Industrialized Low-Impact Construction: Madreselva Building
Comparative Analysis. 3 Cases in 3 Dimensions: Water, Waste, and Carbon
In an increasingly sustainability-conscious world, the construction of ecologically responsible buildings has become a priority, and the Madreselva building is a prominent example of this trend. As a fundamental part of our methodology, technical wood represents for Woodea a decisive step towards decarbonizing construction and our effective contribution to sustainability.
In this article, we will explore the results of a life cycle assessment (LCA) comparing three construction models identified as Madreselva, Woodea, and Traditional. The aim of this analysis is to evaluate the carbon footprint, water usage, and waste generation over the 50-year lifespan of this building.
Low-impact industrialized construction through the Madreselva building
The Madreselva building is a new residential construction project that stands out for its focus on sustainability. Located in Burjassot, Valencia, it is under construction during 2023/2024 and aims to achieve a valuable 4-leaf rating in the Green certificate granted by Green Building Council Spain (GBCE).
This project, designed by the architecture studio FVAI and promoted by Zubi Cities, differs from traditional construction through a combination of three materials: concrete for foundations and basement, and wood and metal structure. Functionally and design-wise, it also stands out thanks to its multiple common areas and interior garden spaces, as can be seen in the following video.
The central purpose of this analysis is to compare three structural construction systems (Madreselva, Woodea, and Traditional) based on three scenarios subjected to a Life Cycle Assessment (LCA) evaluating their carbon footprint, water consumption, and waste generation.
To ensure a fair comparison, the selected functional unit is the construction and use of a Build to Rent residential building with 14 units in Burjassot (Valencia) on 5 floors with a 4-leaf Green certification for 50 years. All three scenarios have the same fire protection, insulation, and energy consumption. The built area is 1,532 m2, excluding parking.
The LCA covers all stages, from raw materials to the end of the building’s life, including the transport and treatment of generated waste. This ensures a comprehensive assessment of the environmental impacts involved in each scenario.
The study focuses on three key categories of environmental impact:
- Climate Change: Construction and building use account for 40% of global CO2 emissions. This analysis evaluates the carbon footprint of the building’s entire life cycle, including carbon absorption from wood. Results are expressed in tons of CO2 equivalent (t CO2-eq).
- Water Usage: Only the construction sector consumes 16% of the world’s water resources. This indicator in the report addresses water consumption, including evaporation, transpiration, and other factors. Water usage units are measured in cubic meters (m3).
- Waste Generated: The volume of debris and waste generated by construction is equivalent to one out of every three of those buildings. The report considers all materials leaving the analyzed system, including construction waste and building materials at the end of its lifespan. Results are expressed in tons (t).
Comparative analysis of three construction scenarios
The three construction scenarios under analysis share common functional features such as energy consumption and spatial arrangement. Their functional characteristics are, therefore, the same, with the only variations occurring in the materials of the structure, foundation sizing, and concrete bricks in the facade.
Evaluation of results
Carbon footprint in production and construction phase
The Madreselva building and the Woodea model strongly demonstrate their commitment to sustainability by significantly reducing the carbon footprint in the production and construction phases compared to the Traditional model. The current climate crisis has increased the relevance of this stage, as adopting this construction system could imply a significant reduction in emissions.
Madreselva reduces the carbon footprint by an astonishing 58% in these phases, while the Woodea scenario surpasses it with an even greater reduction of 80%. These figures are 43% and 59%, respectively, over the entire life cycle.
These figures are remarkable and clearly demonstrate the positive impact of using wood as a construction material instead of other traditional materials.
Waste generated on site (t)
Both Madreselva and Woodea demonstrate their efficiency by requiring fewer materials in construction (~2,700 t vs. ~4,000 t), thereby generating less on-site waste. Additionally, wood and steel used in these models are highly recyclable, promoting a circular economy.
Woodea reduces generated waste by 31%, and Madreselva does so by 10% compared to the Traditional model.
These results underline the contribution of building with wood to waste reduction and responsible resource use.
Water consumption for each scenario and by phase (m3)
In water consumption reduction, both Madreselva and Woodea outperform the Traditional scenario, highlighting again the efficiency caused by the selection of construction materials.
Woodea and Madreselva would reduce water consumption in this phase by 36% and 34%, respectively, compared to the Traditional model, with the reason being the impact of increased concrete usage.
The choice of more sustainable materials and construction methods translates into more efficient water use, a valuable resource.
Evaluation of Impacts
Impact on costs of industrialized construction with wood
Although there may be an initial 10% cost overrun in direct costs by opting for wood structures, this over cost significantly reduces due to reductions in construction timelines and other factors.
The final over cost ranges between 3% and 4%, including reductions in indirect costs and margins for builders and developers.
These data suggest that, despite starting with a slight cost increase, choosing wood as a structural material can result in a profitable long-term investment.
Impact of wood structure on housing prices
Since construction costs represent approximately half of the final selling price of a home, the additional cost of a wood structure results in an increase in the selling price, ranging between 1.5% and 2%.
This translates to an increase of between 3,000 and 4,000 euros in a home with a price of 200,000 euros.
While there is a slight price increase, it can be considered a reasonable investment in terms of sustainability and long-term benefits.
Advantages of building with wood for the developer and society
Choosing wood construction not only has environmental advantages but also aligns with current trends in the real estate market.
Promoting buildings with wood structure can be attractive to climate-conscious and sustainability-aware investors. Additionally, developers adopting more sustainable approaches can stand out in a competitive market and attract a clientele that values a more ecological and communal lifestyle.
Conclusions of the analysis
The life cycle analysis conducted on the Madreselva building provides valuable data on the environmental impacts of different construction models. As society seeks to build more sustainably, it is evident that the choice of materials and construction methods plays a critical role in reducing the environmental footprint.
The Madreselva scenario stands out for its balanced approach in wood and steel, contributing to a lower carbon footprint compared to the Traditional scenario.
On the other hand, the Woodea scenario, primarily built in wood, shows significant potential to reduce environmental impact, especially in terms of water usage and waste generation.
In summary, this analysis demonstrates that sustainable construction is possible, and the choice of materials and construction methods can make a significant difference in reducing environmental impacts.
The Madreselva building, with its focus on wood and sustainability, represents a significant step towards a more ecological future in residential construction.