SUSTAINABLE & CIRCULAR
Hot-dip galvanizing scores highest of all steel preservation methods in terms of sustainability. Building materials made of steel already have a good environmental balance, and protection against corrosion by zinc adds a lot to that. Depending on the thickness and quality of the atmosphere, a zinc coating lasts for many decades. After use, iron and steel are collected and recycled. Due to its long life and high recycling rate, hot-dip galvanized steel has an excellent environmental profile compared to painted or otherwise protected steel.
In the Netherlands, Rijkswaterstaat released a Handreiking Duurzaam Staalconserveren 2.0 in 2025
The Ministry of Infrastructure and Water Management’s ambition is to be fully climate neutral and circular no later than 2030. Rijkswaterstaat has embraced these ambitions. The Strategy Towards Climate Neutral and Circular National Infrastructure Projects (CIP) should help achieve the stated ambitions.
Rijkswaterstraat uses the Environmental Cost Indicator (MKI) for this purpose. MKI is calculated on the basis of a life cycle analysis (LCA). LCA is a calculation method that calculates the environmental impact of the entire life cycle of a product; for nineteen different environmental impact categories. Among others, climate change (in kg CO2-eq), ozone depletion, acidification, and toxicological effects are part of the calculation. The environmental impact of the various categories is weighted and expressed as a 1-point score, the environmental cost indicator, expressed in euros. Using the EQI, different conservation techniques can be compared, taking into account the appropriate maintenance regime.
In the guideline, RWS has drawn up a schedule of choices to arrive at a preservation requirement for future new construction projects. The scheme gives the most sustainable choice for preservation which depends on the lifetime of the object.
This chart shows that hot-dip galvanizing is at the top of the order of preference for steel preservation. This order of preference was arrived at on the basis of a multi-criteria analysis for the various preservation techniques. Hot-dip galvanizing gives the lowest environmental impact for all possible residual lifetimes of a structure.
The chart below shows the MKI comparison of different preservation systems suitable for atmospherically loaded steel structures. Paint systems are the starting point, these have a value of 100%. At a higher percentage the system is less durable, at a lower percentage it is more durable than a paint system. The MKI depends on the lifetime of the structure. On the left in the graph is the MKI of a structure with a 25-year service life, in the middle for a structure with a 40-year service life, and on the right for a 100-year service life. At each of the three, hot-dip galvanizing scores noticeably better than alternative preservation systems.
Clients often underestimate the impact of regular maintenance on the total life-cycle cost of a steel structure. With hot-dip galvanizing, unlike paint systems, you are free of maintenance worries for decades. The example below of the Eiffel Tower illustrates this perfectly.
