23a, Carmarthen Street, Cardiff, CF5 1QG

23a is a two-bedroom end-of-terrace house in Cardiff (CF5 1QG). It has a recorded floor area of 50 m² (around 538 sq ft) and construction records dating it to 1900-1929. At 50 m² this is the 3rd smallest of 16 units on EPC record in the building, where floor areas span 38–132 m². The building's EPC ratings span E to C, with this unit at the bottom. The latest certificate (April 2017) shows an E (score 51), well below the UK norm with real room to improve. The recommended improvements would push it to D (score 67).

It hasn't traded since March 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 50 m² it sits well below the postcode median (75 m² across 15 EPCs), making it one of the more compact homes locally. It lags the bulk of the postcode on energy efficiency (less efficient than 80% of similar EPCs). Today's modelled estimate of £160,000 is 34.5% above the 2008 sale price. On a £-per-square-foot basis, the last sale (£221/sq ft) was about 26.4% above the typical sold price in the postcode.