21a, St Johns Road, Isleworth, TW7 6NB
About 21a
21a is a semi-detached house in Isleworth (TW7 6NB). It has a recorded floor area of 55 m² (around 592 sq ft) and construction records dating it to before 1900. The latest certificate (March 2016) shows an E (score 48), well below the UK norm with real room to improve. The latest certificate is from March 2016, so improvements made since then won't be reflected. At 55 m² this is the 18th smallest of 22 units on EPC record in the building, where floor areas span 20–114 m². The building's EPC ratings span F to C across 22 units on file.
Untraded for 19 years, with the last transfer in August 2007. That sale landed at the peak of the pre-credit-crunch market, which is a useful reference point when interpreting the price. At 55 m² it's 19.6% larger than the typical home in the postcode (46 m² median across 21 EPCs). On energy efficiency it sits in the bottom 10% of properties in this postcode — significant headroom for improvement. Today's modelled estimate of £476,000 is 19.6% above the 2007 sale price. On a £-per-square-foot basis, the last sale (£672/sq ft) was about 77.2% above the typical sold price in the postcode.
Know exactly what you're buying at 21a
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
Energy performance
21a sits at the bottom of the postcode for energy efficiency — meaningful headroom to improve.
EPC Expired
This certificate is over 10 years old and is no longer valid.Expired 21 Mar 2026
EPC Rating
Planning history
21a has no planning applications on record.
Notable planning nearby
6applications of note in the surrounding area
We flagged 2 things worth checking at 21a
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.
- Signs of HMO activity in the area
- Larger development activity nearby
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Sales history & valuation
The latest sale landed at the peak of the pre-credit-crunch market — a high-water reference point.
£476,000
Modelled from EPC, postcode comparables.
£398,000
Recorded with HM Land Registry.
Sales timeline
8 August 2007Most recent
£398,000
Median price across the last 5 sales in TW7 6NB: £221,000 (2022–2008).
Nearby sales in TW7 6NB
25b, St Johns Road, Isleworth, TW7 6NB
Sold Jun 2022
£200,00025a, St Johns Road, Isleworth, TW7 6NB
Sold Jun 2022
£221,000Flat A, 23 St Johns Road, Isleworth, TW7 6NB
Sold Jun 2022
£520,0001 Floriston Villas, St Johns Road, Isleworth, TW7 6NB
Sold Jan 2021
£1,00015a, St Johns Road, Isleworth, TW7 6NB
Sold Apr 2008
£240,000
Everything we know about 21a, in one report
What it's really worth, what could be wrong, and the planning, sales and area data in full.
What we flagged
- Signs of HMO activity in the area
- Larger development activity nearby
Versus other St Johns Road homes
21a is notably below the street on epc rating.
Price per m²
£7,236
Street avg £6,006
Floor Area
55 m²
Street avg 46 m²
Habitable Rooms
3 rooms
Street avg 2 rooms
CO₂ Emissions
4.1 t/year
Street avg 2.1 t/year
Similar properties nearby
The neighbourhood at a glance
Rail-style transport is unusually close for this postcode.
Crime
3/mo
Steady year-on-year across the wider district.
Nearest stop
0.1 km
Isleworth Station / Rennels Way — bus stop.
Closest school
0.3 km
West Thames College. 47 schools nearby.
Go deeper on the local area
The full report breaks down crime, transport links, schools and air quality in depth.
Road noise across the postcode
Daytime· 07:00 – 23:00
53.6dB
Night-time· 23:00 – 07:00
43.3dB