Thatched Building Facades for the Green Transition
The project aims to push the fundamental understanding of the potentials of biogenic materials in architecture with three main questions: How can architecture be created so it fully contributes to the green transition of society? How can architectural design increase the use of biogenic
materials in construction to help decreasing CO2 emissions? How can radical biogenic architecture be developed when integrating knowledge from traditional building culture/-craft with new building processes?
National
Denmark
CINARK - Center for Industrialised Architecture, The Royal Danish Academy https://royaldanishacademy.com/cinark/about-cinark
MUDP - The Danish Eco-Innovation Program https://ecoinnovation.dk/tilskud/naar-du-har-faaet-tilskud-fra-mudp/
The Danish Thatchers Guild https://www.danskindustri.dk/medlemsforeninger/Taekkelauget/om-taekkelauget/
It addresses urban-rural linkages
It refers to a physical transformation of the built environment (hard investment)
No
No
Yes
2022-12-31
As a representative of an organisation
Name of the organisation(s): CINARK - Center for Industrial Architecture, The Royal Danish Academy Type of organisation: University or another research institution First name of representative: Anne Last name of representative: Beim Gender: Female Nationality: Denmark Function: CINARK - Center for industrial Architecture Address (country of permanent residence for individuals or address of the organisation)<br/>Street and number: Philip de Langes Allé 10 Town: Copenhagen C K Postal code: 1435 Country: Denmark Direct Tel:+45 60 13 15 06 E-mail:CINARK@kglakademi.dk Website:https://kglakademi.dk/cinark-center-industriel-arkitektur
The project is based on a collaborative ambition across industry and academia to explore and enhance the idea of absolute sustainable architecture based on biogenic materials – under the heading ‘radical [architectural] tectonics’. It is funded by the Danish Environmental, Technology, Development, and Demonstration Program (MUDP) together with the involved partners. It is organized as a practice-oriented research collaboration between craftsmen, fire engineers and architectural researchers represented: by two master thatchers, one clay-mason, The Danish Institute of Fire & Security Technology (DBI), The Office of Thatching (Secretariat for ITS - International Thatching Society), and Center for Industrialized Architecture – CINARK, the Royal Danish Academy.
Fire-safety is central when aiming at developing absolutely sustainable architectural solutions with biogenic materials. This project sets out to investigate, how material choices and radical tectonic solutions can act as drivers for a sustainable change in the construction industry, building legislation and architectural practice focusing on fire-preventing construction design. The aim is to provide credible CO2 neutral construction typologies with environmentally low impact, ‘close-to-standard’ fire-retardant properties – and that can be scaled to an industrial level. In this context reed is a very interesting material, as it has a fast growth period, it can absorb a range of critical greenhouse gasses, and it sustains biodiversity.
The project has three main components:
1. Researching into clay’s use in thatched constructions in Denmark and Northern Europe in both historical building culture and present constructions.
2. Development, design, and production of thatched structures plus technical quality assessment and dissemination of prototypes to a broader international public
3. Comparative fire-tests of thatched façades with clay-based fire retardants assessed on different parameters.
Biogenic Construction
Fire-protection
Decrease CO2-Emission
Sustainability
Industrialized architecture
To meet the Danish political ambition of reducing CO2 emissions by 70% by 2030 all forms of CO2-saving measures must be considered. With point of departure in biogenic materials such as reed and straw, the project investigates, how material choices and radical tectonic solutions can act as drivers for a sustainable change / transformation in the construction industry.
The thatched house corner is developed as a full scale prototype that showcase aspects related to fire-protection of biogenic materials by use of clay as a fire-retarder (impregnating the surface). Although, the project also answers to additional important aspects in construction such as: use of non-toxic materials, breathable/diffusable structures, CO2 reduction, biodiversity and circular economy.
A growth in thatched roofs and facades is estimated to have a great effect. In regard of sustainability reed is a very interesting material, as it has a fast (annual) growth period, it can absorb a range of critical greenhouse gasses, and the material 'production' sustains biodiversity. There are many environmental benefits when increasing the use/square meters of thatched constructions. This is because reeds and miscanthus (for thatching), like all living organisms, absorb and capture CO2 from the atmosphere while growing. Therefore, “reed forests” are often referred to as the “lungs of the earth”. At the same time, the cultivation of reed forests has a positive effect on the aquatic environment. Reeds absorb nutrients such as nitrate and phosphate from wetlands, which counteracts oxygen depletion and the growth of algae.
