In deciding upon applications for historic review certificates, the Commission shall keep in mind the main purposes of this section and shall consider, among other things, the historical and architectural value and significance, the general design, arrangement, texture, material and color of the building, site or structure and appurtenant fixtures in question, the relation of such features to similar features and buildings in the immediate surroundings and the position of such building, structure or site in relation to the street or public way and to other buildings, structures and sites. Using the above guides, yard and lot requirements shall be individually established by the Commission as provided for by the Schedule of District Regulations of this chapter.