House prices in SL9 (Chalfont St Peter)
This article shows price per square metre data and various charts to help you understand the housing market in SL9 - stats were last calculated on 03 December 2024.
Defining 'SL9'
This analysis is limited to properties whose postcode starts with "SL9", this is also called the postcode district. There are no official postcode district names so I've just labelled it SL9, Chalfont St Peter. It is shown in red on the map below.
Want to change geography?
You can click on the map above to change to a neighbouring district, or you can use the search form below.
Price per square metre
Knowing the average house price in SL9 is not much use. However, knowing average price per square metre can be quite useful. Price per sqm allows some comparison between properties of different size. We define price per square metre as the sold price divided by the internal area of a property:
£ per sqm = price ÷ internal area
For example in October 2024, 4, Selman Way, Chalfont St Peter, SL9 0FE sold for £820,000. Given the internal area of 101 square metres recorded on the EPC, the price per sqm is £820,000 ÷ 101 sqm = £8,118.
England & Wales have been officially metric since 1965. However house price per square foot is prefered by some estate agents and those of sufficiently advanced age ;-). It is a huge pain to code the automatic conversion for square meters to square feet for all the graphs and charts on SL9 and elsewhere. All the conditionals turn my tidy code for into spaghetti. I will get around to it at some point, but for now you can just divide everything by 10 in your head, move a decimal place and you'll be close enough. If you want to be more precise 1 sqm = 10.76391 sqft.
Distribution of £ per sqm for houses vs flats in SL9
The chart above is called a histogram, it helps you see the distribution of house price per sqm in SL9 To make this chart we put all the sales data into a series of £ per sqm 'buckets' (e.g. £6,250 to £6,500, £6,500 to £6,750, £6,750 to £7,000 etc...) we then count the number of sales with within in each bucket and plot the results. The histogram is based on 439 sales that took place in SL9, in the last 24 months.
Generate a custom histogram like the one above but based on your own criteria.
You can see the spread of prices above. This is because although internal area is a key factor in determining valuation, it is not the only factor. Many factors other than size affect desirability; these factors could be condition, aspect, garden size, negotiating power of the vendor etc.
The spread of prices will give you a feel of the typical range to expect in SL9, Chalfont St Peter. Notably, only 25% of properties that sold recently were valued at more than £7,140 sqm. For anything to be valued more than this means it has to be more desireable than the clear majority of SL9 homes.
Box plot of £ per sqm for SL9
Tip: click on the chart to see the values.
The chart above is called a boxplot (or a box-and-whisker plot). Box plots, like histograms, are used to graphically represent the distribution of data, showing the central tendency, spread of the distribution. In the context of £ per square metre property price distributions, box plots represent the variation in property prices within a geographic area e.g. Chalfont St Peter. The chart above shows a boxplot for 'SL9' as well as the 'SL' postcode area.
Property price map for Chalfont St Peter
Have a look at the interactive price map I created for myself. Use it to explore 'SL9' house prices all the way down to individual property plots.
House price map for Chalfont St PeterWill SL9 house prices drop in 2025?
I cannot tell what house prices will do in the future and don't believe anyone who says they can. However we can plot price trends, I have done this in the chart below for SL9 (Chalfont St Peter) compared with the wider postcode area 'SL'. You can extrapolate from this based on your own views on future interest rates, inflation and other factors.
House price index for SL9
Tip: click on the legend items to show/hide different lines
Download house price index as CSV (premium users only).
The chart above shows changes in 'SL9' property prices over the last 20 years. The index is calculated from the average price paid per sqm for property in SL9 and is set to 100 in 2004. The chart compares trends for SL9, Chalfont St Peter against those of the broader postcode area 'SL'. What is more interesting is to look at the difference between flats and houses, even those in the same area follow a very different trend, to get a robust enough sample size to see this we need to zoom out and look at house price trends for the entire Buckinghamshire local authority.
The dashed lines show nominal house price changes, the solid lines show the same data adjusted for inflation. Economists call this the 'real' price change. You have to take inflation into account when comparing prices over time. It's calculated using the formula:
Real Rate of Return = (1 + Nominal Rate) ÷ (1 + Inflation Rate) – 1In this formula, the nominal rate is the rate of change before any adjustments, and the inflation rate is taken from the Consumer Price Index. The real rate of return is a more accurate measure of change in value, because £1 today does not have the same buying power as £1 in the past. For example, if a savings account pays an interest rate of 3% per year and the inflation rate is 5% per year, the real rate of return is -2%. This means that the investment's value is shrinking by 2% each year.