The project’s long-term objective is to provide new knowledge to support an increase in thatched vertical surfaces in Denmark/EU. Also, CO2 emmissions related to the production of synthetic fireproofing membranes and chemical flame retardants, as well as their disposal, can be avoided if the fire protection also becomes biodegradable eg. by use of natural clay.
The Danish Wadden Sea Center by Dorte Mandrup Architects made headlines in 2017, also outside the circles of architects and the construction industry. The museum was placed in the sensitive landscape of the Wadden Sea in southern Denmark appearing as a homogeneous material figure with openings for windows and doors looking as if they were cut out of a large body of compressed reed. The design lifted the idea of thatched roofs out of a farmhouse romanticism into contemporary architecture and showed novel ways of using reed and thatch.
The Biogenic Construction project has point of departure in similar contextual material understandings. The prototype as built - is an intuitively, readable and touchable structure. The tactile materials invite the viewers to engage in the greater context of material culture, their production, tectonic principles, and architectural detailing. The design features are generated on the basis on historical building culture, technical demands, and reinterpretation of craft traditions.
Although the project addresses technical issues due to the fire testing set-up, it has received broad international interest for its architectural design. The project and prototype structure has been nominated, selected, and displayed ed at one curated exhibition at the Royal Danish Academy, and two Triennale exhibitions - peer reviewed by international committees:
- Construction (prefab) was displayed at the Trienal de Lisboa 2022, TERRA, Portugal. Here it also winner of the international prize: 'Research Category Award'. https://www.trienaldelisboa.com/programme/triennali/2022_en
- Construction (in-situ) has been displayed at the 'Triennial Architecture of Necessity' 2022: https://www.virserumskonsthall.com/architecture-of-necessity/
- Winner of the 'Courage Prize 2022’ awarded by the Danish Art's Foundation.
- Selected for the 'AR Future Projects Award 2023 / Research & Design Category' (NB! not yet publicly announced)
The project is meant to show new architectural and spatial possibilities by use of biogenic materials and sustainable design. The materials reed and clay are considered cheap and easily accessable in most countries, besides the material production of reed and the escavation of clay are not energy intensive.
We hope that the project will bring light to the benefits of using biogenic materials that are environmentally safe, that enhance the quality of local craft traditions in building, and the educational potentials for the next generations. The design features included in the project are mainly generated from a material perspective and according to the fire-testing standards to be able to test the fire-performing/-retarding properties of the materials and the construction design.
However the construction principles generated for the biogenic constructions are considered to be applied for diverse building structures that can built accordingly to present building regulations that include standards for accesibilty and univarsal design.
The project results and possible architectural application do not lead to architecture that hinders inclusion or accessibility or affordability.
The target group of the project and the use of the new biogenic construction solutions with natural clay fire-protection is primarily clients, architects and manufacturers of biogenic building materials/components who want to build with a 70% CO2 reductions in mind. In addition, fire consultants and thatchers will be important players when the building techniques and construction solutions are to be implemented.
The project har been widely disseminated in both lectures, podcasts, interviews, professional journals, scientific articles, public exibitions to the general public (in both Denmark, Sweden, Portugal and Germany).
Also the project is reported in a publically accesible digital version (report) that is published on the homepage of the Danish Enviromantal Agency (Ministry of Environment). "Tækkede bygningsfacader til den grønne omstilling - CO2-neutral brandsikring af tækkede lodrette flader", January 2023.
As mentioned it has gained great international attention and has been exhibited internationally.
The project is funded by the Danish Environmental, Technology, Development, and Demonstration Program (MUDP) together with the involved partners.
The researchers of CINARK, Center for Industrial Architecture have developed the research design and managed the project. CINARK researches and develops new sustainable products and processes for industrialized construction in close cooperation with companies and construction organizations.
The fire engineers at DBI have ensured the quality in the test designs and analyses of results which form the basis for further development of products regarding scaling to industrial level.
The craftsmen have the two thatchers and the clay mason have been responsible for the development/construction of thatched constructions. Thomas Gerner/Thatcher is also chairman of the Thatchers Guild and has sat on the guild's Technical Committee. Thomas has a lot of experience with professional dissemination through articles and professional events, e.g. for the Straatagets Kontor and has a particular focus on the thatching companies as a potential driver of a green agenda. Together with Ruud Cojin/Thatcher and Lasse Kofoed Nielsen/Clay Mason, Thomas has playyed a central part in the development of the newly conceived vertically thatched construction solutions with clay as a CO2 neutral fire retardant.
