Nordic — Energy efficiency has become a critical driver of value in Germany's commercial property market, according to new research from energy performance specialist Re:sustain. The study found that every fund manager surveyed already holds so-called "stranded assets" within their portfolios, with some properties suffering value declines of up to 40 per cent. The findings suggest investors are increasingly shifting their focus away from large-scale refurbishment projects and towards digital technologies in a bid to protect asset values and meet tightening sustainability requirements.