Converting a Viennese Altbau: Which Permits and Consents You Need, and in What Order

Who has a say in an Altbau conversion

In a conversion of a Viennese Altbau flat, several bodies can be involved. Not all are relevant to every project, but it helps to know them:

• Property management (Hausverwaltung): It knows the building, administers the shared parts and knows which rules apply in the house. It is usually the first port of call.
• Co-owners: In an owner-occupied flat they have a say when shared parts of the building or their own interests are affected.
• Landlord: In a rented flat, significant changes generally require his or her consent.
• Building authority (Baupolizei, MA 37): The City of Vienna's building authority is responsible when an intervention is relevant under building law, for instance with load-bearing elements.
• Structural engineer: He or she assesses whether and how an intervention in the load-bearing structure is possible, and provides the basis for many further steps.
• Other bodies: For listed buildings, in protected zones, with gas appliances or flue systems, additional bodies or specialists such as the chimney sweep may have to be involved.

For the couple on the Spittelberg, almost all of these bodies ended up involved, though not for every wish. The wall concerned structural engineering, co-owners and the building authority. The bathroom concerned mainly the property management because of the riser. The air-conditioning unit concerned the façade. Let us look at them one by one, starting with the co-owners.

Owner-occupied flats: the consent of the co-owners

Anyone who owns a flat may decide a great deal inside it. Limits arise where common parts of the building are touched or where the interests of other owners may be affected. These typically include load-bearing walls and ceilings, shared pipes and risers, shafts, chimneys and the façade.

In such cases the consent of the other owners generally has to be obtained. How this works in the specific building is something the property management knows. Sometimes a written consent is enough, sometimes the matter is dealt with at the owners' meeting. What matters is that the documents are easy to understand: a plan, a short description and, where necessary, a statement from the structural engineer.

Our experience is that co-owners rarely refuse on principle. They want to know whether their flat is affected, whether it will be loud and for how long. Anyone who informs openly makes consent easier.

Rented flats: the landlord has a say

In a rented flat the room for manoeuvre is narrower. For significant changes, for example to walls, pipework or plumbing installations, the landlord's consent is generally required. Also clarify what happens to the changes when you move out. A written agreement creates clarity for both sides. Then the authority has its own say.

Most consents fail not because of the substance but because of an unclear request.

The building authority: when MA 37 comes into play

Vienna's building code distinguishes, put simply, between projects that are possible without involving the authority, projects that must be notified to it, and projects that need a building permit. Which category applies depends on the specific intervention, and that is exactly what should be clarified before work begins.

As a rough guide: renewing surfaces, floors, tiles and sanitaryware in the same place is generally unproblematic under building law. Interventions in load-bearing elements, changes to the façade or to shafts, and changes in the use of individual rooms, on the other hand, may require the involvement of the building authority (MA 37). Whether a submission plan is needed and which documents go with it, we clarify case by case with the authority, the structural engineer and, where necessary, a civil engineer (Ziviltechniker).

For clients this above all means: build these steps into the schedule. Official procedures have their own deadlines, which cannot be shortened at will. How this fits into a realistic sequence is shown in the article on the timeline of a flat renovation. But why does the structural engineer so often come first?

Structural engineering: why the engineer often comes first

In a Viennese Altbau it is not always obvious at first glance which wall is load-bearing. Spine walls almost always carry load, but even seemingly light partitions can take loads, for instance because ceilings have settled over the decades. That is why any intervention in walls or ceilings begins with an assessment by a structural engineer.

The engineer checks the situation on site, assesses the load-bearing structure and, where possible, proposes a solution, such as a steel beam over a new opening. His or her statement is often the basis for the co-owners' consent and for the documents sent to the authority. What is possible when opening a load-bearing wall and what it means is explained in the article Removing a load-bearing wall in Vienna. How the open kitchen then succeeds is described in the article on the open-plan kitchen-living space.

With the couple on the Spittelberg, it turned out that the wall to the kitchen really did carry load. The solution was not a complete opening but a wide passage with a beam and a sliding glass door. The result feels more open than expected and was approvable with considerably less effort.

Imagine standing in the new wide passage. The beam is tucked into the edge of the ceiling, the sliding glass door is open, and the light from the kitchen window reaches the far wall of the living room.

A further advantage of an early structural assessment: it stops wishes becoming too specific before it is clear whether they are feasible. Anyone who learns only after the concept presentation that the planned opening is not possible loses time and often enthusiasm. That is why, for us, the structural engineer belongs in the site-survey phase, not in the detailed planning.

Skipping the clarifications has a price that rarely announces itself. A wish pursued without asking sends you back to the drawing board when the wall turns out to be load-bearing. A missing consent can stop a building site that has already begun. An unclear request is answered with a no. The weeks saved at the start are lost in the middle. And what about the outside of the building, with its own rules?

Listed buildings, protected zones and the façade

Many Viennese Gründerzeit buildings lie in protected zones, and some are listed. This affects above all the outward appearance: façade, windows, roof and visible building elements. Interiors are usually less affected in buildings in protected zones, whereas in listed buildings there can also be requirements inside, for example for stucco, doors or historic floors.

For clients this means: everything that has an effect on the outside needs particular care. An air-conditioning unit on the façade, new windows or an altered terrace may require additional consents. Whether a building is listed or lies in a protected zone can be clarified in advance, and the property management usually knows.

For the couple on the Spittelberg, the air-conditioning unit on the façade became a different solution: a unit with its outdoor part in the inner courtyard, agreed with the property management and the co-owners. What alternatives there are for pleasant temperatures is shown in the article Heating and cooling via surfaces.

Imagine a July afternoon in the finished flat. The air is cool, the façade looks as it always did from the street, and the only sound is the faint hum of the unit in the courtyard, out of sight.

Typical projects and who has a say

The following overview is a guide from practice, not a legal classification. In an individual case it may differ.

If you want to join two flats, further questions arise, for example on the land register situation and the owners' association. The article Combining two flats describes the planning side. And in what order do you proceed?

How to proceed: six steps

An orderly approach saves time and nerves. This sequence has proved its worth on our projects:

1. Collect and prioritise wishes. What should change? Which interventions are really necessary, which would be nice?
2. Check the existing structure. Survey, inspection of walls and pipework, assessment of which elements are affected.
3. Bring in the structural engineer. For any intervention in walls or ceilings, before planning what is not possible.
4. Inform the property management early. Clarify which consents are needed and how they are obtained in the building.
5. Prepare the documents. Plans, description, structural engineer's statement and, if needed, submission documents for the building authority.
6. Bring the neighbours along. A short notice or a personal conversation about duration and noisy phases often works wonders.

At Richard Atelier this preparation is part of the planning. We talk to the property management, the structural engineer and, where necessary, the authority, and prepare documents so that they are easy to understand. How this coordination is embedded in the project sequence is described in the articles Working with an interior designer and Planning and execution from a single source. The Team page shows who stands behind the planning. The Tischlerkultur joinery behind our planning has been family-run since 1935. The first conversation is free, lasts 30 minutes and takes place by phone or video, so you can find out where you stand before you spend anything.

Anyone who wins the property management over as an ally has already covered half the distance.