Retail Assessment Note
| Stantec UK Limited 7 Soho Square London W1D 3QB UNITED KINGDOM |
30 June 2025 Project: 333102403
PROPOSED CO-OP FOOD STORE, STATION ROAD, PORT ERIN RETAIL ASSESSMENT NOTE
Introduction
- 1. This note has been prepared on behalf of the Co-op in order to inform development proposals subject to Planning Application 24/91051/B comprising a co-op foodstore, 6 tourist apartments above, and associated car parking.
- 2. Drawing on the Isle of Man Census Report (2021) and Household income and Expenditure Survey (2018/19), this Note examines the capacity for additional retail floorspace in Port Erin, before considering the likely impacts on existing stores and centres. It then considers more broadly whether the proposals have an adverse effect on retail areas as the policy test in the Isle of Man Strategic Plan Policy 9 requires.
Background Context
- 3. The application site lies on the corner of Station Road and Droghadfayle Road. Within the Southern Area Plan, the site is designated as an area for civic, cultural and other uses. It is a contiguous part of the mixed-use Port Erin centre area to the south and west, with residential and tourism uses to the east and north. While the site is technically located outside of the village centre, it is clearly well connected to the central area being within walking distance of existing centre facilities.
- 4. The Strategic Plan and the Area Plan acknowledge that the southern and western areas have the greatest requirement for additional convenience supermarket type development and recommends that such development should focus on main settlements such as Port Erin or Castletown (paragraph 6.22).
- 5. Within the UK, there is generally a floorspace threshold of 2,500 sq m (gross) before a retail assessment is required, given the perceived limited impact of stores below this threshold. In Policy 9 of the Isle of Man Strategic Plan, this threshold is set at 500 sq m. The proposed store has a gross area of 464 sq m (5,000 sq ft) so would be below this threshold requirement. This retail assessment has therefore been undertaken as a relatively high-level exercise, to be proportionate to the scale of the proposal, to assist in considering the effects of the proposals on the existing service centre.
- 6. The proposed store will stock a range of convenience goods items. The retail assessment has therefore only considered convenience goods trading and expenditure and not assessed the impacts on the comparison goods sector.
Proposed Store Turnover
- 7. The expected turnover of the proposed co-op store has been based on the latest Global Data (Dec 2024) analysis of business sales densities, even though it is expected that the proposed store would trade below average given the presence of the existing small Co-op store within the centre. The use of this data will therefore ensure a robust assessment of impacts. As Port Erin is a holiday destination on the Island, it has also been assumed that 15% of turnover of the store will be derived from tourists and visitors to the store that do not live locally.
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Table A1: Proposed Store Turnover
| Gross Floorspace (sq m)<br><br> | Net Sales (sq m)<br><br> | Sales Density (£per sqm) (2024 prices)<br><br> | Sales Density (2022 prices)<br><br> | Turnover (£) (2022 prices)<br><br> | Turnover derived from Catchment (85%)<br><br> |
| 464.5 | 325.15 | £11,898 | £10,230 | £3,326,427 | £2,827,463 |
Notes
- 1. Net sales derived as 70/30 ratio
- 2. Sales converted into 2022 prices to allow comparison with Mannin Retail retail work (July 2024)
Retail Capacity – Convenience Goods
- 8. We have calculated a resident population catchment using the 2021 Isle of Man Census Report for the southern village and parishes of Port Erin, Port St Mary, Arbory and Rushen. We have then forecast the population to increase by 0.9% over 5 years based on the existing trend (Table A2). The latest Isle of Man Population Report 2024 further supports the use of this trend showing similar pro-rata growth in the period 2021-2024 and acknowledging that the South is a key destination for new and returning residents (second only to Douglas). Table A2: Estimated Area Population
| Port Erin | Rushen | Arbory | Port St Mary | Total |
| Population 2021 | 3,730 | 1,661 | 1,899 | 1,989 | 9,279 |
| Population Projection 2026 | 3,764 | 1,676 | 1,916 | 2,007 | 9,363 |
| Population Projection 2031 | 3,797 | 1,691 | 1,933 | 2,025 | 9,447 |
| Population Projection 2036 | 3,832 | 1,706 | 1,951 | 2,043 | 9,532 |
Notes
- 1. Population 2021 derived from Census data
- 2. Population increase at 0.9% per 5 year period.
