Magazine
MAGAZIN
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.

Forming an expansive arch, a latticed roof stretches along the length of the 80-metre production hall. The space underneath is able to flow freely from one end to the other, interrupted by neither columns nor pillars. This lamella construction made of wood creates aesthetics that are unexpected in a factory workshop, with its focus on functionality. Built by timber engineering company Reichart Holzbautechnik, although the hall is a construction that reduces the use of materials, it is also a striking example of their timber construction expertise.

Villa Parolo, Bad Saarow, Zollinger roof
Villa Parolo in Bad Saarow is a listed building that was erected in the early 1920s with a Zollinger-type roof.

Innovation combats housing shortages

The vaulted hall in the Bavarian spa town Oberstaufen draws inspiration from the Zollinger roof that was originally developed by Merseburg’s master builder Friedrich Zollinger. He was granted the patent for this construction system just over 100 years ago, in 1923. As is the case with many innovations, it was also developed out of necessity. In the 1920s, Germany was focusing on building new living space as cheaply and rapidly as possible.

A structure like this indicates to customers that we are not just any manufacturer, but instead passionate about developing timber constructions.


Helmut Reichart, master carpenter in Oberstaufen

The construction method devised by Zollinger is based on a grid of timber elements as a structural framework. These are prefabricated individual pieces that are put together in a diamond-shaped design. This construction had numerous benefits compared to roof trusses with a conventional method: the amount of wood could be reduced by 40 percent, while allowing a better use of space. In addition, modular building proved so simple that building contractors and amateurs were able to help with assembly, which additionally lowered the costs of construction.

Processing hall, Reichart Holzbautechnik, Zollinger roof, Oberstaufen
At a length of 80 metres, the construction method chosen for the processing hall at Reichart Holzbautechnik is based on the Zollinger roof.

Fit for the future

100 years on, the construction sector is again on the search for clever ideas and innovations. Man-made climate change is currently presenting the greatest challenge ever experienced by the industry. There is a demand for resource-friendly and biobased construction solutions that turn the built environment – in addition to forests and moors – into a carbon sink. When wood or straw, for example, are used as building materials, the carbon that is stored inside remains locked up over the long term, while newly planted trees and crops can absorb more CO₂ from the air.

As the vaulted lamella structure based on Zollinger’s design combines these ecological requirements, it can be considered progressive – even though it is over one hundred years old. And these days, calculations for structural design are much more precise. While for many decades the forces at work here could only be proven as an approximation, today’s digital planning tools are able to solve imprecisions.

A research group from Leipzig University of Applied Sciences (HTWK) modernized this construction method, and in 2016 they were presented with an award for their outstanding services to monument preservation in Europe.

Close-up, Reichart Holzbautechnik, Zollinger roof, Oberstaufen
Instead of the original bolts – which were prone to deformation – Reichart chose a dowel-type connection and fully threaded screws.
Processing machine, Reichart Holzbautechnik, Zollinger roof, Oberstaufen
The Zollinger roof is well-suited to self-assembly, and the individual construction elements were mass produced using this machine.

More space, less material, huge effect

As a result, media interest in Zollinger’s design has increased in recent years, which is how carpenter Helmut Reichart became aware of it. When he purchased an 8,000 square-metre plot of industrial land in 2021 for his company and its 23 workers, he was convinced that he wanted a production hall with a vaulted Zollinger roof.

“I was especially fascinated by the elegance of the construction – it makes a hall like that look extremely good,” the carpenter explained in conversation with timber construction magazine mikado. “A structure like this indicates to customers that we are not just any manufacturer, but instead passionate about developing timber constructions.”

This self-supporting timber structure with its arched shape enables an ideal use of space. A flat load distribution allows large spans without any need for supports. Wood is regionally sourced, and the resource-friendly design saved a lot of material. All planning, production and assembly could be handled on-site by the carpenters themselves.

Building site, Reichart Holzbautechnik, Zollinger roof, Oberstaufen
The amount of wood needed was reduced by up to 40 percent owing to Zollinger’s resource-friendly design.

Angular goes curved

However surprising this might sound to most people, not a single curved beam was used in the construction of their vaulted roof. The individual elements are all straight, with the curved shape only being achieved by slanting joints where the pieces of timber meet. The relatively short pieces of wood are fitted together serially, forming a three-dimensional grid with three lamellae at each point of junction.

Basically, the construction consists of just two recurring elements that can be produced on a large scale using CNC wood-cutting machines. “When you consider that there are about 2,000 individual elements, the issue of cost is hugely important,” explains Reichart. In addition, the design only uses shorter pieces of wood, which are themselves cheaper.

Assembly, Reichart Holzbautechnik, Zollinger roof, Oberstaufen
Slanting joints at each connection achieves a rounded shape, although the individual elements are all straight.

And the familiar vulnerability of the original construction – the bolted connection that was likely to suffer from deformation over time – was eliminated by the carpenter, replacing it with a dowel-type connection.

Aside from the benefits of timber in the path to net zero, the Zollinger roof offers a combination of so many advantages, it is bound to be used more often in future.

Text: Gertraud Gerst
Translation: Rosemary Bridger-Lippe
Photos: Reichart Holzbautechnik

Other articles
that might interest you

University enters the green building revolution
#greenbuilding
University enters the green building revolution

The Marga Klompé Building at Tilburg University is the first academic building in the Netherlands to be built out of wood. Insulation made from recycled denim jeans is part of the circular design by Powerhouse Company.

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.

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.

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.

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.