THORNBURY, BIRCHWOOD PARK AVENUE, SWANLEY, BR8 7AT - £397,500

Based on the January 2025 Price Paid Data (released on 3rd March 2025), the December 2024 House Price Index (released on 19th February 2025), and the January 2025 Energy Performance of Buildings Data (released on 27th February 2025). Sources

THORNBURY is a large detached house of 141m², built sometime between 2003 and 2006, which could now be worth an estimated £736,774. It was last sold for £397,500 in November 2009, which was around 22% below the average November 2009 detached price in the Sevenoaks local authority area. The most recent EPC inspection was October 2009, where the current energy rating was C, and the potential energy rating was C.

THORNBURY Sold Prices

Land registry data shows four sales for THORNBURY since 1^st January 1995. The below table shows the price paid for the four sales, along with the average detached price in the Sevenoaks local authority area for the corresponding sale date. All of the four THORNBURY sales were for below the average price. The average price is sourced from the Office for National Statistics' House Price Index (HPI).

Date	Price	HPI Price	Variation from HPI
2009 30 NOV	£397,500	£509,568	22% below HPI
2006 28 JUL	£390,000	£479,723	19% below HPI
2004 19 MAY	£335,000	£433,069	23% below HPI
2002 1 OCT	£330,000	£384,386	14% below HPI

THORNBURY Price Paid vs. HPI Average

The below graph shows the average detached house price in the Sevenoaks local authority area over time, sourced from the HPI. The four THORNBURY sales between October 2002 and November 2009 have been plotted on the graph. A line has been extrapolated to show what the value of the property might have been over time, following each sale, had it maintained the same margin above or below the HPI (as a percentage). For example, the July 2006 sale was for 19% below the HPI. So the extrapolation line tracks at 19% below the HPI over time, until the November 2009 sale, where it falls to 22% below the HPI. The line then continues to track at 22% below the HPI.

What might THORNBURY be worth now?

THORNBURY might now be worth an estimated £736,774.

This is based on house price inflation of 85.4%, between November 2009 and December 2024, for detached houses, in the Sevenoaks local authority area, as calculated by the Office for National Statistics and published in their UK House Price Index (HPI).

The 85.4% inflationary increase is applied to the most recent sale price for THORNBURY of £397,500 on 30th November 2009. For the value to have increased from £397,500 to £736,774 over the fourteen years and eleven months to December 2024, the following assumptions must hold true:

• The value of THORNBURY has moved in line with the HPI for detached houses in the Sevenoaks local authority area.
• The November 2009 sale price of £397,500 represented a fair market value for the property.
• The size, condition, and specification of THORNBURY has not materially changed since November 2009.

How Large is THORNBURY?

THORNBURY is 141m² according to the EPC inspection conducted in October 2009. This puts it in the largest 30% of detached houses houses in Swanley, based on EPC data. The below chart shows the distribution of detached houses houses by size in Swanley, and where THORNBURY lies on this distribution: 77% of detached houses houses are smaller than THORNBURY, and 23% of houses are larger. Note that EPC data is not available for all properties in Swanley.

THORNBURY: Plot and Title Map

THORNBURY sits on a plot of roughly 0.152 of an acre, or 616m². The below map shows the location of THORNBURY, an approximate outline of the building(s), and the indicative extent of the property. The plot extent is a Land Registry INSPIRE Index Polygon, and it is important to note that a title may include more than one polygon, whereas only one polygon is shown on the map (the polygon which intersects with the position of THORNBURY). The full extent of the land contained in any registered title can only be identified from the individual title plan. The maps on this page should not be relied upon to establish the extent of a title.

Where is THORNBURY?

THORNBURY is located on BIRCHWOOD PARK AVENUE in SWANLEY, in the BR8 postcode district. The below map shows the position of THORNBURY on BIRCHWOOD PARK AVENUE.