House prices in 'AL9 7', Welham Green
This article reveals price per square metre data and various charts to help you understand current housing market in 'AL9 7' (Welham Green, Brookmans Park) - statistics were last calculated on 03 December 2024.
Defining 'AL9 7'
This analysis is limited to properties whose postcode starts with "AL9 7", this is also called the postcode sector. There are no official postcode sector names so I've just labelled it AL9 7, Welham Green. It is shown in red on the map below.
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You can click on the map above to change to a neighbouring sector, or you can use the search form below.
Price per square metre
Knowing the average house price in AL9 7 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, Flat 1 Swan Lodge, Bell Lane, Welham Green, AL9 7AY sold for £385,000. Given the internal area of 63 square metres recorded on the EPC, the price per sqm is £385,000 ÷ 63 sqm = £6,111.
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 AL9 7 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 'AL9 7' vs 'AL9'
The chart above is called a histogram, it helps you see the distribution of house price per sqm in AL9 7 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 117 sales that took place in AL9 7, Welham Green, Brookmans Park 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 AL9 7, Welham Green. Notably, only 25% of properties that sold recently were valued at more than £7,040 sqm. For anything to be valued more than this means it has to be more desireable than the clear majority of AL9 7 homes.
Box plot of £ per sqm for AL9 7
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. Welham Green. The chart above shows a boxplot for 'AL9 7' as well as the 'AL9' postcode district.
Property price map for Welham Green
Have a look at the interactive price map I created for myself. Use it to explore 'AL9 7' house prices all the way down to individual property plots.
House price map for Welham GreenWelham Green house price forecasting
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 AL9 7 (Welham Green) compared with the wider postcode district of AL9. You can extrapolate from this based on your own views on future interest rates, inflation and other factors.
House price index for AL9 7
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 'AL9 7' property prices over the last 20 years. The index is calculated from the average price paid per sqm for property in AL9 7 and is set to 100 in 2004. I'm comparing the trends for AL9 7,Welham Green with the wider postcode district of AL9 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 Welwyn Hatfield 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 AL9 7
| AL9 7 sector | AL9 district | |||
|---|---|---|---|---|
| Nominal | Real | Nominal | Real | |
| 20 yr per annum | 3.4% | 0.7% | 3.3% | 0.7% |
| 20 yr total | 95.2% | 15.6% | 93.2% | 14.4% |
| 10 yr per annum | 2.7% | -0.1% | 2.8% | 0.0% |
| 10 yr total | 30.0% | -1.3% | 32.3% | 0.5% |
| 5 yr per annum | 1.6% | -2.4% | 2.1% | -1.9% |
| 5 yr total | 8.2% | -11.4% | 10.9% | -9.2% |
| 1 yr per annum | -8.8% | -12.5% | -3.2% | -7.1% |
| 1 yr total | -8.8% | -12.5% | -3.2% | -7.1% |
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, AL9 7 sector have seen a 0.7% annual change when adjusted for inflation. This translates to a total change of 15.6% in real terms.
- Over the past 5 years, AL9 district have seen a -1.9% annual change when adjusted for inflation. This translates to a total change of -9.2% in real terms.
Most recent AL9 7 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 |
|---|---|---|---|
| Brookmans Avenue, Welham Green, AL9 7Q | 286 sqm | £8,122 | 17 |
| Georges Wood Road, Welham Green, AL9 7B | 183 sqm | £6,782 | 14 |
| Moffats Lane, Welham Green, AL9 7R | 173 sqm | £6,857 | 13 |
| Westland Drive, Welham Green, AL9 7U | 104 sqm | £6,613 | 13 |
| Bell Lane, Welham Green, AL9 7A | 131 sqm | £5,956 | 12 |
| Bradmore Way, Welham Green, AL9 7Q | 156 sqm | £6,703 | 11 |
| Mymms Drive, Welham Green, AL9 7A | 262 sqm | £7,308 | 11 |
| Holloways Lane, Welham Green, AL9 7N | 116 sqm | £5,498 | 11 |
Search for your street here.
Nearby geographies
The table below shows how 'AL9 7' compares to the other postcode sectors in AL9.
| Sector | Lower quartile | Median | Upper quartile | Sales in last 2yr |
|---|---|---|---|---|
| EN6 3 Potters Bar | £5,210 sqm | £6,290 sqm | £7,270 sqm | 80 |
| EN6 1 Hadley Wood | £4,580 sqm | £5,760 sqm | £6,540 sqm | 132 |
| AL9 7 Welham Green | £4,950 sqm | £5,790 sqm | £7,040 sqm | 117 |
| AL9 6 Essendon | £4,920 sqm | £6,110 sqm | £7,250 sqm | 21 |
| AL9 5 Hatfield | £4,380 sqm | £4,960 sqm | £5,810 sqm | 82 |
| AL4 0 St Albans | £5,600 sqm | £6,500 sqm | £7,320 sqm | 228 |
| AL2 1 London Colney | £4,520 sqm | £5,130 sqm | £5,970 sqm | 162 |
| AL10 9 Hatfield | £3,920 sqm | £4,430 sqm | £5,000 sqm | 172 |
| AL10 8 Hatfield | £3,940 sqm | £4,420 sqm | £4,750 sqm | 137 |
Raw data
Our analysis of AL9 7 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 |
|---|---|---|---|
| Flat 1 Swan Lodge, Bell Lane, Welham Green, Brookmans Park | £385,000
Oct-2024
|
63 | 6,111 |
| 46, Pooleys Lane, Welham Green, Brookmans Park | £450,000
Oct-2024
|
118 | 3,813 |
| 20, Pine Grove, Welham Green, Brookmans Park | £1,750,000
Sep-2024
|
248 | 7,056 |
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.