Based on the expected difficulty of the job the cost per square foot could vary. For smaller remodels, a cost per square foot may be given to start, with additional costs added in revisions as the process goes on. I am not so sure how common this is but I do think many architects use this system. Costs Per Square Foot. However, many experienced architects could also charge $10 per square foot, which is quite a significant amount. Nearly, you have to spend almost $1000 to $5000 per 1000 square feet of area. Or an architect might agree to design a 25x25-foot room addition for $5,000-$10,000, or a 3,000-square-foot custom home for $50,000-$75,000 or more, no matter what the final construction price is. On an average basis, this cost will range from $1.25 to $5 per square foot area. the set a rate and based on the size of the job they get paid accordingly. Well, such a fixed fee is typically small for small-scale projects. When an architect needs to work out the design or choose the building materials before calculating the overall costs of a project, this pricing method is particularly useful. Generating costs per square foot is a pricing method often employed in small projects. Like new builds, the cost per hour ranges from $150 - $400 , while the cost per square foot ranges from $2 - $10 , depending on how extensive the remodel is and the architect’s involvement. For a very general estimate, it is easiest to think about the cost to build a house per square foot, or more usually, the cost per square metre. Some architects charge based on a set cost per square foot. COST PER SQUARE FOOT. Architect costs. Breaking it down like this, at the lower end of the spectrum, a new build house might cost as little as £1,400 per square metre.