All buildings erected or constructed within any B1 downtown commercial district shall be constructed such that all exterior walls and interior load bearing walls consist of masonry design adequate to support all structural elements and provide the required fire ratings as indicated in the building codes adopted by the city of Spring Valley. Modifications to this type of construction will not be permitted unless the property owner and contractor first obtain written permission from the Spring Valley city council to modify the restrictions provided herein, after review and recommendation by the Spring Valley city engineer, the Spring Valley building inspector or the Spring Valley fire chief, as appropriate. (Ord. 1408, 2-2-2009)