- 9. To calculate available expenditure, we have used the Isle of Man Household Income and Available Expenditure Survey (2018/19) to determine expenditure per household per week on convenience goods. This amounts to £97.69 (see Appendix 1 of Report – includes: food and non-alcoholic drinks; alcohol and tobacco; detergents, washing-up liquids, washing powder; disinfectants and polishes; kitchen foil, bin bags, kitchen rolls; matches and firelighters; cloths; newspapers and magazines). This has then been converted into per capita expenditure per annum using the average household size of 2.22 (2021 Census) and projected forward in 2022 prices using the Experian Retail Planner Briefing Note 22 (March 2025).
Table A3: Per Capita Convenience Goods Expenditure
| Year | Expenditure per Head (2022 prices)<br><br> |
| 2019 | £2,562 |
| 2020 | £2,726 |
| 2021 | £2,688 |
| 2022 | £2,565 |
| 2023 | £2,490 |
| 2024 | £2,463 |
| 2025 | £2,458 |
| 2026 | £2,453 |
| 2027 | £2,451 |
| 2028 | £2,448 |
| 2029 | £2,446 |
| 2030 | £2,443 |
| 2031 | £2,441 |
| 2032 | £2,438 |
| 2033 | £2,436 |
| 2034 | £2,436 |
| 2035 | £2,436 |
| 2036 | £2,436 |
Notes
- 1. Expenditure per head in 2019 - £2,288 in 2019 prices; £2,562 in 2022 prices
- 2. Expenditure projected forward using Appendix 3 of Experian Retail Planner 22
- 3. Figures may not cast due to rounding.
- 10. For the purposes of this assessment, we have not made any deductions for Special Forms of Trading (internet shopping and expenditure spent in vending machines etc). For convenience goods, spending via the internet tends to originate from existing stores and therefore this expenditure should not be protected. (Businesses such as Ocado do not operate in the Isle of Man).
- 11. In summary it is estimated that there is c£23m of convenience goods expenditure in the area, rising to c£23.2m in 2036. Table A4: Estimated Available Convenience Goods Expenditure
| Total Estimated Expenditure (2022 prices) |
| 2026 | £22,965,975 |
| 2031 | £23,057,037 |
| 2036 | £23,218,044 |
Notes
- Table A2 x Table A3
- 12. Not all of that expenditure is available to support the new store. The existing turnover of stores needs to be considered in working out any surplus of expenditure to support new developments.
- 13. In order to do this, we have used the data from the Mannin Retail application for the ‘Redevelopment of the Airport Garage’ in Ballasalla. Table A5 provides a summary of the turnover predictions for Port Erin, Port St Mary and Colby, which are situated within our defined catchment area. We have then adjusted the turnovers by 10% to recognise that not all the store turnovers will be derived from within our catchment). Table A5: Convenience Goods Turnover derived from Catchment (based on 2027 assessment)
| Location | Size (net sales area) (Sq m)<br><br> | Turnover 2026 (2022 prices)<br><br> | Turnover from Catchment (90%) |
| | | |
| Port Erin | | | |
| Tesco | 937 | £10.93m | £9.84m |
| Co-op | 311 | £3.44m | £3.10m |
| Others (inc. Spa) | 196 | £1.91m | £1.72m |
| | | |
| Port St Mary | | | |
| Co-op | 72 | £0.38m | £0.34m |
| Others | 55 | £0.25m | £0.23m |
| | | |
| Colby | | | |
| Convenience (Spa) | 55 | £0.34m | £0.31m |
| | | |
| Total | | £17.25m | £15.53m |
Notes
- 1. Data from Table 2.5 of Mannin Retail Application (Retail Impact Assessment) July 2024
- 2. Figures for 2027 Assessment to be used at 2026 base year
- 3. Figures may not cast due to rounding.
- 14. On the basis that the total turnover of convenience stores being derived from the catchment is £15.53m, it can be demonstrated that there is additional capacity to support new convenience goods floorspace. Table A6 provides a summary of surplus expenditure within the catchment. Table A6: Existing Available Expenditure to support new floorspace.
| Available Expenditure | Surplus expenditure |
| 2026 | £22,965,975 | £7,440,975 |
| 2031 | £23,057,037 | £7,532,037 |
| 2036 | £23,218,044 | £7,693,044 |
Notes
- 1. Table A4 – A5
- 2. Figures may not cast due to rounding.
Proposed Store – Trade Draw and Impacts
- 15. The available expenditure capacity to support a new convenience store is important context but the new store will still draw trade from existing stores and potentially have an impact on centres as a result of this.
- 16. In order to consider impact, a relatively simple trade draw analysis has been undertaken in Table A7. This takes forward the existing trading picture set out in Table A5 and allocates 50% of the surplus expenditure to stores based on their market share (i.e. suggests a degree of overtrading at stores above benchmark levels given available expenditure). The remaining 50% is assumed to be spent outside of the catchment (i.e. leakage).
