21, GRASMERE AVENUE, HARPENDEN, AL5 5PT - £1,525,000

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

21 GRASMERE AVENUE is a large extended detached house of 209m², built sometime between 1950 and 1966, which could now be worth an estimated £1,785,460. It was last sold for £1,525,000 in May 2021, which was around 43% above the average May 2021 detached price in the St Albans local authority area. The most recent EPC inspection was January 2022, where the current energy rating was D, and the potential energy rating was C.

21 GRASMERE AVENUE Sold Prices

Land registry data shows two sales for 21 GRASMERE AVENUE since 1^st January 1995. The below table shows the price paid for the two sales, along with the average detached price in the St Albans local authority area for the corresponding sale date. Both of the two 21 GRASMERE AVENUE sales were for above 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
2021 28 MAY	£1,525,000	£1,062,980	43% above HPI
2000 24 JUL	£500,000	£367,122	36% above HPI

21 GRASMERE AVENUE Price Paid vs. HPI Average

The below graph shows the average detached house price in the St Albans local authority area over time, sourced from the HPI. The two 21 GRASMERE AVENUE sales from July 2000 and May 2021 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 2000 sale was for 36% above the HPI. So the extrapolation line tracks at 36% above the HPI over time, until the May 2021 sale, where it rises to 43% above the HPI. The line then continues to track at 43% above the HPI.

What might 21 GRASMERE AVENUE be worth now?

21 GRASMERE AVENUE might now be worth an estimated £1,785,460.

This is based on house price inflation of 17.1%, between May 2021 and December 2024, for detached houses, in the St Albans local authority area, as calculated by the Office for National Statistics and published in their UK House Price Index (HPI).

The 17.1% inflationary increase is applied to the most recent sale price for 21 GRASMERE AVENUE of £1,525,000 on 28th May 2021. For the value to have increased from £1,525,000 to £1,785,460 over the two years and five months to December 2024, the following assumptions must hold true:

• The value of 21 GRASMERE AVENUE has moved in line with the HPI for detached houses in the St Albans local authority area.
• The May 2021 sale price of £1,525,000 represented a fair market value for the property.
• The size, condition, and specification of 21 GRASMERE AVENUE has not materially changed since May 2021.

How Large is 21 GRASMERE AVENUE?

21 GRASMERE AVENUE is 209m², which includes four extensions, according to the EPC inspection conducted in January 2022. This puts it in the largest 40% of detached houses houses in Harpenden, based on EPC data. The below chart shows the distribution of detached houses houses by size in Harpenden, and where 21 GRASMERE AVENUE lies on this distribution: 69% of detached houses houses are smaller than 21 GRASMERE AVENUE, and 30% of houses are larger. Note that EPC data is not available for all properties in Harpenden.

21 GRASMERE AVENUE: Plot and Title Map

21 GRASMERE AVENUE sits on a plot of roughly 0.169 of an acre, or 684m². The below map shows the location of 21 GRASMERE AVENUE, 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 21 GRASMERE AVENUE). 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 21 GRASMERE AVENUE?

21 GRASMERE AVENUE is located in HARPENDEN, in the AL5 postcode district. The below map shows the position of No. 21 on GRASMERE AVENUE.