Commercial Premises New Windows

hi, parents have recently bought a small ex hotel that requires much renovation, all the windows need to be replaced. No decision has been made on exactly what will be run out of the premises when complete as of yet. If it is run as a commercial premises im sure certain bodies including the fire service and hsa willl want a say on standards and specifications, what are they likely to say regarding the installation of windows .ie size of opening, material, the way the window opens inwards or outwards, up or down? who should i approach about this? or does anyone have any knowledge on the issue? thanks…