Bauwerksbuch Section 128a: Deadlines, Content, Electronic Record

For a Vienna property manager (Hausverwaltung), the Bauwerksbuch (the statutory building logbook) is no longer a new concept, but the deadline logic still trips people up: new builds are affected immediately, existing buildings have staggered deadlines running to 2027 and 2030, and the duty to keep the record electronically lands wherever a Hausverwaltung is appointed — with the Hausverwaltung, not automatically with the owner. The legal basis is Section 128a of the Vienna Building Code, readable in full on RIS — a Vienna state regulation, not a federal law.

Who may prepare the Bauwerksbuch, what drives the cost and which checklist serves as a template is covered in Vienna Bauwerksbuch: Preparer and Cost Drivers.

New builds: before the completion notice

Section 128a(2) of the Vienna Building Code requires a Bauwerksbuch, prepared by an independent qualified party, before the completion notice is filed for new builds, additions and conversions. Kleingartenhäuser, Kleingartenwohnhäuser and buildings with a built-up area of 50 m² or less are exempt. For a project nearing completion, the Bauwerksbuch is therefore not an optional add-on afterward — it belongs among the documents that must be in place before the completion notice.

Existing buildings: two deadlines, no third

For existing buildings, Section 128a(3) sets two deadlines:

• by 31.12.2027 for buildings erected before 1.1.1919;
• by 31.12.2030 for buildings erected between 1.1.1919 and 1.1.1945.

Both categories of Bauwerksbuch must be registered in the City of Vienna's Bauwerksbuch database from 1.7.2024 (Section 128a(3), Section 128c). For a Hausverwaltung with a mixed portfolio, that means concretely: the pre-1919 stock runs toward 2027 first, the interwar stock toward 2030 — two separate deadlines, not one shared one.

For buildings erected after 1.1.1945, Section 128a(3) names no first-time deadline. An obligation can still arise from a later addition or conversion (Section 128a(2)), or from an authority order in a justified individual case. For most postwar buildings in a Hausverwaltung's portfolio, that means no automatic date — but no permanent exemption either, once construction work happens.

A portfolio example

A Hausverwaltung with thirty Vienna properties usually has a mix of construction years in practice, and the deadlines do not run in sync. Take twelve pre-1919 buildings, eight interwar buildings (1919–1945), and ten postwar properties. The twelve pre-1919 buildings hit their deadline first — by 31.12.2027 each needs a Bauwerksbuch prepared and registered in the database. The eight interwar buildings have until 31.12.2030. For the ten postwar properties, as long as no addition or conversion is planned, there is currently no statutory deadline for first-time preparation — which does not mean they are permanently outside the rule, only that the obligation is tied to a future building project or an authority order in an individual case.

The practical point for a manager with a mixed portfolio: the twelve pre-1919 buildings need attention first, not because they are "older and therefore more urgent" in a general sense, but because Section 128a(3) specifically assigns them the earlier deadline.

Who keeps it, and how

This is the point that matters most for a Hausverwaltung. Section 128a(5) states: "Das Bauwerksbuch ist von der Eigentümerin oder vom Eigentümer, wenn für das Gebäude eine Hausverwaltung bestellt ist von dieser, in elektronischer Form zu führen und der Behörde auf Verlangen zur Einsicht zur Verfügung zu stellen" — the Bauwerksbuch must be kept in electronic form by the owner, or, where a Hausverwaltung is appointed for the building, by the Hausverwaltung, and made available to the authority for inspection on request. Where a Hausverwaltung is appointed, the ongoing electronic-keeping duty therefore falls to it — not to the owner alone, and not as a one-time creation but as continuous record-keeping that must be accessible to the authority on request.

That is a different duty from the registration under Section 128a(3): database registration covers existing buildings against the two deadlines; the electronic-keeping duty under Section 128a(5) covers the Bauwerksbuch itself, whether it originated from the new-build or the existing-building case.

For a Hausverwaltung appointed across several properties, that adds up to an ongoing task rather than a one-off: per building, one electronically kept Bauwerksbuch, available for inspection on request at any time, regardless of when the document itself was originally prepared.

What has to be in it

Section 128a(5) says who keeps the Bauwerksbuch. Section 128a(4) says what belongs in it. The content revolves around the Abs. 1 inspection duty — building components whose deterioration could endanger life or health — not a general building file. Concretely, the Bauwerksbuch must contain:

• the building's construction permits and completion notices or occupancy permits;
• the designation of the building components subject to regular inspection;
• the timing of the first inspection and the intervals of subsequent inspections;
• the qualifications the inspecting persons must meet;
• the results of inspections carried out, excluding inspections required for components under other federal or state legislation;
• a current record of any defects found and a plan to remedy them;
• documentation of measures or changes under Section 118c(2) and (7).

That is the complete list under Abs. 4 — no more, no less. A Hausverwaltung should not quietly extend it to ownership records or general building-services documentation: the statute ties the content to the Abs. 1 inspection duty, the permit history, and the Section 118c cross-reference.

The three exemptions

Section 128a(2) lists three exemptions from the Bauwerksbuch requirement: Kleingartenhäuser, Kleingartenwohnhäuser, and buildings with a built-up area of 50 m² or less. Those are exactly the categories the text names — a Hausverwaltung should not read this more broadly than the text supports, for instance by treating small outbuildings or garages as exempt across the board without actually checking their built-up area.

What the law does not cover

Three things sit outside the Vienna Building Code that a Hausverwaltung should not confuse with this requirement:

• Section 128a is Vienna state law, not a federal Austrian statute. It applies within Vienna and does not automatically apply in other provinces.
• The law sets no deadline for first-time preparation for buildings built after 1945 — a Hausverwaltung that assumes one on its own goes beyond the text.
• The Bauwerksbuch itself is prepared by an independent qualified party (Section 128a(2)) — the Hausverwaltung keeps it current, it does not replace the independent party that prepares it.

What Unitify contributes, and what it doesn't

Unitify keeps the building documentation a Bauwerksbuch needs — documents and an asset register — continuously current, instead of assembling it under deadline pressure. That is the concrete task a platform plays in this context: keeping documents, deadlines and responsibilities visible and findable per building, so the 2027 and 2030 dates don't arrive as a surprise.

Unitify is not a Bauwerksbuch within the meaning of Section 128a and does not prepare one. It does not replace the independent party that prepares the Bauwerksbuch under Section 128a(2), or the authority that reviews it. What the platform handles is the day-to-day documentation work for the Hausverwaltung — preparation itself remains a professional service outside the software.

If the Bauwerksbuch deadlines for your portfolio are getting closer than the documentation you have ready for them, book a demo to see how the documentation stays current on an ongoing basis.