Stefanie, you are an architect and interior designer. When and why did you pursue further training to become a Building Biology Consultant IBN?

During my studies, a building biology professional was invited to give special lectures and the topic resonated with me. When I started my career, I deliberately chose a firm that specialized in sustainable construction.

From 1999 to 2009, I was a co-owner of a larger firm. Initially, we built conventional masonry buildings, but gradually we added more and more sustainable wood frame buildings. Supervising the construction of these buildings is a sensory experience. The building materials, especially the wood, smell better. The buildings are dry, which creates an immediately pleasant indoor climate.

When we converted an old barn for my family, I knew right away that it should be sustainable. The fastest, most efficient, and healthiest approach was to build a house within a house using timber framing.

A colleague told me about the IBN training program. I completed the training part-time in the evenings in my converted barn. It felt like I was studying everything all over again, this time with a focus on building biology.

What interests you most about building biology?

Throughout history, humans have used building materials popular in building biology, such as clay, wood, stone, and straw. These materials form the basis of my work. Modern building technology continues to develop new materials based on these traditional ones to address complex moisture management challenges.

When did you establish your Building Biology Consulting Office IBN?

I worked in and around Paris for two years. Building biology was hardly a topic there. After returning in 2017, I wanted to make our architectural firm more visible as being rooted in building biology.

1 In my kitchen, for example, the cleaned stucco contrasts with the exposed walls and the simple, smooth furnishings.
2 Details of my office

You have worked in France and Germany. What are the main differences?

In France, architects tend to see themselves more as artists than engineers. My impression is that building culture and aesthetics are more important to them. However, they are less focused on sustainability.

What do you particularly value about working as an IBN consulting office?

With the IBN, I have a partner with strong technical expertise, as well as a warm and welcoming network. In my day-to-day work, hardly anything has changed. I design spaces for people who prioritize this topic, some more than others. I also advise people with health issues. After a long search, they ultimately discover the causes within their „building envelope.“

You are a member of the Chambers of Architects in North Rhine–Westphalia and Brandenburg. How does your work differ in the old and new federal states?

In North Rhine–Westphalia, the old buildings that needed renovation were mostly newer, built after World War II. Here in Brandenburg, the buildings are often from around 1900.

I work with the same regional tradespeople here and there whenever possible. In a small town, a good reputation is invaluable, so the tradespeople all make sure to deliver quality work at reasonable prices. This benefits the projects more than an extremely cheap contractor who disappears when problems arise. People who know each other and have built trust through collaboration also communicate more easily, which is a major advantage for the project. Things run much more smoothly and often faster. This, in turn, has a positive effect on costs.

One major difference is that less gets thrown away in those cases.

Older tradespeople who worked before the fall of the Berlin Wall tend to be more creative. They take the time to find and repair defects and search for replacement parts. This sometimes takes more time, but it’s more sustainable and reduces costs.

I like that the much smaller Brandenburg Chamber of Architects is more approachable than the one in North Rhine–Westphalia. There is also the Brandenburg Day of Sustainable Design and Building, a great event that we attend every year.

How important is your website to you?

Actually, we don’t need one. We rely on referrals. I’ve also been on Instagram for two years. There, I document my daily work life as if it were a diary. I share my impressions of what moves me and what makes me happy. I also offer a special glimpse into our construction sites. I direct younger people who want to get to know me there.

How much time do you spend on it, roughly?

Maybe 30 minutes a week. Sometimes I’ll do it on Sunday mornings at 7 a.m., coffee in hand, on the sofa.

What is your favorite project on Instagram?

Oh, there are two or three that stand out. One is a house right on the Havel River that was renovated according to the principles of building biology. We now rent it out to vacationers. Built in 1892, it was completely rundown with a checkered history. It was a stroke of luck to be able to buy it. My husband and I won the bid because we were the only ones who didn’t want to tear it down and build a four-unit apartment building in its place. Instead, we wanted to restore it to its original condition. That was important to the previous owners and makes the neighbors happy.

