That qualification is an NVQ4 in building services and assesses such things as supivisory and management. Not many centres offer it as there is a construction nvq3 for supervisors and a construction level 4 nvq for managers which are more popular and do pretty much the same thing. they also complete with the national certificates and higher national certificates in building services engineering which have been around years and therefore recognised by employers.
Be aware this is not a plumbing level 4, level 3 is the highest you can go in a craft specific vocation, any further assesses managing, supervising, accounts etc not installing and thats why it can be cross trade. Its done purely onsite if im not mistaken.
It is the first step to entering management status. A worthy qual and one id like to see take off in popularity.