Holding company discount to NAV

I have to calculate the discount to NAV a private equity holding company should trade at. I have found that one of the main reasons a holding company trades at a discount to NAV is because of the extra layers of fees (management fee, performance fee etc.) charged. To determine the discount to NAV I thus decided to discount the future expected fees to a present value. I have normalised the management fees, secretarial fees, outperformance fees etc to an annual basis and assumed perpetual growth rates for each and weighted them to obtain a weighted average perpetual growth rate. The problem now is that because private equity generally offer higher returns, management and performance fees grow at a very high rate and thus the growth rate is higher than WACC. I understand that other factors also affect the discount rate such as liquidity etc. Please help.