Are there alternative options for an external SVP?

We are renovating our house, adding two additional bathrooms. There is an existing SVP at the end point of the drainage system. The two new bathrooms connect to the drain through a new connection at a different point [downstream].

Is there an alternative to a second SVP? This would have to be 2m above roof to meet regs regarding window clearances due to the gable end.

If u have one open stack then any more added stacks only require a air admitance valve on them( DURGO VALVE) If internal the valve needs to be 1m above the lowest appliance but when there outside i allways bang em on top of the junction & our b.c.o is happy with that.