Magazine
MAGAZIN
It’s time for Carl
#greenbuilding

It’s time for Carl

May we introduce Carl? Using timber for its facade besides the supporting structure, the apartment block is currently under construction in Pforzheim. Architect Peter W. Schmidt explains how this is being done.

Pforzheim is also known as the gateway to Germany’s Black Forest. It has wood literally on its doorstep, a raw material that is readily available. While woodlands are disappearing in other parts of the world, in Central Europe – including Germany – overall they are increasing. This is due to sustainable forestry, which has been practised here for centuries. Arlinger Building Cooperative has calculated that the quantity of wood required for its high-rise project named Carl regrows across Germany in less than five minutes.

Carl, timber high-rise, Pforzheim
The quantity of wood required for the high-rise named Carl regrows across Germany in under five minutes.

Timber construction centre stage in the Black Forest

With the aim of pressing ahead with modern, climate-friendly timber construction, a few years ago the German state of Baden-Württemberg placed timber construction centre stage and now presents a timber construction award every year. Ever since the state’s building regulations were amended in 2014, timber construction projects up to the height of a normal high-rise have been permitted here. Although building with timber is no longer especially innovative when it comes to detached houses, plyscrapers – another name for timber high-rises – are new territory.

Regional history and an affinity with wood as a material are returning to the centre of attention.

Peter W. Schmidt, architect

The developers in Arlinger – a district of Pforzheim – are therefore working with an expert in engineered timber construction from Bregenz Forest. Any specific issues that arise can be additionally clarified in consultation with a research institute. The apartment block was planned by architect Peter W. Schmidt. He highlights the regional significance of the project, which will reach a height of 38 metres: “Regional history and an affinity with wood as a material are returning to the centre of attention. At the same time, the project acts as sustainable stimulus to counteract the shortage of housing.”

High-tech construction material

The timber used for plyscrapers is a compact high-tech construction material that is in no way inferior to conventional construction methods that use concrete and steel. Equivalent engineered timber elements display a high load capacity with a low weight.

Carl, timber hybrid, Pforzheim
The supporting structure and external facade of this timber hybrid building are both planned with timber.

As numerous fire safety tests have already confirmed, this modern constructional timber achieves excellent fire protection results. It is crucial that the structure is maintained in the case of fire, allowing residents enough time to leave the building.

Timber facade

Around 2,000 m³ local wood are expected to be required for Carl, which will consist of over 80% timber. This 14-storey high-rise is a timber hybrid construction, and will therefore include concrete as reinforcement. In most cases, like with Carl, reinforced concrete is used for the building core with the staircase.

Besides the supporting structure, the facade will also be made of timber, which is unusual for timber high-rise buildings. The storeys are separated by a wide brim that extends out beyond the facade to protect it from the weather. “Thanks to a one-metre cantilevered brim designed to prevent fire flashover, the cladding can also be made of timber,” the architect explains.

Energy efficient and sustainable

The excellent insulation properties of wood were discovered long ago. This high-rise, named Carl after Arlinger founder Carl Hölzle, will be an energy-efficient house according to KfW standard 55. The figure signifies that only 55% of the energy used by a conventional, comparable building is required. Its sustainability concept includes underground car parking spaces with chargers for electric cars. A photovoltaic system on the roof will supply green energy for future tenants.

Terasse, Carl, timber hybrid, Pforzheim
The upper floors overlook Arlinger and the neighbouring Black Forest.

In addition to the 14-storey Carl, the plans include two more sections with four and six storeys. Overall, Arlinger building cooperative will be creating 73 apartments here, with a total area of over 5,300 m². Childcare facilities and a bakery with adjoining café will also be on offer. The building cooperative is convinced of the benefits: “Together with the neighbouring buildings, Carl and the entire ensemble will create a compelling aesthetic and act as a landmark at the entrance to the town.”

Second-tallest timber high-rise in Germany

Ground was broken for this timber construction project in October 2021. Prefabricated timber parts were fitted between February and October 2022, and completion is scheduled for November 2023. The tower block Roots in Hamburg is due to be finished in 2023 as well. And so it seems that the race for the title “Germany’s tallest timber high-rise” will be won by Carl’s rival from northern Germany, which will eclipse Carl by an extra 27 metres.

