3 Harmer Dell, Welwyn, AL6 0BE

3 Harmer Dell is a five-bedroom detached house in Welwyn (AL6 0BE). It has a recorded floor area of 262 m² (around 2823 sq ft), construction records dating it to 1976-1982 and council tax band G. The latest certificate (September 2009) shows a D (score 59), a step below the typical UK home. When first surveyed in November 2008 the rating was E, the property has climbed 1 band since. Between certificates, wall efficiency went from Poor to Average, hot-water efficiency went from Good to Very Good and lighting went from Poor to Average; while roof efficiency dropped from Average to Poor. The latest certificate is from September 2009, so improvements made since then won't be reflected.

Across 1999–2011, sale prices on this property compounded at 6.5% per year. Today's modelled estimate of £1,515,000 sits 53.8% above the 2011 sale of £985,000. On a £-per-square-foot basis, the last sale (£349/sq ft) was about 21.6% below the postcode norm. On the market in July 2011 and unlisted since — roughly 15 years. Across the public record there are 4 sales, relatively high churn for a single property. 4 planning records sit against the property, 3 approved, 1 refused. Past consents include an extension and tree works, meaningful when judging how the property has evolved.