good. The recommended improvements would lift it to B (score 84), a 2-band jump.

Held since September 2007 — that's 19 years off the open market, well above the local norm. Across the public record there are 4 sales, relatively high churn for a single property. That sale landed at the peak of the pre-credit-crunch market, which is a useful reference point when interpreting the price. At 129 m² the property is well over the postcode median (77 m² across 11 EPCs), placing it in the larger end of the local stock. Across 1999–2007, sale prices on this property compounded at 5.7% per year. Today's modelled estimate of £287,000 sits 85.2% above the 2007 sale of £155,000.