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Free! Foundation Depth Calculator app Work out correct foundation depths when building near trees

Foundation calculator screens

The NHBC Foundation Depth Calculator app is designed to help you calculate the correct foundation depths when building near trees. It's available FREE on iOS, Windows OS and Android.

Portable, detailed and fast technical calculations

The Foundation Depth Calculator gives you an effective field-based tool to help assess tree types (via third party apps) and required NHBC Standards Chapter 4.2 foundation depths on your mobile phone, handheld device or PC. It's the perfect app to confirm required foundation depths when building near trees in clay soil.

The app allows for changes in ground level, the input of an unlimited number of trees and an auto climate zone depth reduction function via GPS. It also advises on suitable heave precautions, if needed, and which tree(s) require them to be provided.

Read more technical information

Reducing foundation related claims

Foundation related claims have cost the industry more than £36 million over the last 4 years. This new app will assist in reducing the number and cost of foundation-related claims and in turn raise standards and improve homeowner satisfaction.

Get the Foundation Depth Calculator now!

The app is free to NHBC registered builders and professional subscribers to NHBC Standards.

Stage 1 - Download the app

  • To download the iOS version, please go to the App Store
  • To download the Windows OS version, please go to the NHBC Extranet (details below).
  • To download the Android version, please go to the Google Play Store

Stage 2 - Activate the app

  • To activate the app, you'll need to log on to the NHBC extranet and gain the onetime installation username and password, this is different to your extranet username and password, simply follow the instructions below.

Already have an Portal account?

  • Log in to your account
  • Select Technical Standards
  • Download the Windows Version
  • Retrieve the username/password for the app

Sign-up for a FREE Portal account

  • Sign-up for a FREE account - we only need a few details to get you started
  • Once you have your login details, login and select Technical Standards to retrieve the app username/password

Any questions?

Please don't hesitate to contact us on  


Any questions?

For more information call us on
01908 747384 or email us

Example Screenshots

Click on a thumbnail to see example screens.

Site Details Site Details

Tree Selection Tree Selection

Heave Details Heave Details