The project's progress has been followed by an advisory board consisting of Mikael Kock/Wood Information, Lars Keller/EcoCocon Denmark, Susanne Pouline Svendsen/BygErfa (A collects and processes technical experiences from the construction and building industry) and Ida Sofie Martinsen from the Danish Environmental Protection Agency, in addition to the project's partners. They have critically commented the process and results of the project at an annual meeting.
The project is organized as a practice-oriented research collaboration between craftsmen, fire engineers and architectural researchers represented: by two master thatchers, one clay-mason, The Danish Institute of Fire & Security Technology (DBI), The Office of Thatching (Straatagets Kontor/Secretariat for ITS - International Thatching Society), and Center for Industrialized Architecture – CINARK at the Royal Danish Academy - School of Architecture. The project has definately benefitted from the different perspectives between architectural design, craft knowledge, and scientific tests and analyses.
In close cooperation with the thatching companies and the clay mason, it is ensured that the new vertical thatched solutions with clay as fire protection are developed to fit into the companies' established workflows and production methods, in order to be included in their advisory services and deliveries. Thatched roofs are financially sound, as effective fire protection reduces the insurance costs. As the project may offer fire-proof solutions, insurance reductions could also apply to vertically thatched facades. It is a high priority that the new construction solutions are easy to use, can be scaled, and used in construction directly. That is why collaboration across the disciplines, a high degree of knowledge sharing, and debate during and after the project has been important, so everyone; the needs of both the thatching companies, biogenic material manufacturers, fire-engineers, clients, and architects are met - but equally so that the regulatory authorities can see the possibilities for improvements.
The results of the project can also inspire Danish building manufacturers to develop bio-based building products with natural clay fire-protection and can equally be used by the Danish fire consultancies.
Thatched roofs are imbedded in Danish building traditions. Thus, more use of thatched surfaces may enrich the understanding of the cultural heritage in construction and bring thatching to forefront of contemporary architecture. The projects show how imbedded knowledge in local craft traditions and testing of new tectonic solutions for fire-protection can push conventions in the construction industry and lay the grounds for new sustainable building cultures.
The project has been successful in developing and testing construction solutions unprecedented (in DK)
Results from the R&D, and the fire-tests can be summarized as follows:
• Historical research shows that clay has been used as a fire-retardant in thatched roofs in Denmark.
• Impregnating reed with clay-based materials provides a significant fire-retarding effect of vertically thatched surfaces.
• That clay proves effective to reduce fire-spreading in vertically thatched facade constructions and on the surface.
• Increased fire-retarding effect is gained by incorporating clay panes as a horizontal material change (fire stop) in the facade cladding of reed.
• International fire-testing standards are meant for conventional industrial products and not in-situ constructions depending on craft-based techniques as thatched cladding with clay impregnation. Standardized testing regimes can be an obstacle to developing green solutions based on these crafts and building techniques.
• Full-scale facade constructions in biogenic materials with EcoCocon straw elements as load-bearing wall and thatched facades impregnated with clay, demonstrate a new construction typology. It proves to meet the present requirements for a 70% reduction of buildings' CO2-emissions (DK) and it has gained broad international interest across Universities and professional communities.
Thatched roofs are imbedded in Danish building traditions. Thus, more use of thatched surfaces may enrich the understanding of the cultural heritage in construction and bring thatching to forefront of contemporary architecture. The projects show how imbedded knowledge in local craft traditions and testing of new tectonic solutions for fire-protection can push conventions in the construction industry and ideally lay the grounds for new sustainable building cultures.
Presently there is no serious competition or market-driven innovation in the Danish construction industry that is oriented towards the 'biogenic material market'. Thus, the project can have an ice-breaking effect, as the solutions are thought of across materials (reed and clay) and small innovative construction companies where new product ideas and collaborations can arise. The fully developed construction solutions with bio-based fire protection will add both environmental added value to the construction sector, as well as create an ‘biogenic narrative’ that can be used to create publicity and focus on construction's environmental improvement potential in DK and internationally.
