27 The Swallows, Welwyn Garden City, AL7 1BX

27 The Swallows is a three-bedroom semi-detached house in Welwyn Garden City (AL7 1BX). It has a recorded floor area of 57 m² (around 614 sq ft), construction records dating it to 1976-1982 and council tax band D. The latest certificate (March 2020) shows a D (score 68), on the cusp of jumping into the C band. Earlier certificates rated it C (May 2009); the latest reading is one band lower. Between certificates, roof efficiency went from Average to Good, window efficiency went from Average to Good and lighting went from Poor to Very Good; while wall efficiency dropped from Good to Average and hot-water efficiency dropped from Very Good to Good. The recommended improvements would lift it to B (score 88), a 2-band jump.

It hasn't traded since November 1998, a hold of 27 years that's notably long for the area. Only one transfer is on record with HM Land Registry, suggesting it has stayed in the same hands for a long time. Today's modelled estimate of £406,000 sits 314.3% above the 1998 sale of £98,000. On a £-per-square-foot basis, the last sale (£160/sq ft) was about 33.5% below the postcode norm.