A section 106 agreement states that an ancillary building cannot be used as a dwelling. An application for a lawful development certificate (LDC) is subsequently submitted, demonstrating that the use of that dwelling is lawful as it has been used as a single dwellinghouse for at least four years. Can the application for an LDC be used to confirm compliance (or lack thereof) with the planning obligation? Assuming not, is that enough of a ground to refuse the application? If the LDC is granted, can enforcement under the section 106 agreement still be taken?