21a, Gowlett Road, Southwark, London, SE15 4HX

21a is a one-bedroom mid-terrace house in Southwark, London, London (SE15 4HX). It has a recorded floor area of 45 m² (around 484 sq ft), construction records dating it to before 1900 and council tax band C. Tenure is freehold. The latest certificate (October 2022) shows a D (score 63), on the cusp of jumping into the C band. Earlier certificates rated it C (May 2010); the latest reading is one band lower. Between certificates, window efficiency went from Poor to Average and lighting went from Average to Very Good; while wall efficiency dropped from Good to Very Poor. The recommended improvements would push it to C (score 76). At 45 m² this is the 2nd smallest of 30 units on EPC record in the building, where floor areas span 30–186 m². The building's EPC ratings span G to C across 30 units on file. Our model identifies extension potential, subject to local planning policy.

At 45 m² it sits well below the postcode median (65 m² across 31 EPCs), making it one of the more compact homes locally. 1 bedrooms is on the smaller side for this postcode, where 3 is the typical count. One planning record on file: an extension approved in 2025. Past consents include an extension, meaningful when judging how the property has evolved. Across 2002–2024, sale prices on this property compounded at 6.4% per year. On a £-per-square-foot basis, the last sale (£1,063/sq ft) was about 168.8% above the typical sold price in the postcode. Sold September 2024 for £515,000.