Project note
About The Marked Door
An independent practical resource for recording door measurements, assumptions and setting-out marks before work begins.
Independent guide
What it covers
The Marked Door is built for UK homeowners, landlords and small trades who need a legible worksheet beside a real door job. It makes the arithmetic visible, keeps entered assumptions with each result and provides a printable record.
The initial proving worksheet records three widths and three heights for either an existing slab or a frame opening. Later material must meet the same rule: explain what is calculated, what is merely recorded and when the tool must stop.
What it does not claim
This resource does not inspect a property, certify an installation, select a door, establish structural adequacy or replace the documentation supplied for a particular doorset. No invented author biography, trade credential, testimonial or company history is used as proof.
Tool-hire link disclosure: two task-specific guides contain clearly labelled commercial links to Mammoth Hire where a reader may need to compare equipment. The Marked Door does not sell or hire tools, and a link is not a suitability recommendation.
Corrections
Formulae, versions, boundaries and research dates are kept in the methodology register. External references appear once in the source register, with the date they were accessed. A correction should change the relevant register and the worksheet together.
Project statement version 1.1.0 ยท 4 September 2026