LOCATION

AL3 7AW - Flood, Heat, Air & Subsidence Risk - Trowley Bottom (AL3)

Dacorum, Trowley Bottom (AL3)

Flood: Very lowHeat: MediumAir quality: MediumGround: Low

Climate risk summary for AL3 7AW

AL3 7AW in Trowley Bottom (AL3) has a Very low flood risk - EA NaFRA2 data records no properties in a flood risk zone in this postcode. Heat risk is Medium, with a median (50th percentile) of 29 days above 25°C per year, averaged over the 2021-2040 period under the RCP8.5 high emissions scenario (Met Office UKCP18). Air quality is Medium at PM2.5 7.3 μg/m³, above the WHO annual guideline of 5 μg/m³ (Defra UK-AIR). Ground conditions are Low risk, with Colluvium geology; shrink-swell risk is classed as improbable (BGS GeoClimate).

How does AL3 7AW compare with the rest of the UK?

  • Air pollution: more polluted than 70% of councils
  • Heat risk: hotter than 70% of councils
  • Subsidence risk: lower risk than 58% of postcodes
  • Green space access: better green access than 89% of English postcodes

What is the flood risk in AL3 7AW?

Flood risk at AL3 7AW is rated Very Low, based on Environment Agency NaFRA2 modelling.

Environment Agency flood zone data shows very low flood risk for AL3 7AW in Trowley Bottom (AL3). EA NaFRA2 data shows no properties at flood risk in this postcode. The band reflects the highest flood risk within the postcode; some properties within this postcode may face little or no direct flood risk. For a specific property, a conveyancing search will confirm the exact flood zone position.

What is the heat risk in AL3 7AW?

Heat risk at AL3 7AW is rated Medium, reflecting Met Office UKCP18 climate projections (50th percentile) for this area, averaged over the 2021-2040 period under the RCP8.5 high emissions scenario. These are probabilistic projections - the 50th percentile is the central estimate within RCP8.5; the full range of modelled outcomes is wide and lower emissions scenarios would produce lower figures. Higher summer temperatures increase cooling energy costs, affect comfort in poorly insulated or south-facing properties, and can accelerate shrinkage in clay soils beneath foundations. Properties built before 1980 without cavity wall insulation are typically most affected.

How is the air quality in AL3 7AW?

Air quality at AL3 7AW is rated Medium, based on Defra UK-AIR annual mean PM2.5 data. Fine particulate matter (PM2.5) comes primarily from road traffic, industry, and domestic burning. Long-term exposure above the WHO guideline of 5 µg/m³ is linked to respiratory and cardiovascular health risks. Buyers and renters in higher air quality risk areas may wish to consider whether the property is near busy roads or industrial sources.

Is subsidence a risk at AL3 7AW?

British Geological Survey data classes the underlying soil at AL3 7AW as Colluvium, with shrink-swell hazard rated improbable (subsidence risk band: Low). A structural survey is the reliable way to assess ground conditions for a specific property.

Where does this data come from?

This LocalRisk report for AL3 7AW draws on four official UK open data sources: Environment Agency NaFRA2 flood modelling, Met Office UKCP18 climate projections, Defra UK-AIR PM2.5 monitoring, and British Geological Survey GeoClimate subsidence mapping. Risk ratings are a screening tool, complementing - not replacing - the searches and surveys ordered as part of a property transaction. Data covers Dacorum and is updated as new official datasets are published.

About the Dacorum area

Dacorum has a mixed town and rural setting across chalk hills and river valleys and experiences cool, wet winters and warm summers, influenced by elevation and drainage patterns.

What should buyers and renters check in AL3 7AW?

Practical check: With 29 hot days projected (UKCP18 50th percentile, 2021-2040 average under RCP8.5), note which bedrooms face west (hottest in evening) and whether windows allow through-ventilation. With PM2.5 above WHO guidelines here, check which bedrooms face busy roads and how fresh air is drawn into living spaces. These are postcode-level indicators - conditions vary between individual properties.

Climate risk can change street by street, so it is worth checking neighbouring postcodes too. The full risk report for AL3 4AA is at localrisk.co.uk/postcode/AL34AA, and you can compare AL3 7AW side by side with any UK postcode at localrisk.co.uk/compare.