A lesson that the average retail investor has heard time and again is that even a fraction of a percentage in higher fees can kill your returns. The personal finance site Nerdwallet calculated the 30-year difference in a personal retirement account of $13,200 between an index fund at 0.09% fees and a mutual fund that charges 0.82%.

That may have played out on a consumer level, but for accredited and institutional commercial real estate investors, the principal—and the interest—hold true as well. A new analysis by alternative assets data provider Preqin shows that when it comes to investments through private equity, management fees hide the true dollar cost.

As the analysis notes, fees are a point of contention between general and limited partners in private equity funds. "LPs' calls for greater transparency have become increasingly loud as they look into what exactly they are paying for and how that is impacting bottom-line, net returns," Preqin says. "GPs counter this by arguing that their funds' outperformance of public markets justify fees to yield-hungry investors. Regardless, investors' demands are likely to get louder as private equity and venture capital assets approach the $7tn assets under management (AUM) milestone."