12 Warrenhyrst, 15 Warren Road, Guildford, GU1 2HD

12 Warrenhyrst is a one-bedroom semi-detached house in Guildford (GU1 2HD). It has a recorded floor area of 46 m² (around 495 sq ft) and construction records dating it to 1967-1975. At 46 m² this is the 10th smallest of 15 units on EPC record in the building, where floor areas span 38–60 m². The building's EPC ratings span E to C, with this unit at the bottom. On EPC score it ranks last in the building (46 versus a best of 79). The latest certificate (August 2020) shows an E (score 46), well below the UK norm with real room to improve. The rating has held steady at E across 6 certificates since August 2010. Between certificates, hot-water efficiency went from Very Poor to Average, lighting went from Good to Very Good and main heating went from Poor to Average; while wall efficiency dropped from Average to Poor and roof efficiency dropped from Poor to Very Poor. The recommended improvements would lift it to C (score 75), a 2-band jump. Main heating runs on electricity.

Untraded for 26 years, with the last transfer in January 2001. Across 1998–2001, sale prices on this property compounded at -29.8% per year. Today's modelled estimate of £224,000 sits 118.5% above the 2001 sale of £102,500. On a £-per-square-foot basis, the last sale (£207/sq ft) was about 37.6% below the postcode norm. It lags the bulk of the postcode on energy efficiency (less efficient than 88% of similar EPCs).