Text: Gertraud Gerst
Translation: Rosemary Bridger-Lippe
Visualizations: PWS Architekten

Other articles
that might interest you

The circular office
#smart office
The circular office

Impact Hub Berlin is a community and coworking space that has taken recyclable construction from theory to practice. LXSY Architekten used timber construction and recycled building materials for the interior design in a converted old warehouse.

Old method stages a comeback
#greenbuilding
Old method stages a comeback

One hundred years after patenting of the Zollinger roof, this self-supporting timber structure is experiencing a renaissance. Designed to save materials, recyclable and easy to build, it has regained popularity for the construction of today’s factory workshops.

Copenhagen as the world’s first net-zero capital city
#city planning
Copenhagen as the world’s first net-zero capital city

Copenhagen is fast approaching its goal of achieving carbon neutrality. Its former city architect Camilla van Deurs, recently appointed head of the Nordic Office of Architecture's new specialist area for strategic urban development, spoke to ubm magazine. about the biggest levers for reducing carbon emissions.

The supermarket of the future
#greenbuilding
The supermarket of the future

A supermarket designed as a net-zero construction that produces its own food for the region. This is the concept behind Rewe Green Farming and its prototype in Wiesbaden, Germany. Timber engineering is central to the company’s plan for similar stores.

Alpine architecture at its best
#greenbuilding
Alpine architecture at its best

The recent rebuild of Voisthaler Hut in Austria’s Hochschwab Mountains uses structural timber design with sophisticated architectural and ecological features. This energy self-sufficient mountain hut designed by Dietger Wissounig Architekten has been awarded the “Umweltgütesiegel” and also won the 2023 BIG SEE Architecture Award.

A metro station built with timber
#city planning
A metro station built with timber

Although this design looks like a utopian dream, in Copenhagen it is set to become reality. Over the coming years, the Danish capital will be introducing timber-hybrid metro stations. The concept by JaJa Architects adopts a holistic approach and takes climate-friendly building below ground.

Logistics centre opts for wood
#greenbuilding
Logistics centre opts for wood

Not far from Amsterdam, fashion giant Bestseller is building Europe’s largest timber logistics centre – called “Logistics Center West”. Designed by Danish architects Henning Larsen, it aims to set new standards in sustainability and design.

Mediating between mountain and valley
#greenbuilding
Mediating between mountain and valley

Its design blends alpine architecture with the outline of a craggy mountain range. The Congress and Exhibition Centre in the municipality of Agordo in northern Italy reimagines aesthetic forms of expression in timber construction.

A Zen-style home
#living
A Zen-style home

The Belgian city of Antwerp will soon benefit from a Japanese-inspired, timber-hybrid residential tower that is currently under construction. The building was designed by Pritzker Prize winner Shigeru Ban, who takes nature and wood as central inspiration for his designs.

Flourishing in a residential greenhouse
#living
Flourishing in a residential greenhouse

Bremen’s Überseeinsel district is a new, green neighbourhood currently under development. Affordable, sustainable and attractive living space will be on offer in the Residential Greenhouse. It is designed to be a home for both people and plants.

New schools from construction kits
#greenbuilding
New schools from construction kits

There is a severe shortage of schools – 15,000 are needed in Europe alone. The easy-to-assemble kit from Stora Enso – called Sylva – can be used to create eco-friendly wooden schools that offer children a positive learning environment and architecture that gives them a sense of meaning and purpose.

The woman behind Henning Larsen
#architecture
The woman behind Henning Larsen

CEO Mette Kynne Frandsen has worked for over 20 years to make Danish architectural firm Henning Larsen what it is today: a pioneer in creating sustainable yet iconic architecture around the world. She gave us an interview before leaving her position.

Sustainability with the power of two
#greenbuilding
Sustainability with the power of two

Architectural firm Pittino & Ortner based in Styria, Austria, is making a name for itself on two fronts: with its huge timber-hybrid book storage facility in Vienna and its café on Lake Thalersee near Graz.

On track for transformation
#greenbuilding
On track for transformation

Industrial wastelands need new strategies to present workable options for re-use. The architects at Smartvoll are experts in this kind of development. One of their designs is an ecosystem for the former railway depot in Amstetten, Lower Austria, as living space for plants, animals and people.

