House prices in 'AL8 7', Welwyn Garden City

This article reveals price per square metre data and various charts to help you understand current housing market in 'AL8 7' (Welwyn Garden City) - statistics were last calculated on 16 October 2024.

Defining 'AL8 7'

This analysis is limited to properties whose postcode starts with "AL8 7", this is also called the postcode sector. There are no official postcode sector names so I've just labelled it AL8 7, Welwyn Garden City. 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 sector, or you can use the search form below.

Price per square metre

Knowing the average house price in AL8 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 July 2024, 40, Harwood Close, Welwyn Garden City, AL8 7SN sold for £365,000. Given the internal area of 57 square metres recorded on the EPC, the price per sqm is £365,000 ÷ 57 sqm = £6,403.

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 AL8 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 'AL8 7' vs 'AL8'

The chart above is called a histogram, it helps you see the distribution of house price per sqm in AL8 7 To make this chart we put all the sales data into a series of £ per sqm 'buckets' (e.g. £5,800 to £6,000, £6,000 to £6,200, £6,200 to £6,400 etc...) we then count the number of sales with within in each bucket and plot the results. The histogram is based on 109 sales that took place in AL8 7, Welwyn Garden City 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 AL8 7, Welwyn Garden City. Notably, only 25% of properties that sold recently were valued at more than £6,540 sqm. For anything to be valued more than this means it has to be more desireable than the clear majority of AL8 7 homes.


Box plot of £ per sqm for AL8 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. Welwyn Garden City. The chart above shows a boxplot for 'AL8 7' as well as the 'AL8' postcode district.

  • Median: The horizontal line inside the box represents the median (£ per square meter). This is the midpoint of the data, meaning 50% of the prices are below this value, and 50% are above. The middle price per square metre in 'AL8 7' is £5,630.
  • Interquartile Range (IQR): The box spans from the 25th percentile (Q1) to the 75th percentile (Q3). This is the range where the middle 50% of the data lies, giving a good indication of the typical price spread. Of the 109 transactions in AL8 7, Welwyn Garden City half were sold for between £4,830 and £6,540 per square metre.
  • Whiskers: In our case, the whiskers extend from the 9th percentile (at the lower end) to the 91st percentile (at the upper end), This provides a slightly broader view of the distribution by including the middle 82% of records. The whiskers capture most of the variation but exclude extreme outliers caused by data errors in recording sold house prices or internal area.
  • 'n=' is the number of property transactions the box plot is based on; 109 for AL8 7, Welwyn Garden City.
  • Property price map for Welwyn Garden City

    Have a look at the interactive price map I created for myself. Use it to explore 'AL8 7' house prices all the way down to individual property plots.

    Property price heatmap for Welwyn Garden City
    House price map for Welwyn Garden City

    Welwyn Garden City 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 AL8 7 (Welwyn Garden City) compared with the wider postcode district of AL8. You can extrapolate from this based on your own views on future interest rates, inflation and other factors.


    House price index for AL8 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 'AL8 7' property prices over the last 20 years. The index is calculated from the average price paid per sqm for property in AL8 7 and is set to 100 in 2004. I'm comparing the trends for AL8 7,Welwyn Garden City with the wider postcode district of AL8 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) – 1
    In 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 AL8 7
    AL8 7 sector AL8 district
    Nominal Real Nominal Real
    20 yr per annum 3.6% 0.9% 3.7% 1.0%
    20 yr total 102.1% 19.7% 106.9% 22.6%
    10 yr per annum 2.6% -0.2% 2.9% 0.1%
    10 yr total 29.1% -2.0% 33.6% 1.4%
    5 yr per annum 1.3% -2.7% 1.6% -2.4%
    5 yr total 6.4% -12.9% 8.2% -11.5%
    1 yr per annum -6.1% -9.9% -4.2% -8.0%
    1 yr total -6.1% -9.9% -4.2% -8.0%

    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, AL8 7 sector have seen a 0.9% annual change when adjusted for inflation. This translates to a total change of 19.7% in real terms.
    • Over the past 5 years, AL8 district have seen a -2.4% annual change when adjusted for inflation. This translates to a total change of -11.5% in real terms.

    Most recent AL8 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
    Haymeads, Welwyn Garden City, AL8 7A 70 sqm £4,087 12
    Great North Road, Welwyn Garden City, AL8 7T 90 sqm £5,137 11
    Harwood Close, Welwyn Garden City, AL8 7S 59 sqm £6,133 10
    Blakemere Road, Welwyn Garden City, AL8 7P 104 sqm £6,909 10
    Oakdale, Welwyn Garden City, AL8 7Q 87 sqm £5,258 9
    The Vineyard, Welwyn Garden City, AL8 7P 80 sqm £5,148 8
    Crossway, Welwyn Garden City, AL8 7E 111 sqm £5,177 8
    Ingles, Welwyn Garden City, AL8 7H 78 sqm £5,258 8

    Search for your street here.

    Nearby geographies

    The table below shows how 'AL8 7' compares to the other postcode sectors in AL8.

    Sector Lower quartile Median Upper quartile Sales in last 2yr
    AL9 5 Hatfield £4,430 sqm £4,970 sqm £6,170 sqm 81
    AL8 7 Welwyn Garden City £4,830 sqm £5,630 sqm £6,540 sqm 109
    AL8 6 Welwyn Garden City £5,230 sqm £5,890 sqm £6,840 sqm 123
    AL7 4 Welwyn Garden City £4,390 sqm £4,860 sqm £5,380 sqm 149
    AL7 3 Welwyn Garden City £4,330 sqm £4,760 sqm £5,350 sqm 181
    AL7 1 Welwyn Garden City £3,940 sqm £4,740 sqm £5,290 sqm 174
    AL6 9 Welwyn £4,570 sqm £5,310 sqm £5,960 sqm 112
    AL6 0 Welwyn £4,890 sqm £5,470 sqm £6,110 sqm 117
    AL4 9 St Albans £5,690 sqm £6,680 sqm £7,560 sqm 264
    AL4 8 Wheathampstead £5,580 sqm £6,210 sqm £7,050 sqm 122

    Raw data

    Our analysis of AL8 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
    40, Harwood Close, Welwyn Garden City £365,000
    Jul-2024
    57 6,403
    11, Greenfield, Welwyn Garden City £390,000
    Jul-2024
    76 5,131
    15, Cherry Croft, Welwyn Garden City £425,000
    Jun-2024
    83 5,120

    See the entire list of all sales in AL8 7 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.