Daryo May 12, 2019:

Not that it would change anything to the translation for:

À défaut de renonciation par le BENEFICIAIRE à se prévaloir de cette condition suspensive,

but "cette condition suspensive" IS NOT the previous part

"Le BENEFICIAIRE est averti que seule la délivrance d'une autorisation d'occuper le sol, libérée du droit de retrait de l'autorité qui l'a octroyée et purgée du recours des tiers, confère un droit acquis à aménager et/ou à construire."

That is more a disclaimer - a warning to the potential buyer in the sense that "be aware that you will need to obtain appropriate planning permissions, don't come back later complaining about it" it DOESN'T say "you can renegade on your promise to buy if you don't get planning permission"

which also fits with

"la non délivrance de ce certificat rendra les présentes caduques."

i.e. "cette condition suspensive" is to be materialised in the form of some kind of "un certificat" not "une autorisation d'occuper le sol".

"la condition suspensive" describing what kind of "certificat" is a pre-condition for the sale must have be enunciated before the part "Le BENEFICIAIRE est averti que ..."