Analysing the existing building before a conversion: why LPH 1 decides between success and consequential damage in old buildings
In existing buildings, planning never starts on a greenfield site. Every building brings its own history, quirks and hidden risks. Surprises come with an old building. They only become expensive when they appear too late. In service phase 1 (LPH 1, basic evaluation) of the German fee scale for architects (HOAI), assumptions become reliable facts, and that is precisely what makes this phase so decisive for every conversion and refurbishment project in Wiesbaden and the Rhine-Main region.
A thorough analysis of the existing building is the first and most important step in any project involving an old building. It creates the basis for all further planning steps and prevents decisions from being based on incomplete information. fbnSTUDIO has guided clients through this phase for many years and knows from experience: anyone who invests here saves in the end.
What is a building analysis for an old building?
A building analysis for an old building is the systematic recording and assessment of the existing building fabric. It covers the documentation of the structural condition, the identification of risk zones and the clarification of the starting position under building law. Within the framework of the HOAI, it corresponds to service phase 1 (basic evaluation), in which the client's objectives are compared with the actual conditions of the building. For clients in Wiesbaden and the surrounding area, it is particularly relevant, because a large part of the building stock dates from the Wilhelminian era (Gründerzeit) or the post-war decades and therefore has its own specific structural characteristics.
Why is LPH 1 different in existing buildings compared with new builds?
Old buildings and listed buildings have different build-ups and materials and a different moisture behaviour from new builds. Existing drawings are often incomplete. Earlier conversions frequently remain invisible: rerouted services, bricked-up openings, concealed layers, hidden damage. What is clearly defined in a new build has to be found out first in an existing building.
In addition, the load-bearing structure of an existing building cannot be altered without taking the overall structural engineering into account. Whereas in a new build every wall, every floor and every opening is planned from the ground up, an existing building has to be worked with as it stands. That calls for a deep understanding of the existing construction and for planning that responds to the building, not the other way round.
What does the basic evaluation clarify in concrete terms?
In existing buildings, LPH 1 creates clarity before money flows into the design, bids and the building site. Specifically, the following questions are answered:
- Which building components exist and how are they constructed?
- Where are the risk zones, for example with moisture, cracks, timber components, the roof or the basement?
- Which building services exist and in what condition are they?
- What are the client's objectives regarding use, comfort, energy and budget?
- What is the starting position under building law, particularly for listed buildings?
The result is a reliable basis for decisions that brings everyone involved to the same level of knowledge. This considerably reduces planning errors, change orders and construction delays.
Why do small inspection openings save large costs?
Targeted inspection openings at critical points, for example at the plinth, at roof junctions or at timber beam floors, provide information that neither an existing drawing nor a visual inspection can replace. They make the actual condition of the construction visible before the planning builds on it.
In practice this means: an architect who exposes the beam ends of a timber beam floor before the design stage will detect rot or insect infestation early. Without this opening, the damage would only become visible during construction, when trades have already been commissioned and materials ordered. The consequences would be construction delays, change orders and higher overall costs. Inspection openings are a comparatively small investment that creates planning certainty and avoids later surprises.
Building analysis for listed buildings in Wiesbaden
In Wiesbaden, numerous buildings are listed, from Wilhelminian-era town villas and historic commercial buildings to post-war buildings of particular architectural significance. For these buildings, it must already be clarified in the basic evaluation which components are protected: façade, windows, staircase, interior fittings or entire room structures.
Without this early clarification, planning goes in the wrong direction. Clients who only learn about the scope of protection during the design process lose time and have to re-plan. In heritage protection, coordination with the responsible authority is not an optional step but a mandatory prerequisite for realistic planning that can be approved. More on this in our article on working with the heritage authority.
The most common mistakes in analysing the existing building
In practice, typical mistakes keep appearing that lead to problems later in the planning process. The most common mistake is omitting a systematic building survey altogether. Some clients rely on existing plans and assume that they correctly reflect the current condition. With buildings that are several decades or even centuries old, this is almost never the case.
