I don't believe there is any additional cost to this. It's a matter of the construction industry starting to embrace this in their ongoing culture in the same way as I've described that health and safety is now embraced in the ongoing culture with dramatically reduced fatalities, and green building design has been embraced in the culture. These haven't cost anything. In fact, a life-cycle cost analysis would show that these kinds of measures and community benefits will provide dramatic savings to the public purse as we reduce some of the other issues around incarceration and health issues.
On November 3rd, 2016. See this statement in context.