Prefab housing units made from invasive trees

A new project is eliminating invasive tree species by using them to build affordable, prefabricated housing

Spotted: The Molucca albizia tree was brought to Oahu in 1917 as part of a re-forestry project. The trees are beautiful, but they grow very rapidly, soaking up the water that the native flora depends on. Now, University of Hawaii architect graduate Joey Valenti has found a sustainable use for the destructive Albiza — prefabricated, low-cost housing units made entirely from the trees.

The design for Valenti’s prefab accessory dwelling units is based on indigenous South Pacific architecture styles, such as the round thatch-roofed Samoan fale. The dome-like structure uses wooden louvre walls to allow natural airflow in, reducing the need for air conditioning. They are also covered with a waterproof canvas roof sourced from a local manufacturer.

Albiza trees produce a soft, low-density wood, and Valenti used novel techniques in order to strengthen the timber for building. He glued boards into layered panels, which were then shaped into arches and beams. This created a type of cross-laminated timber, where the wood was laminated in the same direction.

Shortage of affordable housing is an endemic problem in many areas of the world — as is the need for sustainable housing. At Springwise, we have seen a number of innovative approaches for solutions to both problems. These have included prefab homes on stilts, and floating homes for coastal dwellers.