The banner of ‘semi-commercial’ covers a wide range of properties. Any property that comprises of both a commercial element and living accommodation will be classed as semi-commercial.
Some lenders charge lower rates for semi-commercial properties than are charged for fully commercial buildings. Where this is the case, there are sometimes splits in the ratio of residential to commercial space needed to secure the lower rate.
Another point that could exclude your property from being eligible, is where there is a single access to the property, meaning it could only be occupied by a single tenant or business owner.