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

3 St James Mansions is a two-bedroom semi-detached house in Cardiff (CF10 5LG). It has a recorded floor area of 40 m² (around 431 sq ft), construction records dating it to 1983-1990 and council tax band D. At 40 m² this is the smallest unit on EPC record across 3 St James Mansions (40–65 m²). The building's EPC ratings span D to C, with this unit at the bottom. On EPC score it ranks last in the building (60 versus a best of 74). The latest certificate (August 2012) shows a D (score 60), on the cusp of jumping into the C band. Earlier certificates rated it C (March 2010); the latest reading is one band lower. Between certificates, window efficiency dropped from Good to Average and hot-water efficiency dropped from Average to Very Poor. Main heating runs on electricity. The latest certificate is from August 2012, so improvements made since then won't be reflected.

Untraded for 24 years, with the last transfer in June 2002. Today's modelled estimate of £138,000 sits 84% above the 2002 sale of £75,000. At 40 m² it sits well below the postcode median (59 m² across 23 EPCs), making it one of the more compact homes locally.