Triglass plc has three types of capital. The market capitalization of its equity is £20m. These ordinary shares have a beta of 0.9, as measured over the past five years of monthly returns which may be taken as the appropriate adjustment to the average risk premium. The current risk free rate on government bonds is 4.5 per cent. The historic equity risk premium is 5 per cent per year. The market value of its irredeemable non-participating non-convertible preference shares is £5m and the rate of return being offered is 7.5 per cent per year. The debt of the firm amounts to £15m and costs 6.5 per cent per year before allowing for tax shield benefits. The corporation tax rate is 30 per cent. Calculate the WACC for Triglass plc.