11a is a semi-detached house in Byram, Knottingley, Knottingley (WF11 9DY). It has a recorded floor area of 37 m² (around 398 sq ft), construction records dating it to 1950-1966 and council tax band A. The latest certificate (October 2019) shows a C (score 69), just inside the C band. When first surveyed in July 2009 the rating was F, the property has climbed 3 bands since. Between certificates, hot-water efficiency went from Average to Very Good, lighting went from Very Poor to Very Good and main heating went from Poor to Good; while wall efficiency dropped from Good to Average and window efficiency dropped from Good to Average. At 37 m² this is the 3rd smallest of 37 units on EPC record in the building, where floor areas span 36–109 m². The building's EPC ratings span G to B across 37 units on file.
At 37 m² it sits well below the postcode median (80 m² across 36 EPCs), making it one of the more compact homes locally.
No planning applications are recorded against 11a, West Acres, Byram, Knottingley, WF11 9DY. The full report also covers planning activity across the surrounding area.
Full planning data for 11a, West Acres, Byram, Knottingley, WF11 9DY
Every application and decision on this property and nearby, in full, in the report.
11a has no Land Registry sales on file, suggesting it has stayed in the same hands since registration began.
£119,000
Modelled from EPC, postcode comparables.
That can mean the property has never traded since the registry began publishing in 1995, was a new build that hasn't been registered yet, or is held in the same hands long-term.
Everything we know about this property, compiled into one in-depth, downloadable report.
Detailed analysis
A written breakdown of everything that matters
CO₂ Emissions for 11a runs comfortably ahead of the street norm.
EPC Rating
69 (C)
Street avg 66 (D)
Floor Area
37 m²
Street avg 53 m²
CO₂ Emissions
1.7 t/year
Street avg 3.3 t/year
Crime
5/mo
Steady year-on-year across the wider district.
Nearest stop
0.0 km
West Acres — bus stop.

Daytime· 07:00 – 23:00
50.4dB

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Changes detected from historical EPC data
Replaced storage heaters with gas boiler
Connected to mains gas supply
Heating controls upgraded for better temperature management
Hot water system upgraded
More low energy lighting installed
Median price across the last 5 sales in WF11 9DY: £189,000 (2025–2024).
Detailed EPC data
Full energy ratings, history and recommendations
Full planning history
Every application and decision on record
Comparable sales data
Plus transport, crime, schools and air quality
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Habitable Rooms
2 rooms
Street avg 2 rooms
Closest school
0.5 km
Brotherton and Byram Community Primary Academy. 9 schools nearby.
Night-time· 23:00 – 07:00
41.9dB