Very simply because the word implies a custom house designed to meet your desires. Most often, it is the result of being unable to find the house you want where you want it. Custom house design provides to satisfy both.
Many lane builders will not make any changes or strictly limit them. The materials are predetermined but the color selections are generally very generous and satisfy most people. Most homes are energy efficient, but some builders will be at least what the code or market allows. Upgrades are usually available but not always. A custom home will allow total control and selection if this is preferable.
This path will require non-perceptible design fees in the purchase of a new or existing home. The reality is that there is a design fee or value in every home that is reflected in the purchase price or the market value. Leaf builders who build the same homes over and over on parcels of land can reduce the cost of the lot and the design per house. They can also save on materials and work because of the scale.
Custom homes can not compete with that at the price of a square foot. They do however provide other benefits, including possibly saving money. The most common solution to get everything you want is to buy a house that has more than you want in more footage. It's there that you really need to consider what you want and what you need. If you pay for a game room, you do not really need to get the other parts and features you want, there is a cost associated with that.
I recently designed a house for friends that allowed them to save about $ 30,000 by cutting sequences. They had the property and had chosen plans for a plan book and wanted my opinion before buying the plans. In discussing the design, what became apparent was that there were larger rooms than needed and a formal dining room completely useless. We decided it was worth it for a custom design. The design of the plan book was over 2700 square feet and the new custom home design was less than 2400. As good friends, they paid what the plan book would have cost them. Design costs vary, but for a design-only contract that does not include job monitoring as the builder anticipates, the savings for a typical customer would still have been greater than $ 20,000.
Existing stock plans can be a great solution if they are exactly where you want them to be. But like buying a new or existing home if you are paying for rooms or sequences, you do not need existing plans may not be the best choice or the most profitable.
Custom home design is not for everyone but I hope this knowledge will help you decide if it is the right choice for you.