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Reporting an article error

Include the page address, the passage or diagram you are concerned about, and a supporting source if you have one. Our editorial standards explain how corrections are reviewed.

Reporting a calculator problem

Describe what you expected and what happened. Include the units, relevant wall and trim measurements, fixture positions, selected window modes and the steps that produced the result. A screenshot and your browser/device details can help us reproduce it.

If you choose to send a downloaded project file, check its project name and measurements first and remove anything you do not want to share. Do not include your home address, passwords, payment details or other sensitive information.

Project-specific questions

We can clarify how the site and calculator work. We cannot inspect your wall through the tool or confirm a site-specific installation, fixing method or electrical arrangement. Those questions may need someone qualified to assess the actual conditions.