28a is a four-bedroom detached house in Croydon, Royston, Royston (SG8 0DN). It has a recorded floor area of 146 m² (around 1572 sq ft), construction records dating it to 1983-1990 and council tax band E. The latest certificate (August 2025) shows a D (score 61), on the cusp of jumping into the C band. When first surveyed in January 2009 the rating was E, the property has climbed 1 band since. Between certificates, hot-water efficiency went from Poor to Average; while window efficiency dropped from Average to Poor. Main heating runs on oil. Other recorded features include notable views, a conservatory and a basement.
Held since March 2009 — that's 17 years off the open market, well above the local norm. Across the public record there are 4 sales, relatively high churn for a single property. That sale fell during the post-crash dip, which often skews comparisons against later neighbouring sales. Sale prices here have outpaced England HPI: 1.9% per year against 0% for the wider region. Today's modelled estimate of £528,000 sits 164% above the 2009 sale of £200,000. On a £-per-square-foot basis, the last sale (£127/sq ft) was about 33% below the postcode norm. 2 planning records sit against the property, 2 approved, 0 refused.
28a's carbon output runs well above what efficient homes in the postcode produce.
Non material amendment of planning permission S/2429/15/FL for adding 2 velux windows
28a's estimated value is more than triple its earliest registered sale price (2002).
£528,000
Modelled from EPC, postcode comparables and a sale-price growth of 1.9% per year over 7 years.
£200,000
Growth on file: 1.9% per year over 7 years.
Everything we know about this property, compiled into one in-depth, downloadable report.
Detailed analysis
A written breakdown of everything that matters
28a is notably below the street on price per m².
Price per m²
£1,370
Street avg £3,451
Floor Area
146 m²
Street avg 166 m²
Habitable Rooms
6 rooms
Street avg 7 rooms
Daytime road noise here sits well below conversation level — a quiet pocket of the postcode.
Crime
3/mo
Steady year-on-year across the wider district.

Daytime· 07:00 – 23:00
41.4dB

Launch offer
Secure checkout · One-off payment
30-day money-back guarantee

Changes detected from historical EPC data
Replaced storage heaters with gas boiler
Fuel source changed
Hot water system upgraded
Roof insulation improved
Low energy lighting percentage decreased
Loft insulation upgraded to recommended levels
More low energy lighting installed
Roof Alterations to include Change of Ridge Height Two New Dormers and New Rooflights
Full planning data for 28a, High Street, Croydon, Royston, SG8 0DN
Every application and decision on this property and nearby, in full, in the report.
10 March 2009Most recent
£200,000
-7.0%15 January 2009
£215,000
-6.5%over 4 years11 June 2004
£230,000
+31.4%over 2 years22 March 2002
£175,000
Median price across the last 5 sales in SG8 0DN: £405,000 (2019–2014).
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
Ad-free · Secure Stripe checkout · One-off payment
30-day money-back guarantee

CO₂ Emissions
6.3 t/year
Street avg 6.0 t/year
SG8 0RB
Night-time· 23:00 – 07:00
35.6dB