3 The vacation home on the Havel River before the complete renovation. The garage still had a pent roof and four extensions, all of which were later demolished.
4 Hand-colored drawing of the completed renovation.
5 The new west-facing facade makes a world of difference.
6 View of the west with the new terrace on the garage’s flat roof, new windows, shutters, and insulated roof.
7 The open kitchen is like an open workshop, open to all guests and their ideas.
8 The addition of the sunroom is a timber frame structure with outward-opening Danish windows.
9 The studio has a new bathroom and opens up to a wood fiber–insulated roof.
10 The furnishings were found, gifted, used, or discovered and then transformed. Vintage. Upcycling. Not like anywhere else. The only new items are the beds and the coffee machine.icht wie überall. Neu sind nur Dinge wie Betten und die Kaffeemaschine

That’s truly sustainable.

I recycled a lot and continued working with lime plaster. The furnishings were found, gifted, used, or discovered and transformed. The place has a down-to-earth feel and vacation guests find it charming and relaxing.

Where did you source the recycled building materials for your house?

Some were salvaged from the demolished extensions and others came from a Berlin dismantling and demolition contractor we often work with. He sends me photos whenever he needs to dispose of historic building materials, steel beams, floorboards, doors, or roof walkways. I then have the items refurbished and reworked. That’s how all the outdoor railings were reused. Using 18 m (59 ft) of material saves significantly on construction costs! I now have many sources and have become something of a hoarder, collecting materials for our other projects. For example, I have a colleague in Berlin who cuts up old bricks for me to use as flooring. The carpenters removed historic yet simple door handles in Berlin that were going to be thrown away – they fit perfectly in our house!

Who are your key partners?

We’re a small team of three: two civil engineers who specialize in structural engineering and building conservation and me. We also have a large network of regional tradespeople who appreciate old buildings and know how to work with them. This includes specialist engineers and architectural restorers. We also consider the building authorities and the historic preservation office to be our partners. Biofarben Berlin, a sustainable building materials supplier that has undergone further training at the IBN, is also an important partner of ours. We collaborate with an energy advisor who specializes in historic preservation and structural engineers who are comfortable working with old walls.

Since 2020, we have collaborated with the Department of Preservation and Construction Work in Structural Engineering at the University of Applied Sciences in Potsdam. To date, we have served as co-examiners for three theses. To ensure that the general public benefits as well, we have included the topic of a historic movie theater from 1940, among others.

Have current fluctuations in construction costs affected you?

Not really. We deal with them constantly here, of course, but we haven’t lost any projects because of them. It all calls for more creativity: „What can we save?“ We must find more ways to save money, such as recycling or omitting certain elements – less is more. However, this takes more time during the design stage and when explaining implementation. We also factor in higher safety margins when estimating costs. However, we almost exclusively work with old buildings. Our colleagues working on new builds are much more affected by this. They’re really struggling with it.

What are you and your team working on right now?

We have several projects in the works, ranging from an addition to a pony farm to renovating a doctor’s office. Next are eight complete renovations of houses built around 1900, three of which are historic landmarks. We are also converting a farm complex into apartments. In addition, we are retrofitting a semi-detached house built in 2002 to make it more energy-efficient for future generations.

I recently gave a tour of the historic island city, a designated historic conservation area, to a delegation from the Green Party. During the tour, I discussed our day-to-day design work and the challenges we face with projects in the area.

11 Conversion of a farm complex that is completely enclosed by four buildings surrounding a central courtyard
12 Kernsanierung und Ausbau des Dachgeschosses eines Denkmals
13 Renovation, furnishing, and conversion of a historic gatehouse into a vacation home
14 Application for a heritage conservation permit to convert the coach house of an organic farm, including consultation during construction
15 Inspiration for the interior design materials in an old building
16 Renovated bathroom with a steel bathtub and terrazzo flooring, enhanced with polished cement and a new color scheme
17 Kreatives Bad mit Kalkspachtel an der Wand, Regal aus einem Abriss und vom Installateur nach Vorgabe gebauter Heizung
18 Interior design for a gynecological practice in an old building

What is your vision for the future?

I want to breathe new life into existing buildings and showcase their potential for contemporary use. Perhaps my talent lies in helping people visualize what their old buildings can become. I inspire my clients to be creative with what already exists. I encourage them to retrofit it, expand it, rethink it, and see the building in a new light.

Thank you for the interview!