Single storey

Britmet lightweight roofing. They do roof coverings in the style of other tiled roofs. Check them out

You could reply with something like this: At 10° I personally wouldn’t recommend a conventional tiled roof unless you’re using a manufacturer-approved low-pitch system and following every part of their specification. Even then, you’re right on the limit and there’s very little margin for error. Any small installation defect can become a leak later on. If this were my job, I’d be recommending a warm roof with either a high-quality GRP system (such as Restec/Flexitec), EPDM, or standing seam metal. They are all designed to perform reliably at low pitches and will generally give a far better long-term solution than trying to force a tiled roof to work where it’s not really intended. If keeping the appearance of tiles is important, there are a few low-pitch tile systems available from manufacturers like Marley or Sandtoft, but I’d only install them if the roof pitch, headlap, underlay, battens and detailing all complied with the manufacturer’s guidance. I’d also be checking junctions, valleys and abutments very carefully, as these are usually where problems start. Reliability would be my priority over appearance. It’s much easier to explain why you chose the correct roofing system than to explain why a 10° tiled roof is leaking a few years down the line.