15 St James Mansions, Mount Stuart Square, Cardiff, CF10 5LG

15 St James Mansions is a one-bedroom mid-terrace house in Cardiff (CF10 5LG). It has a recorded floor area of 39 m² (around 420 sq ft), construction records dating it to 1991-1995 and council tax band D. At 39 m² this is the smallest unit on EPC record across the building (39–92 m²). The building's EPC ratings span D to B across 24 units on file. The latest certificate (April 2013) shows a C (score 73). Main heating runs on electricity. The latest certificate is from April 2013, so improvements made since then won't be reflected.

It hasn't traded since June 2008, a hold of 18 years that's notably long for the area. That sale landed at the peak of the pre-credit-crunch market, which is a useful reference point when interpreting the price. At 39 m² it sits well below the postcode median (59 m² across 23 EPCs), making it one of the more compact homes locally. Across 2002–2008, sale prices on this property compounded at 2.9% per year. Today's modelled estimate of £120,000 is 18.8% above the 2008 sale price. On a £-per-square-foot basis, the last sale (£241/sq ft) was about 29.2% above the typical sold price in the postcode.