21 Harmer Green Lane, Welwyn, AL6 0AS
About 21 Harmer Green Lane
21 Harmer Green Lane is a four-bedroom semi-detached house in Welwyn (AL6 0AS). It has a recorded floor area of 150 m² (around 1615 sq ft), construction records dating it to before 1900 and council tax band E. The latest certificate (June 2010) shows a D (score 56), a step below the typical UK home. The recommended improvements would push it to C (score 71). The latest certificate is from June 2010, so improvements made since then won't be reflected. Other recorded features include a conservatory and a self-contained annexe. Records show the property has been extended at some point in its history.
At 150 m² it sits well below the postcode median (233 m² across 7 EPCs), making it one of the more compact homes locally. Last sale on file: £775,000 in March 2019. Across the public record there are 4 sales, relatively high churn for a single property. 2 planning records sit against the property, 2 approved, 0 refused. Past consents include an extension, partial demolition and a conservatory, meaningful when judging how the property has evolved. Across 1998–2019, sale prices on this property compounded at 6.7% per year. Today's modelled estimate of £869,000 is 12.1% above the 2019 sale price. On a £-per-square-foot basis, the last sale (£480/sq ft) was about 51.4% above the typical sold price in the postcode.
Know exactly what you're buying at 21 Harmer Green Lane
Before you offer, see what the listing won't tell you, the true value, the red flags and the full history.
Already flagged here
Valuation
against the asking price
Risks
planning & flood
Sold prices
similar homes nearby
Trends
the local market
What this property has
Inside
- Bedrooms4
- Bathrooms3
- Dining roomYes
- EnsuiteYes
- ConservatoryYes
Outside
- Private gardenSouth-facing
- DrivewayYes
Building
- Previously extendedYes
Energy performance
21 Harmer Green Lane's carbon output runs well above what efficient homes in the postcode produce.
EPC Expired
This certificate is over 10 years old and is no longer valid.Expired 02 Jun 2020
EPC Rating
Planning history
Planning history includes recorded demolition works, indicating a major rebuild phase at this address.
- Jul 2019DemolitionFullIn report
Extension: Part single, part two storey
Erection of single storey front extension and part two storey, part single storey rear extension following demolition of existing rear conservatory.
Extension- Reference
- 6/2019/0908/HOUSE
- Jul 2001ConservatoryFullIn report
ERECTION OF CONSERVATORY
Extension- Reference
- N6/2001/0601/FP
We flagged 1 thing worth checking at 21 Harmer Green Lane
Independent checks surfaced things a buyer would want to understand before offering. The report explains each one in full, with the underlying data and what to ask.
- Larger development activity nearby
30-day money-back guarantee
Sales history & valuation
21 Harmer Green Lane has more than tripled in price since its earliest registered sale in 1998.
£869,000
Modelled from EPC, postcode comparables and a sale-price growth of 6.7% per year over 21 years.
£775,000
Growth on file: 6.7% per year over 21 years.
Sales timeline
22 March 2019Most recent
£775,000
+75.3%over 7 years7 April 2011
£442,000
+5.2%over 4 years20 September 2006
£420,000
+104.9%over 8 years28 July 1998
£205,000
Median price across the last 5 sales in AL6 0AS: £840,000 (2025–2011).
Nearby sales in AL6 0AS
Everything we know about 21 Harmer Green Lane, in one report
What it's really worth, what could be wrong, and the planning, sales and area data in full.
What we flagged
- Larger development activity nearby
Versus other Harmer Green Lane homes
EPC Rating for 21 Harmer Green Lane lags the street by a wide margin.
Price per m²
£5,167
Street avg £3,869
Floor Area
150 m²
Street avg 232 m²
Habitable Rooms
6 rooms
Street avg 8 rooms
CO₂ Emissions
6.9 t/year
Street avg 5.8 t/year
Similar properties nearby
The neighbourhood at a glance
Rail-style transport is unusually close for this postcode.
Crime
2/mo
Steady year-on-year across the wider district.
Nearest stop
0.3 km
Mornington — bus stop.
Closest school
0.9 km
St John's CofE Primary School. 14 schools nearby.
Go deeper on the local area
The full report breaks down crime, transport links, schools and air quality in depth.