This is a great question about garage plans and it comes up often. The answer is, probably not, but maybe. It depends on where you build, what the local design parameters are and what kind of plans you use for the project.
WHY ARE ENGINEER STAMPED GARAGE PLANS SOMETIMES REQUIRED? – In most locations plans do not require an engineer or architect’s stamp. However, there are reasons why they would elevate their requirements to requiring professional certification. They are:
- if there are extreme environmental risks for earthquakes, high wind speeds or hurricanes, minimal sheltering or blocking effect from trees and topography causing high wind exposure and poor soil bearing or stability.
- if building site has topography interfering with building on a flat site requiring a special design foundation and/or retaining walls
- if building department has made policy to assign liabilities to state licensed professionals which is usually a political or administrative decision. This usually shows up in extreme high growth-rate communities.
- if the garage plans you plan to submit make no reference to currently applied building codes and show construction that has insufficient or incorrect detailing (such as in low-quality plans) and is not accepted or approved for those reasons.
When a state-licensed professional becomes involved with someone’s project they are then the professional of record for your project in their certification (or stamp). That means that they assume liability for your project’s construction. They would administer the project design, permitting, bidding and, with inspections, supervise construction. Any changes made to the construction would be through change order process. The drawings would also need to include a specifications manual for the project. It is quite involved and expensive. This can usually be done by professional architect or engineer, with both having mandatory liability insurance (also expensive).
Many garage plan providers do not address the building codes and may not be usable unless certified. A money-back guarantee is the best way to protect yourself from loss due to poor quality plans. There is no good reason for this to be the cause requiring certification when normally not needed.
PRESCRIPTIVE OR ENGINEERED COMPLIANCE PLANS – Behm Design is one of the few plans providers that actually address the building code requirements. Our garage plans follow the prescribed building methods, within prescribe limits of size, shape and construction type as provided by the International Building Code (IRC) which is a publication of the International Code Council base on all of their test and research data for construction and safety. This is called “prescriptive” compliance with the IRC. If you design a building which cannot, by design, comply as prescribed then you must use “engineered” compliance which is having a state-licensed professional engineer or architect analyze the forces on the building structure and then make the building strong enough to withstand those forces. The “engineered” approach is also required when the design parameters exceed a certain level of risk – the level beyond which they do not accept the prescriptive approach. This is all in the interest of safety and well-being of building occupants. By design to our standard parameters (seismic – C, wind 100 mph in 3 sec. gust, wind exposure B moderate and snow load of 30 lbs. per sq. ft.) our plans can be used in most US locations.