The choice of whether to buy stock blueprints from an online source or to have them custom designed by an architect can depend greatly on the area you are building and the local building department's requirements. If you choose incorrectly, you can run into unforeseen construction costs that can blow your budget.

Owner builders save anywhere from ten to thirty percent in construction costs by eliminating the expense of a general contractor. But, choosing the wrong home plans can quickly destroy those savings.

As far as upfront costs are concerned, online blueprint sources certainly seem to be the cheapest. And, nowadays, there are thousands of designs to choose from, so you can almost always find something to fit your needs.

What most people don't consider before purchasing an online blueprint, however, is that the blueprints do not come engineered for a specific county or building code. And, if you are building a walk-out basement on a sloped lot, you certainly can't expect a stock online blueprint to account for your particular foundation engineering.

Instead, online blueprints will be designed to meet one general building code, which will not necessarily be the building code for your county.

For owner builders especially, you need to make sure you are intimately familiar with your local building department.

Depending on the requirements of your local building department, you may need considerable additional engineering work. One of the key pieces of information that you will need will be the amount of engineering required to go from an online source that you may be considering to an acceptable set of plans to submit to the county.

The only way to know this is to ask your local county building department what code they follow and compare this to what code the plans follow. If there is extensive work to be done to the online blueprints, it may be cheaper and better to start fresh with a local architect who is familiar with the county requirements.

Owner builders will also need to investigate whether the building department is particularly strict, as it may make more sense to hire a local architect.

Please be aware that changes to online blueprints can get pretty costly if you are making large changes. And one thing that most owner builders fail to understand is that most seemingly simple changes are not nearly as simple as believed.

For example, you may want to move a wall just a foot and think that this is a very simple process. On the surface it is, until you consider the engineering impact on the roof, the foundation, any load-bearing walls, and any cosmetic issues. This is how costs can quickly grow when using online plans.

The best course is to carefully review the floor plans being offered and decide if one will fit your needs exactly as offered. If not, be sure to get a quote to make the changes you want. Compare this to quotes from local architects. My advice to owner builders: if the cost is even close, choose the local architect.

Do not be cheap about your plans. Remember the big picture.

Owner builders who are planning to use a local architect and engineer to design their home will still need to do the same homework with the local building department to know exactly what is needed for submitting the building permit application.

When it comes to hiring someone locally, make sure that the architect has designed homes for that specific county in the past. The more the architect has worked in that county, the better. When you do talk to the county, take the time to ask about the architect you want to hire.

The county plan examiner should be able to tell you right up front what level of quality the architect typically provides. Owner builders save a lot of time and heartache by hiring someone who will provide properly engineered blueprints. This can translate to significant cost savings.

Architects, themselves, don't always provide the engineering for the blueprints. Instead, a lot of architects (especially if they are not really an architect, but a home designer) will provide the home design but outsource the engineering to someone who specializes in residential structural issues.

When you are discussing this issue with your architect, make sure to ask how many times the engineer has provided work for your particular county. It may seem redundant or overly conservative, but if you are building in a strict county, you will be extremely glad you asked the right questions and hired a professional with specific experience in that county.

Anyone building a custom home, whether by being an owner builder or hiring a builder, will need to consider the overall costs of their new blueprints. If you simply choose the plans that seem cheapest up-front, you just might discover the secret, hidden costs the hard way.