Another common mistake is an analysis that is too superficial. A purely visual check is not enough to detect hidden defects. Moisture in basement walls, damage to timber components behind cladding or outdated service routes in shafts only become visible through targeted investigations. Anyone who leaves out these investigations in the basic evaluation shifts the risk into the construction phase, where it becomes considerably more expensive.
The third typical mistake concerns the lack of involvement of specialist planners. Depending on the type and condition of the building, it may be necessary to involve structural engineers, building physicists, hazardous-substance surveyors or specialist planners for building services early. Anyone who brings in this expertise only during construction loses time and risks planning conflicts.
How does an analysis of the existing building work at fbnSTUDIO?
At fbnSTUDIO, every project involving an existing building begins with a structured initial consultation, in which the client's objectives, the existing documents and the first framework conditions are recorded. This is followed by a systematic site inspection, in which the building is documented from outside and inside. Structural features, visible damage, traces of moisture and the existing building services are recorded.
In the next step, existing drawings are compared with reality and, where necessary, corrected or redrawn. If required, we recommend targeted inspection openings or the involvement of specialist consultants. The result is a report on the existing building with a risk assessment, which serves as the basis for all further planning steps. For listed buildings, we clarify the scope of protection in parallel and contact the responsible heritage authority early.
This structured approach has proved its worth on numerous projects in Wiesbaden and the Rhine-Main region. Whether it was the cultural monument on Viktoriastraße, the change of use of a commercial building in Montabaur or the complete refurbishment of a detached house in Limburg: the analysis of the existing building was the cornerstone of successful implementation in each of these projects.
Buying an old building: why a building analysis makes sense before the purchase
Increasingly often, prospective buyers turn to architects before they acquire a property. A professional assessment of the structural condition before the purchase decision can prevent hidden defects from only becoming visible after the notary appointment (the signing of the purchase deed). In this case, the building analysis provides a basis for decision-making: can the building be refurbished? Which interventions can be foreseen? What cost range can a refurbishment or conversion be expected to fall within?
For buyers in Wiesbaden and the surrounding area, this preliminary check is particularly relevant, because the regional property market is still shaped by existing buildings with considerable refurbishment needs. A sound assessment by an experienced architect protects against bad purchases and provides certainty when planning the financing. This applies in particular to Wilhelminian-era buildings in Wiesbaden's city centre, which are architecturally appealing but may have a considerable need for action in structural and energy terms.
What does a building analysis by an architect cost?
The costs of a building analysis depend on the size of the building, the complexity of the existing fabric and the level of investigation required. A flat-rate figure would therefore not be credible. What is decisive is that the investment in a sound basic evaluation is small in comparison with the costs that undetected defects can cause during the construction phase.
Typical services within a building analysis include the site inspection with systematic documentation, the evaluation of existing documents, the preparation or checking of existing drawings, the identification of risk areas and a first assessment of feasibility and cost framework. Where necessary, specialist planners for structural engineering, building physics or hazardous-substance investigations are brought in. At fbnSTUDIO, clients receive a transparent summary of the results after the basic evaluation, with clear recommendations for the next steps.
Can costs be calculated reliably for existing buildings?
Reliable cost estimates are only possible for existing buildings once a sound basis is available. Before that, all figures are merely rough guide values. Clients who calculate on the basis of a complete building analysis have considerably fewer change orders and more realistic project planning than those who skip this step.
The most common cost increases in projects involving existing buildings do not arise from unforeseeable events, but from risks that could have been recognised early. A building analysis makes these risks visible and assessable before the design begins.
Check the existing building before the list of measures: the most sensible first step
Anyone who wants to convert, refurbish or change the use of a building in Wiesbaden or the Rhine-Main region should not begin with a list of measures, but with a systematic building analysis. A clear risk assessment with concrete next steps creates planning certainty and protects against wrong decisions.
Experience shows that projects that start with a solid basic evaluation run more predictably, stay closer to budget and achieve better results. This applies to the refurbishment of a detached house just as much as to the change of use of a listed building. Service phase 1 is not a formality but the foundation for responsible and economically viable planning for existing buildings.
Book an initial consultation with fbnSTUDIO. We will analyse your existing building, identify risks and develop a reliable basis for your conversion or refurbishment in Wiesbaden and the surrounding area.
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