House prices in 'SA4 9', Penllergaer

This article reveals price per square metre data and various charts to help you understand current housing market in 'SA4 9' (Penllergaer, Gorseinon) - statistics were last calculated on 01 November 2024.

Defining 'SA4 9'

This analysis is limited to properties whose postcode starts with "SA4 9", this is also called the postcode sector. There are no official postcode sector names so I've just labelled it SA4 9, Penllergaer. 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 SA4 9 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 September 2024, 37, Llyn Tircoed, Penllergaer, SA4 9LB sold for £365,000. Given the internal area of 112 square metres recorded on the EPC, the price per sqm is £365,000 ÷ 112 sqm = £3,258.

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 SA4 9 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 'SA4 9' vs 'SA4'

The chart above is called a histogram, it helps you see the distribution of house price per sqm in SA4 9 To make this chart we put all the sales data into a series of £ per sqm 'buckets' (e.g. £2,450 to £2,500, £2,500 to £2,550, £2,550 to £2,600 etc...) we then count the number of sales with within in each bucket and plot the results. The histogram is based on 152 sales that took place in SA4 9, Penllergaer, Gorseinon 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 SA4 9, Penllergaer. Notably, only 25% of properties that sold recently were valued at more than £2,950 sqm. For anything to be valued more than this means it has to be more desireable than the clear majority of SA4 9 homes.

Box plot of £ per sqm for SA4 9

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. Penllergaer. The chart above shows a boxplot for 'SA4 9' as well as the 'SA4' 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 'SA4 9' is £2,620.
  • 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 152 transactions in SA4 9, Penllergaer half were sold for between £2,290 and £2,950 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; 152 for SA4 9, Penllergaer.

    • Property price map for Penllergaer

    Have a look at the interactive price map I created for myself. Use it to explore 'SA4 9' house prices all the way down to individual property plots.

    Property price heatmap for Penllergaer
    House price map for Penllergaer

    Penllergaer 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 SA4 9 (Penllergaer) compared with the wider postcode district of SA4. You can extrapolate from this based on your own views on future interest rates, inflation and other factors.

    House price index for SA4 9

    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 'SA4 9' property prices over the last 20 years. The index is calculated from the average price paid per sqm for property in SA4 9 and is set to 100 in 2004. I'm comparing the trends for SA4 9,Penllergaer with the wider postcode district of SA4 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 Swansea 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 SA4 9
    SA4 9 sector SA4 district
    Nominal Real Nominal Real
    20 yr per annum 2.5% -0.1% 3.0% 0.3%
    20 yr total 65.1% -2.2% 79.9% 6.5%
    10 yr per annum 3.9% 1.1% 4.5% 1.7%
    10 yr total 46.8% 11.4% 56.0% 18.5%
    5 yr per annum 6.1% 1.9% 6.1% 1.9%
    5 yr total 34.2% 9.9% 34.3% 9.9%
    1 yr per annum -3.1% -7.0% 2.6% -1.5%
    1 yr total -3.1% -7.0% 2.6% -1.5%

    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, SA4 district have seen a 0.3% annual change when adjusted for inflation. This translates to a total change of 6.5% in real terms.
    • Over the past 5 years, SA4 district have seen a 1.9% annual change when adjusted for inflation. This translates to a total change of 9.9% in real terms.

    Most recent SA4 9 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
    Gorseinon Road, Penllergaer, SA4 9A 115 sqm £1,912 19
    Y Llanerch, Penllergaer, SA4 9D 94 sqm £2,590 16
    Ffordd Y Meillion, Penllergaer, SA4 9F 95 sqm £2,633 12
    Home Farm Way, Penllergaer, SA4 9H 141 sqm £2,753 12
    Swansea Road, Penllergaer, SA4 9E 110 sqm £1,934 11
    Elm Crescent, Penllergaer, SA4 9Z 80 sqm £2,417 10
    Heol Y Twyn, Penllergaer, SA4 9E 70 sqm £2,114 9
    Mansion Gardens, Penllergaer, SA4 9G 126 sqm £2,617 9

    Search for your street here.

    Nearby geographies

    The table below shows how 'SA4 9' compares to the other postcode sectors in SA4.

    Sector Lower quartile Median Upper quartile Sales in last 2yr
    SA5 7 Penlan £1,520 sqm £1,790 sqm £2,170 sqm 88
    SA5 5 Ravenhill £1,430 sqm £1,790 sqm £2,120 sqm 93
    SA5 4 Fforestfach £1,590 sqm £2,130 sqm £2,470 sqm 114
    SA4 9 Penllergaer £2,290 sqm £2,620 sqm £2,950 sqm 152
    SA4 8 Pontarddulais £1,590 sqm £1,920 sqm £2,500 sqm 182
    SA4 6 Loughor £1,740 sqm £2,160 sqm £2,680 sqm 155
    SA4 4 Gorseinon £1,630 sqm £1,950 sqm £2,490 sqm 306
    SA4 3 Gowerton £2,060 sqm £2,460 sqm £2,930 sqm 207
    SA4 0 Hendy £1,610 sqm £2,300 sqm £2,650 sqm 101

    Raw data

    Our analysis of SA4 9 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
    37, Llyn Tircoed, Penllergaer, Gorseinon £365,000
    Sep-2024
    		 112 3,258
    8, Pontardulais Rd, Penllergaer, Gorseinon £270,000
    Aug-2024
    		 126 2,142
    47, Heol Y Waun, Penllergaer, Gorseinon £292,000
    Aug-2024
    		 101 2,891

    See the entire list of all sales in SA4 9 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.