Insulated modular roof system

An insulated modular roof system for a roof structure, comprising:

• a plurality of modular panels suitable for installation onto the roof structure;
• and
• a water-proof membrane,
• wherein each of said plurality of modular panels comprises:
• a first planar member suitable to accept at least one fastener therethrough so as to allow at least one of the plurality of modular panels to be mounted to the roof structure;
• an insulating layer covering substantially all of the first planar member;
• and
• a second planar member suitable to cover substantially all of the insulating layer;
• wherein the water-proof membrane is provided in sections on each of said plurality of modular panels, each of said membrane sections having length and width dimensions larger than the length and width of the first planar member so as to allow adjacent membrane sections to overlap.