"beyond existing" is a correct and usable phrase in written English.
You can use it to refer to something that goes beyond the existing state of things. For example, "The new design goes beyond existing approaches to sustainability."
It is through partnerships that NGO efforts are reaching beyond existing government initiatives.
Farron's pledge to oppose the bedroom tax consciously goes beyond existing Liberal Democrat and coalition policy.
Democratic policy experts say his willingness to bargain beyond existing public proposals may be ebbing.
Detractors say a functional cure would not offer much beyond existing drug therapy.
Elsewhere, the peshmerga advanced somewhere between 20km and 40km beyond existing Kurdistan and deep into federal Iraqi territory.
On the rosier side, he was a stickler for safety, setting standards that went far beyond existing maritime regulations.
"In more impersonal settings, like cities, matrimonial advertising through newspapers could forge new links and expand the range of available prospects beyond existing networks".
But proposals to widen the scope of individuals covered by pay rules were rejected as they go "significantly beyond existing international standards".
Attempts to enshrine shared values in a charter are still being discussed by officials, but the final product is unlikely to go beyond existing international commitments.
… The link between inspiration and creativity is consistent with the transcendent aspect of inspiration, since creativity involves seeing possibility beyond existing constraints".
The ViaSat system will enable users to go beyond existing services that basically offer Internet browsing and e-mail, he said.
