21 St Stephens Mansions, Mount Stuart Square, Cardiff, CF10 5LQ

21 St Stephens Mansions is a two-bedroom mid-terrace house in Cardiff (CF10 5LQ). It has a recorded floor area of 94 m² (around 1012 sq ft), construction records dating it to 2003-2006 and council tax band F. The latest certificate (October 2020) shows a C (score 75), near the top of the C band. The rating has held steady at C across 3 certificates since June 2009. Between certificates, lighting went from Poor to Very Good; while window efficiency dropped from Good to Average and hot-water efficiency dropped from Average to Poor. The recommended improvements would push it to B (score 82). Main heating runs on electricity. At 94 m² this is the 60th smallest of 64 units on EPC record in the building, where floor areas span 48–99 m². The building's EPC ratings span E to B across 64 units on file.

At 94 m² the property is well over the postcode median (71 m² across 63 EPCs), placing it in the larger end of the local stock. Across 2004–2019, sale prices on this property compounded at -1.3% per year. Today's modelled estimate of £204,000 is 20% above the 2019 sale price. On a £-per-square-foot basis, the last sale (£168/sq ft) was about 19.6% below the postcode norm. Most recent transfer: October 2019 at £170,000.