Be proportionate to the proposals and their likely impact; for example, a major restoration scheme will need more detailed consideration than an application to paint a previously unpainted building.
Bod yn gymesur â'r cynigion a'u heffaith debygol; er enghraifft, bydd angen rhoi ystyriaeth fwy manwl i gynllun adfer mawr nag i gais i baentio adeilad sydd heb gael ei baentio o'r blaen.