A church that stores carbon
#architecture
A church that stores carbon

As the first church to be built in Copenhagen for 30 years, it may well become an icon. Ørestad Church is a sculptural timber construction designed by Henning Larsen. A kind of “Church 2.0”, it is also a modern community centre that reaches out to everybody regardless of their belief.

Wisdome shows pioneering expertise
#greenbuilding
Wisdome shows pioneering expertise

One of the world’s most spectacular timber engineering projects was recently completed in Sweden. Built for Stockholm’s Tekniska Museet, the Wisdome is a free-form structure using 20 kilometres of laminated veneer lumber. The design uses this kind of wood in an entirely new way.

Alpine lodges redeveloped
#hotel
Alpine lodges redeveloped

MoDus Architects have restructured a hotel complex that has decades of growth behind it. The external space created by a new layer of timber on the outside of the Icaro Hotel brings together the existing buildings to form a uniform whole. On the inside, guests encounter plenty of affectionate references to Alpine clichés.

Inspired design for heavenly wines
#architecture
Inspired design for heavenly wines

The fine wines from Château Angélus winery are now also produced in Libourne, France. Its new wine cellar designed by Eric Castagnotto looks like a church nave, which is probably no coincidence.

Glamping in hilltop chalets
#hotel
Glamping in hilltop chalets

A luxury campsite at the foot of Vorarlberg’s Rätikon mountain range has been enlarged, with the addition of ten timber tiny houses. These hilltop chalets are a reinterpretation of the Alpine hut, and their design has won several awards.

Timber construction by star architect
#hotel
Timber construction by star architect

The first five-storey hotel in mass timber design is located in Zillertal, Austria, created by celebrated Italian architect Matteo Thun. It is no coincidence that one of the leading players in structural timber construction is based only a stone’s throw away.

The transformer hotel
#hotel
The transformer hotel

VALO is the name of a complex on the outskirts of Helsinki that combines hotel accommodation with office facilities. With a dual use that is both efficient and viable, the beds are folded away during the day, making way for fold-out desks.

Timber showcase for Volvo
#greenbuilding
Timber showcase for Volvo

A special kind of discovery world is taking shape in Gothenburg, where Swedish vehicle manufacturer Volvo is using timber construction and nature to create its World of Volvo. The components and engineering for Henning Larsen’s design are being provided by Austrian firm Wiehag.

Wave of the future
#greenbuilding
Wave of the future

The Klimatorium in Lemvig, Denmark, devises strategies to counteract global climate change. Situated on the coast of Jutland, the building designed by architects 3XN has already achieved iconic status.

A bridge to the future
#greenbuilding
A bridge to the future

As Dusseldorf’s Theodor Heuss Bridge needs a complete overhaul, the team at RKW Architektur + put their heads together – and produced a spectacular new design. It is literally packed with potential.

Yes to Jess!
#city planning
Yes to Jess!

The town of Jessheim is getting an impressive new centre. Designed by Norwegian firm Mad arkitekter, it promises to combine sustainable urban development with attractive indoor and outdoor areas.

New life among the mushrooms
#architecture
New life among the mushrooms

Metropol Parasol has achieved a phenomenal rejuvenation of a neglected square in Seville. The iconic timber construction by J.MAYER.H architects is a prime example of successful intervention in public space.

Blueprint for forests in urban living
#city planning
Blueprint for forests in urban living

The Forestias is one of the largest property development projects in Thailand. The highlight of this project by Foster + Partners is a 48,000 m² urban forest designed by TK Studio.

Timber high-rise with guaranteed recycling
#greenbuilding
Timber high-rise with guaranteed recycling

The Kajstaden Tall Timber Building in Sweden marks the beginning of a new generation of mass timber blocks. Using this building material saves around 500 tonnes of CO₂, and it also facilitates deconstruction later on.

Now that’s rocket science
#greenbuilding
Now that’s rocket science

There’s a rocket preparing to launch in Switzerland. The residential timber high-rise named Rocket in Winterthur’s Lokstadt neighbourhood will reach a height of 100 metres. The tower’s residents will be part of the 2000-watt society.

A school with the hygge factor
#greenbuilding
A school with the hygge factor

Kautokeino skole in northern Norway is a project that seeks to embrace the uniqueness of Sami culture and educational style. The mass wood building is so hygge, you’ll want to check in for a few nights.

