Having a custom drawn designed house means a professional architect applies his skills limited to the individual homeowner's needs or what they have in mind. Factors considered in such a situation are the size of the site of construction, ideas of the individual homeowner, population around the area, and the nationally and locally existing building code plans. Time is also a considerable factor for completion of a custom designed house.
Having been in the business for more than 30 years, we have seen a large number of house plans which looked good at first glance. However, upon closer examination, many of these plans were found to be lacking large amounts of needed information. If a house plan is not easy to navigate or is not thoroughly detailed, then the builder is left to guess at the designer's intentions. This often means that he will "pad" his bid to make sure that he covers any unknown construction costs that may arise.
Small house plans are normally defined as houses with less than 1800 square feet, excluding a basement. These house are also space efficient and less expensive to build on a small plot of land.
Moreover, you can save a lot on construction cost when a using a stock house plan. The advantage comes when you purchase a plan that had been previously used. This means all costs have been put into consideration, therefore, one can easily know what to expect come time for the actual construction. This gives an accurate budget, a small construction span, and efficiency due to prior arrangements during the recent use of the house plan.