A method of preparing a high performance low isocyanate polyurethane top coating effective to protect external architectural surfaces and substantially minimizing applicator exposure to isocyanates, including: providing an amount of compound A chosen from a fluoroethylene vinyl ether (FEVE) moiety of formula (I); providing an amount of Compound B chosen from a silane functional isocyanate of general formula (II); where compound A and compound B are present in a stoichiometric ratio of 1:1; providing an effective amount of a catalyst of compound C; introducing compounds A and B into a reaction vessel and stirring the compounds in an inert atmosphere at a predetermined temperature and a predetermined time; where the resultant silane functional FEVE resin is substantially free of unreacted isocyanate.