18 Blackwell House, The Embankment, Nash Mills Wharf, Hemel Hempstead, HP3 9FX

18 Blackwell House is a two-bedroom property in Nash Mills Wharf, Hemel Hempstead, Hemel Hempstead (HP3 9FX). It has a recorded floor area of 48 m² (around 517 sq ft), construction records dating it to 2012-2021 and council tax band D. The latest certificate (December 2025) returns a B (score 82), comfortably above the UK average. When first surveyed in October 2015 the rating was C, the property has climbed 1 band since. Between certificates, hot-water efficiency went from Very Poor to Average and main heating went from Very Poor to Poor; while wall efficiency dropped from Very Good to Good and window efficiency dropped from Very Good to Average. Main heating runs on electricity. This certificate was lodged in the last six months, so the rating reflects current condition. At 48 m² this is the 4th smallest of 36 units on EPC record in the building, where floor areas span 46–83 m². The building's EPC ratings span D to B, with this unit at the top. Other recorded features include a balcony.

Today's modelled estimate of £274,000 is 11.6% below the 2015 sale of £309,950, running counter to the wider postcode trend, which makes the EPC and condition history especially worth a look. On a £-per-square-foot basis, the last sale (£600/sq ft) was about 39.4% above the typical sold price in the postcode. At 48 m² it's 29.4% smaller than the typical home in the postcode (68 m² median across 35 EPCs). On energy efficiency it sits in the top 10% of properties in this postcode. 10 years since the last transfer (December 2015).