The average residential home has about 400 square metres of exterior wall area. At $30m2, a home of that size would cost about $12,000 to fully render. On the high end of the scale, rendering would cost $20,000 at $50m2. The cost is significant, but the results can be stunning.Top professional renovators put rendering high on their lists of ways to add value to a brick home.t $30m2, a home of that size would cost about $12,000 to fully render. On the high end of the scale, rendering would cost $20,000 at $50m2. The cost is significant, but the results can be stunning. Top professional renovators put rendering high on their lists of ways to add value to a brick home.