Most new knowledge and product development amongst thatching companies come from the Netherlands. Thus, the project has investigated Dutch research results, products and techniques. In the Netherlands there has been a 50% increase in thatched building facades in the last 10 years. The Netherlands is then a leading country in the development of new, standardized thatching solutions for both roofs and facades. The project does not aim to compete with established methods, but to improve the construction techniques with a 100% biodegradable (clay) fire protection. Industrialized construction solutions with biodegradable fire protection for biogenic materials as reed have not yet been developed in Denmark or internationally so the project is the first of its kind.
This project sets out to investigate, how material choices and radical tectonic solutions can act as drivers for a sustainable change in the construction industry, building legislation and architectural practice focusing on surface treatments and construction design with biogenic materials as reed.
Fire-safety is central when aiming to develop sustainable architectural solutions with biogenic building materials. Thus, it was important to clarify how the newly created constructions in the project were to be tested and what sort of standards made sense to apply. Also, it had to be clarified whether it was fire protection of the surface or the entire structure and/or the spread of the flames that were to be investigated. Thus, the test methods were specified in parallel with the new types of constructions that were to be tested.
The fire-tests have been based on a function-based approach, since “pre-accepted solutions” defined in the Danish building regulations were not suitable. Thus, it was decided to only focus on the 'weather shield' of the construction (the covering layer and the clay impregnation).
This part of the project consists of two stages of fire-testing:
1. The first stage was a scaled-down version of a SBI (Single Burning Item test (EN13823)). The mini-SBI must determine which impregnation method was found to have the best fire technical properties. A total of 14 types were tested. The type: Fully impregnated with moraine clay was selected for the subsequent scaled-up fire tests.
2. The second stage was three full-scale tests in 1200 mm x 2400 mm (a customized version of ISO 13785-1:2002 (E)), one unimpregnated, one fully impregnated with a smooth surface, and one fully impregnated with a profiled surface with horizontal clay plates acting as a fire-stop.
Subsequently, thatched clay impregnated surfaces have been tested as full-scale prototype structures.
The project has led to the Biogenic Construction (in-situ) and the Biogenic Construction (Prefab) are both a part of the testing with clay as a fire retardant for thatched facades.
The in-situ Biogenic Construction is designed and built accordingly to existing craft traditions and building techniques by use of thatching. Thatching is a global craftmanship which it going back to early settlements of civilization and therefore the materials and the building techniques reach many different building cultures.
We believe that the results and knowledge gained by 'stretching' the use of traditional craft knowledge in combination with other disciplines can be easily be replicated and transferred to other countries with similar craft traditions.
The Prefab Biogenic Consteruction is testing thatched prefabricated facade elements based on the knowledge gained from the in-situ Biogenic Construction.
In this construction the intention is to uncover the technological challenges when developing a market-ready construction solution with a 100% biodegradable fire protection that can be scaled to an industrial level. In order to scale the construction solutions, i.a. technical standards are defined and followed so that the novel construction solutions can be used in the current construction industry, as well as robust supply chains easily can be established. It is then important that the biogenic materials used maintain a high, uniform quality and that they are produced locally to reduce the need for transport.
The biggest challenges on the way to the market in both Denmark and internationally, will be developing standardized construction solutions that meet building legislation and fire requirements in the various EU countries.
The building sector has a large CO2 and environmental responsibility, as it accounts for 40% of total CO2 emissions, and is a sector that has a high consumption of natural resources. Several countries have introduced requirements for energy efficiency in new construction and renovation, which has led to an enormously energy-intensive building practice, both in relation to the production of building materials and the construction of the building. In some cases, more energy is used to construct the new energy-efficient buildings than what can be achieved from energy savings in the operation of the buildings. Therefore, it is important that a sustainable development of construction is not only about operationally efficient buildings, but also the development of new construction technical solutions and materials that have a low CO2 footprint throughout the value chain – from the production of materials, to behavior, operation and disposal.
The projects show how imbedded knowledge in local craft traditions and testing of new tectonic solutions for fire-protection can push conventions in the construction industry and lay the grounds for new sustainable building cultures. The global change lies in a new fundamental understanding of seeing local craft and traditional construction in a new industrial perspective.
A combination of clay and reed is very interesting from a sustainable point of view, as both materials are 'produced' locally without energy intensive processing, and they are also 100% biobased. This results in building constructions with a very small CO2 footprint, as neither large resources are used for production nor transport, which is a prerequisite for leading construction closer to the CO2 reductions needed at a global level.
