Gather the structure and alteration history
Prepare plans, accessible photographs, previous reports and information on roof changes. Identify the future use and any new equipment or openings. Mark areas that cannot be inspected safely or are concealed. A drawing of the intended room does not explain how existing loads are supported or whether the proposed changes are feasible.
Request a project-specific inspection
Ask the relevant professional to explain the scope of observation and investigations. Discuss the condition of members, connections and supports as well as signs of water. Keep uncertainty explicit when an area remains inaccessible. Do not infer soundness or a need for replacement from surface appearance alone, and do not remove a member to test an assumption.
Have new loads and modifications assessed
Include insulation, linings, equipment and the proposed use of the space. Discuss roof windows, access and any structural changes with the appropriate designer. The roof structure and the floor below are separate parts to consider. This guide does not provide a member-size rule or authorise a cut, opening or reinforcement for the building.
Coordinate structural work with weather protection
Clarify who prepares the design, carries out the work and checks its implementation. Coordinate covering, temporary protection, insulation and services. Ask how concealed connections and supports will be recorded before other trades close them. Agree how discoveries change the scope, cost and programme rather than treating an allowance as automatic approval.
Retain final references and inspection information
Keep the agreed design, documented changes and useful photographs with the final building file. Record what has been repaired, replaced or left with a stated limitation. Request instructions relating to future access or maintenance where appropriate. A completed finish should not erase the history needed for later investigations or alterations.
Your preparation checklist
- Structure and changes described.
- Inspection scope defined.
- Unknown areas identified.
- Loads and alterations assessed.
- Weather protection and interfaces assigned.
- Final information retained.
Questions before you commit
Can a roof member be removed because it blocks a room layout?
Have the alteration designed and justified before any removal. This page cannot establish the role of a particular member.
Does assessing the roof structure confirm the loft floor?
The floor and its supports need to be considered for the proposed use as well.
Sources and the scope of this guide
This English guide covers the same project need as its French counterpart, with an editorial explanation in English. It is not a professional survey or a translation of foreign rules to France. Check current official requirements and the documents applying to your building and contract.
French reference: AQC : déformations des charpentes en bois
French reference: AQC : humidité des enveloppes et ossatures bois