Construction An Addition

With our great Arizona weather, any time is a good time to add to an existing home or building.

While there are many factors that drive a decision to add on, the most common reasons are a growing family, financial considerations, having to care for an aging parent or loved one, or just needing more space for that new gaming system!

Hire a good architect or designer!

These professionals will help you determine what kinds of zoning ordinances govern things like the addition size, the proximity of the addition to property lines, streets and alley ways (setbacks) and NAOS considerations.  While zoning ordinances can be viewed as real irritants, they are designed to keep the town or city in which you live safe, attractive and manageable.

Some things to consider:  Is this an older home that is governed by historical preservation ordinances?  Does the addition have to comply with the older style aesthetics of construction?  Is there a homeowner’s association that requires an architectural review?

What types of structural considerations need to be made?  Hire a Registered Engineer!

Often, constructing an addition means subtracting some parts of the original structure.  What walls can be moved or removed and how can the roof structure be modified so as to not make the structure unsafe?  If you are changing the roof surfacing from asphalt shingle to concrete tile, for example, a Registered Engineer must make measurements and perform a load calculation to determine if reinforcement of the roof structure is needed.  What foundation changes are needed?

Having a well thought out plan is vital.

Which way do doors swing so as to not interfere with traffic flow inside the house?  Where do we place light switches?  How does the addition tie into the existing structure and are any means of emergency egress being eliminated?  What about window and door placement….in Arizona, this is an important consideration as south and west facing windows can be extreme sources of radiant heat gain in the summer.

In Arizona, having an adequately cooled addition is extremely important.

Does the added space require a larger size heat pump or air conditioning unit?   In general, in this area of the Southwest, a ton (12,000 BTU’s) of air conditioning is needed for every 400 to 500 square feet of livable floor space.  Knowing this, is it more economical to replace the existing unit with a larger one or is adding an additional zone make more sense?  A Registered Engineer is the professional to ask for answers to these questions.

“Surpriiiiiiiiiiiiiiise, surpriiiiiiiiiiiiiiise”, as good old Gomer Pyle used to say.  The best way to handle surprises is to expect them.

While building that addition you may not find a Monet or a signed Elvis Presley guitar hidden in a wall, however, you should you expect to find rotted wood, termites and other critters, leaks, or who knows what.  Just remember, the vast majority of these things can be handled….don’t panic.

The list of things that need to be considered when building an addition may seem endless, however, don’t hesitate to call in a Professional Engineer who can help answer many of your questions and concerns.


  • Zoning ordinances, code considerations, historical and other guidelines.
  • Structural survey of the framing and foundation.
  • Interior layout, wall switches, door swing direction, roof lines, etc.
  • Heat pump or air conditioner sizing.
  • Expect surprises