Historic returns for SL9
| SL area | SL9 district | |||
|---|---|---|---|---|
| Nominal | Real | Nominal | Real | |
| 20 yr per annum | 3.6% | 0.9% | 3.5% | 0.9% |
| 20 yr total | 102.6% | 20.0% | 100.3% | 18.6% |
| 10 yr per annum | 3.2% | 0.4% | 2.2% | -0.6% |
| 10 yr total | 37.5% | 4.4% | 24.6% | -5.4% |
| 5 yr per annum | 2.1% | -1.9% | 1.2% | -2.8% |
| 5 yr total | 11.2% | -9.0% | 6.3% | -13.0% |
| 1 yr per annum | 0.3% | -3.7% | -5.6% | -9.4% |
| 1 yr total | 0.3% | -3.7% | -5.6% | -9.4% |
This table complements the house price index chart above, presenting the data in a more detailed format. It breaks down the information into 20-year, 10-year, 5-year, and 1-year periods, further categorized by property type. For each period, we display both a per annum rate of change and a total rate of change.
The total rate of change represents the overall change over the entire period. The formula for total return is:
Total return = (Index at end of period ÷ Index at start of period) - 1
The per annum rate of change is the annualized rate of change over the period. This is equivalent to the annual bank savings rate you would need to achieve the same total return over the given period. This annualized return is also known as the Compound Annual Growth Rate (CAGR). The formula for CAGR is:
CAGR = (1 + Total return) ^ (1 ÷ Number of years) - 1
Some specific examples:
- Over the past 20 years, SL9 district have seen a 0.9% annual change when adjusted for inflation. This translates to a total change of 18.6% in real terms.
- Over the past 5 years, SL9 district have seen a -2.8% annual change when adjusted for inflation. This translates to a total change of -13.0% in real terms.
Most recent SL9 sales
For the most recent sales activity, rather than a summarized average, it is better to see the underlying data. This is shown in the chart below, where blue dots represent individual sales, click on them to see details. If there is an obvious trend you should be able to spot it here amid the noise from outliers.
Tip: hover over dots to see details
Street level data
| Street | Avg size | Avg £sqm | Recent sales |
|---|---|---|---|
| Grange Road, , SL9 9F | 71 sqm | £4,975 | 24 |
| Hill Rise, , SL9 9B | 170 sqm | £6,994 | 14 |
| Austenwood Close, , SL9 9D | 78 sqm | £6,031 | 13 |
| South Park Crescent, , SL9 8H | 215 sqm | £6,580 | 13 |
| Bull Lane, , SL9 8R | 153 sqm | £6,358 | 13 |
| High Beeches, , SL9 7H | 188 sqm | £7,855 | 13 |
| Orchard Grove, , SL9 9E | 116 sqm | £5,894 | 13 |
| Fulmer Drive, , SL9 7H | 334 sqm | £5,286 | 12 |
Search for your street here.
Nearby geographies
The table below shows how 'SL9' compares to the other postcode districts nearby 'SL9'.
| District | Lower quartile | Median | Upper quartile | Sales in last 2yr |
|---|---|---|---|---|
| WD3 Croxley Green | £5,440 sqm | £6,310 sqm | £7,110 sqm | 806 |
| UB9 Harefield | £4,810 sqm | £5,480 sqm | £6,180 sqm | 350 |
| UB8 Uxbridge | £4,830 sqm | £5,490 sqm | £6,180 sqm | 679 |
| SL9 Chalfont St Peter | £5,400 sqm | £6,180 sqm | £7,140 sqm | 439 |
| SL8 Bourne End | £5,480 sqm | £6,120 sqm | £6,850 sqm | 129 |
| SL7 Marlow | £5,300 sqm | £6,380 sqm | £7,340 sqm | 458 |
| SL6 Maidenhead | £4,620 sqm | £5,280 sqm | £5,990 sqm | 1,905 |
| SL5 Ascot | £4,940 sqm | £5,800 sqm | £6,630 sqm | 659 |
| SL4 Windsor | £4,870 sqm | £5,580 sqm | £6,530 sqm | 940 |
| SL3 Slough | £4,580 sqm | £5,260 sqm | £5,980 sqm | 686 |
Raw data
Our analysis of SL9 is derived from what is essentially a big table of sold prices from Land Registry with added property size information. Below are three rows from this table to give you an idea.
| Address | Paid | sqm | £/sqm |
|---|---|---|---|
| 4, Selman Way, | £820,000
Oct-2024
|
101 | 8,118 |
| 4, Chestnut Walk, | £885,000
Sep-2024
|
165 | 5,363 |
| 3, Denham Walk, | £831,000
Sep-2024
|
121 | 6,867 |
See the entire list of all sales in SL9 here.
About
I created HouseMetric because I wanted to see this data and analysis myself, I also wanted to teach myself to build a website. Please give me feedback or spread the word about it. I'm constantly tinkering and adding more stuff to it.