9 William Street, Ystradgynlais, Swansea, SA9 1AT
About 9 William Street
9 William Street is a mid-terrace house in Ystradgynlais, Swansea, Swansea (SA9 1AT). It has a recorded floor area of 64 m² (around 689 sq ft), construction records dating it to 1930-1949 and council tax band B. The latest certificate (November 2019) shows a D (score 65), on the cusp of jumping into the C band. The recommended improvements would lift it to B (score 83), a 2-band jump.
It hasn't traded since September 1999, 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 £140,000 sits 409.1% above the 1999 sale of £27,500. On a £-per-square-foot basis, the last sale (£40/sq ft) was about 56.5% below the postcode norm. At 64 m² it's 24.7% smaller than the typical home in the postcode (85 m² median across 13 EPCs).
Know exactly what you're buying at 9 William Street
Before you offer, see what the listing won't tell you, the true value, the red flags and the full history.
Already flagged here
Launch offer · save £5
Valuation
against the asking price
Risks
planning & flood
Sold prices
similar homes nearby
Trends
the local market
Energy performance
Recommended upgrades on file would lift this property by multiple EPC bands.
EPC Rating
Planning history
9 William Street has no planning applications on record.
Notable planning nearby
2applications of note in the surrounding area
We flagged 1 thing worth checking at 9 William Street
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
9 William Street's modelled value sits at over four times its earliest registered sale price (1999).
£140,000
Modelled from EPC, postcode comparables.
£27,500
Recorded with HM Land Registry.
Sales timeline
1 September 1999Most recent
£27,500
Median price across the last 5 sales in SA9 1AT: £127,000 (2025–2019).
Nearby sales in SA9 1AT
2 William Street, Ystradgynlais, Swansea, SA9 1AT
Sold Jul 2025
£209,95020 William Street, Ystradgynlais, Swansea, SA9 1AT
Sold Dec 2023
£125,00015 William Street, Ystradgynlais, Swansea, SA9 1AT
Sold Mar 2021
£127,000Ty Gardd, William Street, Ystradgynlais, Swansea, SA9 1AT
Sold Nov 2019
£235,0003 William Street, Ystradgynlais, Swansea, SA9 1AT
Sold Apr 2019
£85,000
Everything we know about 9 William Street, 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 William Street homes
Price per m² for 9 William Street lags the street by a wide margin.
Price per m²
£430
Street avg £1,154
Floor Area
64 m²
Street avg 89 m²
Habitable Rooms
3 rooms
Street avg 5 rooms
CO₂ Emissions
3.1 t/year
Street avg 5.0 t/year
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The neighbourhood at a glance
Crime
6/mo
Steady year-on-year across the wider district.
Nearest stop
0.1 km
Glanrhyd Hospital — bus stop.
Go deeper on the local area
The full report breaks down crime, transport links, schools and air quality in depth.