21 Arethusa House, Gunwharf Quays, Portsmouth, PO1 3TQ

21 Arethusa House is a two-bedroom mid-terrace house in Portsmouth (PO1 3TQ). It has a recorded floor area of 95 m² (around 1023 sq ft), construction records dating it to 1996-2002 and council tax band E. The latest certificate (June 2020) shows a C (score 74). The rating has held steady at C across 2 certificates since May 2010. Between certificates, lighting went from Average to Very Good; while hot-water efficiency dropped from Good to Very Poor and main heating dropped from Good to Very Poor. Main heating runs on electricity. At 95 m² this is the 26th smallest of 52 units on EPC record in the building, where floor areas span 59–171 m². The building's EPC ratings span E to B across 52 units on file. Other recorded features include a balcony.

Held since April 2002 — that's 24 years off the open market, well above the local norm. Today's modelled estimate of £397,000 sits 103.6% above the 2002 sale of £195,000. On a £-per-square-foot basis, the last sale (£191/sq ft) was about 42.7% below the postcode norm.