Is a site diary mandatory? HOAI, contracts and BG BAU

Start by identifying the purpose of the record

A construction progress record explains what happened, when and in which area. It can bring together progress, contractors, deliveries, weather, notable events and unresolved questions. A private-helper record captures work time for a different reporting and contribution purpose. One document may contain information relevant to both without necessarily being complete for either.

First establish who needs which information from you. Is it agreed construction supervision, a contractor’s contractual report, your own project overview or a BG BAU return? Then decide the content, format, recipients and filing process.

What HOAI actually says about a site diary

For buildings and interiors, HOAI Annex 10.1 lists documentation of construction progress in service phase 8, item e, giving a site diary as an example. That wording describes a documentation service. By itself, it does not require every person on every site to use a particular form or app.

For a specific commission, check which services the contract includes and how the records must be handed over. References to HOAI service phases, additional specifications and reporting requirements can matter. Resolve uncertainty about contractual scope; a downloadable form cannot interpret the agreement for you.

Site manager, contractor and construction client

For a person commissioned to supervise the works, documentation forms part of the agreed service. A contractor may separately maintain daily reports, time records or work records. Those documents do not necessarily share the same purpose or content.

As the construction client, you may keep your own chronological overview. Separate your observations from statements supplied by contractors. Your diary does not replace the agreed services of the appointed supervisor. Equally, establish before work begins which reports you will receive and in what format.

Private construction: helper-hour records for BG BAU

BG BAU explains notification, information and record-keeping duties for private construction projects. Required information includes helper hours. It provides its own diary aid and explains reporting through the Eigenbaunachweis. Use that official guidance for your circumstances.

The key distinction is that a general progress and weather report does not replace complete helper-hour records. Equally, a helper-hour list does not necessarily document construction progress. Our diary template focuses on progress and is not an official BG BAU form.

What a useful daily record should contain

Choose the scope from the purpose of your records. For practical collaboration, clear locations, specific activities and verifiable references are usually more useful than lengthy standard wording. Write so that somebody who was not present can understand the recorded state.

• Project, date, period covered and person recording the information.
• Areas and work performed, with a clear description of progress.
• Relevant contractors, deliveries, meetings and notable events.
• Weather observations with time and source where relevant to the work.
• Deviations, unresolved questions and references to separate notices.
• Clearly attributed photos and attachments, with dated corrections.

Fictional example: observations before conclusions

Entirely fictional example: “13 October 2026, 08:10, roof area north: standing water is visible. The planned activity had not started at the time of the visit. The contractor’s representative reports a postponed start; the cause and impact on the programme remain to be agreed. Photos T-021 to T-023.”

This wording separates visible conditions, third-party information and unresolved questions. Saying that a contractor is in delay because of bad weather would mix several unverified conclusions. A diary entry does not itself determine responsibility or entitlement to payment or an extension of time.

If a separate contractual notice, decision or approval is required, handle it through the agreed process and reference it in the diary. Merely adding an entry does not make an unsent notice an effectively delivered communication.

Paper, Excel or an app: define the workflow

Choose the tool according to scale, participants and the agreed handover. An Excel template may be sufficient for individual daily records. With many entries and parallel documentation, reliable assignment to the project and date, and retrieving the right version, become important.

Whatever the tool, decide who adds information, who checks it, how photos are linked and when a version is shared. Identify later additions. An ordinary PDF export is a saved version, but does not by itself provide tamper-proof archiving or a qualified timestamp.

A short daily routine

Collect your observations and clearly attributed reports, update outstanding issues, check the attachments and retain the required report version. Add later information as a dated addition. This avoids records that appear contemporaneous but were actually reconstructed from memory weeks later.

Set retention and access rights according to contractual and organisational requirements. The name “site diary” does not establish a universal retention period. Record personal information only where necessary for your purpose and share the documentation with the intended recipients.