Plan on making a few updates to spiff up the house? Keep the "few" in mind.

 Two demons wait for unsuspecting homeowners, hoping for their chance to gobble up time and money on new home and remodeling projects. The are called The Ripple Effect and Project Creep.

• The Ripple Effect lurks quietly in the background. Just like the movements on the pond surface for which it's named, The Ripple Effect starts out small and grows, expanding until it engulfs the entire project.
• Project Creep is a silent menace, staying out of sight until it's too late to avoid and putting the whole job at risk.

The Ripple Effect is the remodeling budget's worst enemy and can wreak havoc on small and large projects alike.

A window replacement is a simple, isolated project, right? But the interior and exterior trim must be replaced and painted, and the exterior siding may have to be reworked, especially if the new window isn't the same size as the old one.

And that's just the beginning. Once that window is replaced and the new window trim painted, the rest of the trim in the room looks bad by comparison, and so you decide to paint that, too. A pebble has been dropped in the pond, and the ripples have begun to spread.

What started out as a simple window replacement ends up as the refinishing of an entire room.

In new home projects, The Ripple Effect is more pronounced in open plan designs. With fewer walls to separate spaces, it's difficult to make flooring transitions from one room to another so more expensive flooring materials often cover more of the house. The lack of interior walls also requires a more expensive structural system and makes the placement of duct work and plumbing more difficult.

Don't Make Waves

But The Ripple Effect can be controlled if you take a moment to consider the impact one project can have on other parts of the house. The root of the problem in the window replacement example is that a new standard-sized window won't exactly fit the existing opening, necessitating the replacement of the trim.

But a custom-sized window, carefully installed, might allow you to reinstall the existing trim inside and outside, and avoid The Ripple Effect entirely. Sure, you'll spend more on the window, but you'll save everywhere else and avoid The Ripple Effect.

And in a new home project, careful planning of the room layouts and space adjacencies allows flooring and other finishes to "break" where you want them to.

 Project Creep

Project Creep is a close cousin to The Ripple Effect. Project Creep happens when the extent of the work begins to grow, creeping along at first, until no one seems able to control the spiraling costs.

Older homes, for example, often require building code upgrades when they're remodeled — upgrades that may have little to do with the project itself. When structural loads are changed in any way, for example, the existing structure must be rebuilt or retrofitted to meet updated code requirements. And moving structure usually means reworking the wiring, duct work and plumbing that's been routed through the area.

Project Creep can attack new home projects, too. Sometimes the causes are almost impossible to predict, such as when the excavation of the site uncovers poor soil conditions. Sometimes the cause is an outside force — an architectural review board, for example. But mostly, Project Creep is a result of a difference in expectations between homeowner, builder and architect.

Plan ahead to avoid Ripple and Creep

On any project, start with a clear idea of the level of finish and quality you expect. Don't assume that the architect and builder are in tune with your ideas about finishes. Discuss your expectations in detail and, whenever possible, see the actual finishes and fixtures.

If you're not the detail-oriented type, hire a professional interior designer.

Poor quality drawings cause additional unplanned work during construction and always end up costing homeowners money and time. My firm has been hired many times to correct drawings done elsewhere that contained glaring errors, omitted necessary structural steel or just plain didn't work.

Sloppy drawings are an open invitation to Project Creep

On a remodeling or room addition project, evaluate the feasibility of the project in terms of the impact it will have on parts of the home that you're not intending to remodel. Often, room additions can easily be designed to minimize the effect on the existing structure.

Finally, always have realistic expectations about your project budget and communicate that budget to your architect and builder. When everyone understands the project's financial goals, the chances for success are greatly increased.

Related:

• Nine unconventional ways to improve your home
• Top five requests for home design
• Beware of value-killing renovations

Richard Taylor is a residential architect based in Dublin, Ohio and is a contributor to Zillow Blog. Connect with him at http://www.rtastudio.com/index.htm.

Note: The views and opinions expressed in this article are those of the author and do not necessarily reflect the opinion or position of Zillow.