The Environmental and Cost Benefits of Structural Wood

Engineered wood product Laminated Veneer Lumber (LVL) can reduce the impact on global warming when used in place of steel and will also save on overall project costs, research shows.

A recent study conducted by Rotorua Crown Research Institute Scion for Carter Holt Harvey Woodproducts compared the design of an 1800m2 warehouse made using LVL wood products with one constructed of steel. The research confirms that LVL reduces the impact on global warming by up to 56% as compared to steel.

LVL products have the strength characteristics required to replace steel in long-span systems such as warehouses, school gymnasiums and community halls.

The study, based on the accepted ISO Life Cycle Assessment methodology compares identical 1800m2 warehouses - one with an LVL Portal Frame, the other steel, both designed to bear the same loads. The research includes a full life cycle scenario (based on production data provided by CHH Woodproducts) including assumptions of landfilling for the LVL materials, and steel recycling.

The results come on the back of previous New Zealand and international Life Cycle Assessment studies that demonstrate wood’s environmental attributes in different building situations.

The cost saving from using LVL products in place of steel in this type of building is significant - up to 9% in total costs can be saved when the completed structures are compared - and likely to grow as the cost of energy-intensive steel rises over time.

Global Warming Potential of LVL vs Steel (Scion research)

• By replacing a steel Portal Frame System with an LVL Portal Frame System containing the products hySPAN, hyJOIST, and hyCHORD in an 1800m2 warehouse, 20,763 kg CO2 equivalents are saved in emissions over the life cycle of the building (including the end of life phase).
• At the end of the production phase the LVL products store 65,457 kg CO2 equivalents (retained in the wood) while the comparable steel materials have emitted 66,274 in CO2 equivalents into the atmosphere, giving a combined difference of over 130 tonnes.
• The Scion research is a simplified LCA study which follows the principles of ISO 14040.  The methodology used has not been peer reviewed - one requirement of ISO14040. The results are based on a number of assumptions.
• The research organisation that undertook the study used a neutral, scientific approach without endorsement of any product.

Life Cycle Assessment

• Life Cycle Assessment (LCA) is an analytical tool for the evaluation of the environmental impacts of a product, process or service system through all stages of its life. It extends from extraction and processing of raw materials through to manufacture, delivery, and use, and finally on to waste management. This is often referred to as “cradle to grave”.
• LCA can be used for product improvement and design by identifying environmental hotspots in production processes, or upstream or downstream processes, such as the type of energy used in the production process, additives used in the product or in the use phase of a product.
• LCA results can also be used as part of an environmental management system for continuous improvement or for providing information for eco-labelling or environmental rating schemes.