Transitions between old and new affect whether an extension feels coherent. Differences in height, material and structure should be visible early.
What the drawing needs to explain
Create a defect map with photographs, locations and investigation questions. Include inspection access and the intended drainage path in the repair proposal.
Coordinate finished levels
Compare floor levels, ceilings, thresholds and the garden. Include layers still to be added, not just rough construction dimensions.
Design hidden junctions
Structure, weather protection, insulation and finishing meet at the connection. The trades should use the same detail.
How to review the result
Check the repair and future access together. Ask which signs deserve attention at the next inspection and where the relevant documentation is stored.
Which trade-off matters?
Completely concealing a junction may look attractive but make later inspection harder. Compare a closed finish with a solution keeping vulnerable points accessible.
A situation to test your plan against
Timber and masonry can show damage where the materials meet. Record moisture traces or deformation first. A new finish does not help when the underlying cause remains unclear.
Questions for your own property
- Are finished heights known?
- Who designs the junction?
- How are material differences handled?
Is concealing damage enough for a lasting repair?
Investigate the cause first. Then agree repairs, inspection and maintenance access; without that coordination, a neat finish can conceal a recurring problem.
Illustrative design situations, not evidence of completed work. Assess decisions against the actual property.