Cabins in the Lyngen Alps
#architecture
Cabins in the Lyngen Alps

If you love the far north, you’ll love the Lyngen Alps. And if you love the Lyngen Alps, you’ll love the bungalows by architect Snorre Stinessen.

Superblock designed with mass timber
#city planning
Superblock designed with mass timber

Canada’s megaproject Waterfront Toronto includes a new district called Quayside, an all-electric and climate-neutral community. Its highlights are a two-acre urban forest and the residential Timber House by architect David Adjaye.

Where the future is radically car-free
#city planning
Where the future is radically car-free

The city of San Diego in Southern California has plans for a new district, one that will be entirely void of cars. Known as Neighborhood Next, it must be one of the most radical projects in the USA.

Climate neutral and affordable
#city planning
Climate neutral and affordable

The new urban quarter Zwhatt near Zurich is designed to enable climate-neutral living at affordable prices. One of its buildings is a 75-metre-high timber hybrid tower known as Redwood, whose facade generates solar power.

Wood with superpowers
#greenbuilding
Wood with superpowers

Architect and biologist Timothée Boitouzet has used nanotechnology to give wood an upgrade. The new material “Woodoo” is translucent, fire-resistant, weatherproof and up to five times stronger than normal wood.

High-tech timber for Norwegian banking
#smart office
High-tech timber for Norwegian banking

Timber construction can be decidedly high-tech, as illustrated by the head office built for SR Bank in Stavanger, Norway. Bjergsted Financial Park offers workplaces that are fit for the future, and it is among Europe’s largest engineered timber buildings.

In harmony with nature
#greenbuilding
In harmony with nature

So, what does "Noom" actually mean? While Sanzpont [arquitectura] and Pedrajo + Pedrajo Arquitectos don't exactly reveal this, their "Living the Noom" concept is pretty clear: it’s all about a fresh take on housing. With environmental protection and quality of life as a top priority.

Hamburg sets a new benchmark
#greenbuilding
Hamburg sets a new benchmark

HafenCity Hamburg is an urban quarter fit for the future. Its eco cherry on the top is the “Null-Emissionshaus” (Zero Emissions Building), which is completely carbon-neutral – and can be dismantled like a Lego house.

The oblique cabins of Tungestølen
#hotel
The oblique cabins of Tungestølen

Snøhetta creates high-calibre architecture, including accommodation at high altitudes amidst Norway’s glaciers. The architects have enriched the Tungestølen mountain cabins with a special feeling of hygge.

Urban apartments off the peg
#greenbuilding
Urban apartments off the peg

Apple’s former design head BJ Siegel has developed a concept for a timber modular house. The urban prefab named Juno is designed for mass production – and hopes for success on the scale of the iPhone.

Village life in the city
#greenbuilding
Village life in the city

Communal vegetable patches, car sharing and a timber building that overtops many others. Sweden’s largest housing cooperative is celebrating its 100th anniversary with a project called Västerbroplan that shows how people will live in the future.

A superlative tree house
#greenbuilding
A superlative tree house

Bearing the name Tree House Rotterdam, Holland’s new landmark-to-be looks like a gigantic stack of wooden shelves with glass lofts added on top. It aims to take the sustainability of timber high-rises to a new level.

Co-housing 2.0
#living
Co-housing 2.0

Three tonnes of lettuce and vegetables annually will be farmed on top of the We-House, a timber construction project in Hamburg’s HafenCity. The on-site restaurant serves meals for residents of this sophisticated eco-house at cost price.

The parametric office
#smart office
The parametric office

The design for the urban office building Saint Denis in Paris shows the potential of parametric design in timber construction. Architect Arthur Mamou-Mani is a luminary in this new discipline, and we were able to meet him online.

Wood on London’s skyline
#greenbuilding
Wood on London’s skyline

Researchers at Cambridge University are helping to turn London’s spectacular vision of a wooden skyscraper into reality. The Oakwood Timber Tower is to rise 300 metres into the sky, almost level with the tallest building in the city.

Vertical allotments for urban farming
#city planning
Vertical allotments for urban farming

Self-sufficiency is no longer a dream reserved for downshifters. The modular building system named The Farmhouse designed by Studio Precht allows residents to grow food in big cities.

This site is registered on wpml.org as a development site. Switch to a production site key to remove this banner.