Researchers find that sustainable construction only costs 2 to 4 percent more, and can slash energy bills.
By Zafrir Rinat | Apr.11, 2013

Green construction is known to save resources, reduce greenhouse gas emissions and improve urban quality of life. So why aren’t cities going green faster? One of the biggest reasons is uncertainty over the costs.

The Israeli Green Building Council – a member of the not-for-profit World Green Building Council dedicated to promoting sustainable construction – recently published a study tackling the issue in Israel’s residential market. The analysis, written by economists Hagai Kot and David Katz of the University of Haifa, examines two apartment buildings: one built by Hanan Mor in Nes Tziona and the other by Shikun & Binue of the Arison Group in Netanya.

Both construction companies regularly plan and build green homes in Israel.

To qualify as green, a building must take certain environmental considerations into account, including energy savings and the use of recycled and non-toxic materials. For instance, natural light may be used for heating, thermal insulation may go into walls, water and electricity may be conserved in various ways and construction waste may be reused.

Buildings are signficant contributors to water and energy consumption as well as greenhouse gas emmisions and large consumers of mining and quarrying materirals.

The council’s report focuses on building materials, comparing the costs of the green materials the builders reported using – verified by outside experts – to those of traditional materials.

Green materials were found to have added NIS 685,000 to the cost of the Nes Tziona building and NIS 918,000 to the Netanya building – an estimated premium of just 2 to 4 percent. Per apartment, the green materials cost an extra NIS 26,000 in Nes Tziona and NIS 12,000 in Netanya. Sixty percent of the additional costs came from energy-saving measures, particularly thermally insulated walls and windows.

While the study shows that developers and home buyers don’t have to pay much more to go green, the authors, Kot and Katz, note that the materials used in green construction vary widely, meaning costs remain unpredictable.

The Israeli standards for green construction have also been made stricter since the buildings in the study were completed; but any added expenses may be offset by improvements in green construction methods.

Another study recently published by the World Green Building Council found that green construction leads to significant savings on expenses, like maintenance, water and energy. Such savings can reach 30 percent in the U.S. and over 40 percent in New Zealand.

Improved ventilation and lighting and reduced exposure to pollutants, like toxic fumes produced by common building glues and thinners also make green buildings healthier, according to the study.

Yet architects and planners say green constructions’ biggest benefits are achieved in the collective by neighborhood planning that includes green areas, bike paths, convenient recycling infrastructure and the use of treated water.

In the meantime, they say modifying existing buildings can yield quick results. In Israel, green retrofitting is eligible for subsidies through National Plan 38, which promotes reinforcing existing buildings against earthquakes. Local authorities and the national government also offer expedited licensing and permitting and incentives to green developers.