Will Wood be the Future of Skyscraper Engineering?
Kagan Pittman posted on June 04, 2015 |

Imagine the Empire State Building. Now image it made of wood. That concept may sound ludicrous at first, but Metsä Wood, a Finnish woods products producer is tackling the idea to prove its feasibility, titling the project ‘Plan B.’

For nearly 40 years after its completion in 1931, the Empire State Building was the tallest building in the world, standing at 1,454 ft. with 86 stories. Designs for a wooden version of the building mirror exactly the overall size, floor to floor height and column spacing.

The overall building size, floor to floor height and column spacing are the same as the original structure. The columns extend as much as six stories high, with moment connections at these locations to make each column structurally continuous up to 86 stories. Box beams connect the column along the short axis of the building. Four pretensioned cables run within these beams, tying the structure together from side to side. Specially engineered wooden slabs span the long axis of the building connecting the beams together and forming the top chord of the beams.

A diagram of the Wooden Empire State Building. (Image courtesy Metsä Wood)

A diagram of the Wooden Empire State Building standing beside the world's tallest tree. (Image courtesy Metsä Wood)

Construction would utilize Kerto® LVL engineered wood, made with young wood glued together to make panels eight feet wide and 64 feet long, of various thicknesses, manufactured by Metsä. The timber engineered materials are said to be stronger than raw wood of similar dimensions and do not require the use of old growth trees according to MetsaWood.com.

Transporting and assembling their pre-fabricated building materials takes less time and money, says Metsä. Trucks can carry five to six times more wood than concrete and connection points and lightness make for a faster onsite assembly.

In the event of a fire, Kerto wood has a notional charring rate of 0.7 mm per minute. As the wood burns, the charred surface insulates the rest of the wood, slowing the burning process. Sprinklers and drywall protect the wood as first lines of defense.

In contrast, the Empire State Building requires full protection by insulation, drywall, stone and other fire resistant materials.

The question remains however, what would using so much wood mean for deforestation? Metsä assures its Kerto wood comes only from “certified, responsibly managed forests that grow significantly faster than they are used. Four saplings are planted for each tree that we use.”

Why Wood can be our ‘Plan B’

The design and construction plan for the wooden Empire State Building was made by Canadian architect Michael Green and his firm, MGA. Equilibrium Consulting, a specialist in timber engineering, provided expertise on structural matters. Metsä Wood’s own material and construction experts rounded out the team.

“I believe that the future belongs to tall wooden buildings,” says Green. “Significant advancements in engineered wood and mass timber products have created a new vision for what is possible for safe, tall, urban wood buildings. The challenge now is to change society’s perception of what’s possible. In fact, this is the first new way to build a skyscraper in the last 100 years.

With Plan B, Metsä and Green hope to open the minds of construction engineers, architects and builders to the possibilities of wood as a key building material. As part of the project, Metsä will show in detail how to build wooden versions of other word-known buildings, like the Roman Coliseum, to be published this year.

Plan B’s concept planning for the wooden Empire State Building is only its first of three phases. Phase two will release technical designs to the public and phase three will see construction. No information concerning construction has yet been released.

For more photos, video and updates on Plan B, visit metsawood.com/planb.

All images courtesy Metsä Wood.

Recommended For You