Marine Biobased Materials: Comparative Study of Hygroscopic Behaviour and Environmental Impact in Interior Applications
(2025) AEBM01 20251Division of Energy and Building Design
- Abstract
- Growing environmental concerns have brought a focus to the impact of building materials. In response, biobased alternatives are being explored for their potential to reduce embodied carbon, support circularity, as well as improve indoor environmental quality. This is particularly important in Scandinavia, where moisture-related issues are common, there is a growing need for locally available materials that can both regulate humidity and reduce environmental harm. Marine biobased materials, such as seagrass and seaweed, present promising yet under-researched options. These resources are especially relevant in the Scandinavian region, where abundant coastlines
make marine biomass both accessible and well-suited to local building... (More) - Growing environmental concerns have brought a focus to the impact of building materials. In response, biobased alternatives are being explored for their potential to reduce embodied carbon, support circularity, as well as improve indoor environmental quality. This is particularly important in Scandinavia, where moisture-related issues are common, there is a growing need for locally available materials that can both regulate humidity and reduce environmental harm. Marine biobased materials, such as seagrass and seaweed, present promising yet under-researched options. These resources are especially relevant in the Scandinavian region, where abundant coastlines
make marine biomass both accessible and well-suited to local building traditions. This thesis investigates the moisture-regulating and environmental properties of eelgrass panels and seaweed-based biochar lime, comparing them as alternatives to conventional materials: gypsum boards and standard lime. Hygroscopic performance was assessed through the material sorption isotherms, derived from the glass jar experiment, and additionally an indoor humidity simulation using WUFI. Environmental impact was evaluated through a comparison of environmental product declarations (EPDs) and literature on material production and circularity. Results show that the biobased materials outperform their conventional counterparts in both moisture buffering capacity and environmental impact. Eelgrass panels, in particular, demonstrated a notable
reduction in indoor relative humidity fluctuations by at least 5 % compared to gypsum, while seaweed-based biochar lime exhibited improved buffering performance over conventional lime. These findings underscore the potential of marine biobased materials in addressing both environmental and indoor climate challenges in construction, warranting further investigation and practical application. (Less) - Popular Abstract
- Much of the building stock in Scandinavia struggles with poor indoor air quality and inadequate ventilation, which leads to polluted homes and strong humidity fluctuations. Humans, ideally, prefer a steady moisture level, not too humid, since this leads to condensation and even mould growth, and not too dry, since it can be bad for our skin and our breathing. But can the materials we build with help regulate this indoor moisture naturally?
Through the exploration of different biomass available in Scandinavia, I’ve found two materials that might outperform current conventional materials. The first material is seagrass panels; a novel biobased alternative made from harvested seagrass. The second material is seaweed-based biochar and lime.... (More) - Much of the building stock in Scandinavia struggles with poor indoor air quality and inadequate ventilation, which leads to polluted homes and strong humidity fluctuations. Humans, ideally, prefer a steady moisture level, not too humid, since this leads to condensation and even mould growth, and not too dry, since it can be bad for our skin and our breathing. But can the materials we build with help regulate this indoor moisture naturally?
Through the exploration of different biomass available in Scandinavia, I’ve found two materials that might outperform current conventional materials. The first material is seagrass panels; a novel biobased alternative made from harvested seagrass. The second material is seaweed-based biochar and lime. I’ve chosen these materials since they’re local to the Scandinavian region. After testing their absorbance properties, I’ve found that both of the biobased materials in my study outperform conventional alternatives. Using the WUFI simulation software, I was able to show how these materials are able to regulate the indoor moisture fluctuations. Not only will this result in healthier indoors, but it could also reduce mould growth in indoor spaces, especially poorly ventilated ones!
The other aspect where these biobased materials outperform is in their sustainability. These materials are made from natural waste, and do not rely on mining or fossil-based resources. Moreover, they can be recycled, making them truly circular.
Nevertheless, more research is needed to get the full picture of these materials; for example, it is well known that organic matter is more susceptible to mould growth. Therefore, it is important to explore if this presents a real risk and if there are ways to mitigate it. Still, this study shows how marine-based materials could play a big role in creating healthier and more sustainable homes. (Less)
Please use this url to cite or link to this publication:
http://lup.lub.lu.se/student-papers/record/9195823
- author
- Vujnovic, Sara LU
- supervisor
- organization
- course
- AEBM01 20251
- year
- 2025
- type
- H2 - Master's Degree (Two Years)
- subject
- keywords
- Bio-based Materials, Indoor Climate, Indoor Moisture, Eelgrass, Seagrass, Seaweed, Biochar, Lime, Mold, Circularity
- language
- English
- id
- 9195823
- date added to LUP
- 2025-06-10 10:38:07
- date last changed
- 2025-06-10 10:38:07
@misc{9195823,
abstract = {{Growing environmental concerns have brought a focus to the impact of building materials. In response, biobased alternatives are being explored for their potential to reduce embodied carbon, support circularity, as well as improve indoor environmental quality. This is particularly important in Scandinavia, where moisture-related issues are common, there is a growing need for locally available materials that can both regulate humidity and reduce environmental harm. Marine biobased materials, such as seagrass and seaweed, present promising yet under-researched options. These resources are especially relevant in the Scandinavian region, where abundant coastlines
make marine biomass both accessible and well-suited to local building traditions. This thesis investigates the moisture-regulating and environmental properties of eelgrass panels and seaweed-based biochar lime, comparing them as alternatives to conventional materials: gypsum boards and standard lime. Hygroscopic performance was assessed through the material sorption isotherms, derived from the glass jar experiment, and additionally an indoor humidity simulation using WUFI. Environmental impact was evaluated through a comparison of environmental product declarations (EPDs) and literature on material production and circularity. Results show that the biobased materials outperform their conventional counterparts in both moisture buffering capacity and environmental impact. Eelgrass panels, in particular, demonstrated a notable
reduction in indoor relative humidity fluctuations by at least 5 % compared to gypsum, while seaweed-based biochar lime exhibited improved buffering performance over conventional lime. These findings underscore the potential of marine biobased materials in addressing both environmental and indoor climate challenges in construction, warranting further investigation and practical application.}},
author = {{Vujnovic, Sara}},
language = {{eng}},
note = {{Student Paper}},
title = {{Marine Biobased Materials: Comparative Study of Hygroscopic Behaviour and Environmental Impact in Interior Applications}},
year = {{2025}},
}