- 17. The turnover of the proposed Co-op is then introduced and judgements made about where this turnover will be derived from. A large proportion of the turnover (55%) is expected to be drawn from Tesco as the only major convenience store in the area. Conversely, smaller proportions are expected to be drawn from Port St Mary and Colby as these stores generally operate as top up facilities and if customers wanted a larger range of goods like would be offered in the proposed Co-op, they are already likely to use the Tesco.
Table A7: Trade Draw Assessment 2026
| Location | Benchmark Turnover | Turnover from Catchment | Market share | Adjusted Turnover | Trade Draw (%) | £ Draw | Resultant Turnover | % Benchmark |
| | | | | | | | |
| Port Erin | | | | | | | | |
| Tesco | £10,930,000 | £9,837,000 | 63.4% | £13,287,387 | 55.0% | £1,555,105 | £11,732,282 | 107.3% |
| Co-op | £3,440,000 | £3,096,000 | 19.9% | £4,181,941 | 25.0% | £706,866 | £3,475,075 | 101.0% |
| Others | £1,910,000 | £1,719,000 | 11.1% | £2,321,950 | 6.0% | £169,648 | £2,152,302 | 112.7% |
| | | | | | | | |
| Port St Mary | | | | | | | | |
| Co-op | £380,000 | £342,000 | 2.2% | £461,959 | 2.0% | £56,549 | £405,409 | 106.7% |
| Others | £250,000 | £225,000 | 1.4% | £303,920 | 1.0% | £28,275 | £275,645 | 110.3% |
| | | | | | | | |
| Colby | | | | | | | | |
| Convenience | £340,000 | £306,000 | 2.0% | £413,331 | 1.0% | £28,275 | £385,057 | 113.3% |
| | | | | | | | |
| Other (Leakage) | | | | £3,720,487 | 10.0% | £282,746 | £3,437,741 | 92.4% |
| | | | | | | | |
| New Co-op | | | | | | £2,827,463 | £2,827,463 | |
| | | | | | | | |
| Total | £17,250,000 | £15,525,000 | 100.00% | £24,690,975 | 100.0% | | £24,690,975 | |
- 18. In conclusion, Table A7 shows impacts on the existing stores are limited, with all existing stores maintaining a turnover above benchmark level. Accordingly, the quantitative impact on the centres of Port Erin and Port St Mary is unlikely to be significant and the health of these centres would not be adversely affected.
Assessment of Effects on Adjacent Retail Areas
- 19. The Application site lies outside of the defined mixed-use area of Port Erin centre. However, the site is designated for services - civic, cultural and other uses – that one would expect to find in central areas. The site is therefore considered a contiguous part of the Port Erin centre area and within walking distance of existing facilities and the proposals would support the wider services of the centre.
- 20. Port Erin central area remains vital and viable providing a wide range of services and facilities. As the Area Plan notes, there are some vacant units (the former Little Shoprite is an example) but these constitute a small proportion, and the overall character is lively. The vacant units are not of sufficient scale to provide an alternative to the proposals either.
- 21. There have also been some recent investments in the centre, with refurbishment of the Falcon’s Nest hotel and Tesco’s occupation of Shoprite. Site 21 of the Area Plan to the south of the Tesco (previously used as an overflow for parking) is also being resurfaced to provide more formal parking.
- 22. The range of shops available in the centre will not be adversely affected by the Co-op proposals. The shops predominantly provide a range of comparison goods, which will not be stocked by the proposed Co-op store. The few convenience stores - Spar (within the Petrol Station), the Mannin Retail Post Office store (Church Road) and the Good Health Store (Health Food) on Station Road serve a specific function and the Co-op would not be expected to compete more directly with them than the existing Co-op store does.
- 23. Drawing our analysis together, we consider there to be expenditure capacity to support the Co-op proposals without adversely affecting the trading of existing stores in the centre. It is also considered that Port Erin centre is vital and viable and the proposals would not undermine this status given the range of services and stores provided, many which stock comparison goods that the Co-op will not provide.
- 24. The new store would provide a large range of convenience goods to provide competition and choice with the Tesco, and help to retain more expenditure in the local area. Its location within walking distance of
- the central area will ensure it supports other facilities in the centre (through linked trips) and further investment.
- 25. Accordingly, it is concluded that the proposals would not have an adverse effect on adjacent retail areas and would therefore accord with Strategic Policy 9.
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