---
path: industries/retail
title: Retail
desc: Find the homes with no supermarket within 1 km.
date: Oct 21, 2026
---

# Find the neighbourhoods no supermarket serves

Grocery expansion teams look for homes with no store within reach. This example finds every residential building in Lisbon more than 1 km from a supermarket, from OpenStreetMap.

## Lisbon homes more than 1 km from a supermarket

**Data:** OpenStreetMap supermarkets, mapped as points or outlines, and residential buildings
**Method:** keep residential buildings with no supermarket within 1 km, measured on the ellipsoid

```sql
-- Residential buildings with no supermarket within 1 km
WITH supermarkets AS (
  SELECT geom FROM osm.shop_point
  WHERE  osm_type = 'shop' AND osm_subtype = 'supermarket'
    AND  geom && ST_MakeEnvelope(-9.28, 38.66, -9.05, 38.82, 4326)
  UNION ALL
  SELECT ST_Centroid(geom) FROM osm.shop_polygon
  WHERE  osm_type = 'shop' AND osm_subtype = 'supermarket'
    AND  geom && ST_MakeEnvelope(-9.28, 38.66, -9.05, 38.82, 4326)
)
SELECT b.osm_id, b.osm_subtype AS building, b.geom
FROM   osm.building_polygon AS b
WHERE  b.osm_type = 'building'
  AND  b.osm_subtype IN ('apartments', 'residential', 'house', 'semidetached_house', 'terrace', 'detached', 'dormitory')
  AND  b.geom && ST_MakeEnvelope(-9.25, 38.68, -9.08, 38.80, 4326)
  AND  NOT EXISTS (
         SELECT 1 FROM supermarkets AS s
         WHERE  s.geom && ST_Expand(b.geom, 0.013)
           AND  ST_DWithin(b.geom::geography, s.geom::geography, 1000)
       );
```

The supermarket search runs a little wider than the homes, so a shop just over the city edge still counts.

```map
lisbon-homes-far-from-supermarkets
```

## Run it on your data

Upload your own stores, or your competitors', as a spreadsheet and swap them in for the `supermarkets` step to see which homes none of them reach. Change `1000` to test another distance. See [spreadsheets](/docs/upload-anything/spreadsheets).


## Frequently asked questions

**Does a gap mean a good site?**

Not by itself\. Distance is one input\. Demand needs data this example does not include\.

**Is the 1 km measured along streets?**

No, in a straight line\. Distance along streets needs a road network and a different method\.


## Next step

- [Open the map in the gallery](/gallery?industry=retail)
- [Upload your store list](/docs/upload-anything/spreadsheets)
- [Learn the SQL behind it](/docs/spatial-sql-book)
- [Book a demo](/demo)