A client asked this question yesterday, and while it seems simple, it is actually complicated. Let me walk you through the issues.
The simple answer is sometimes it is a good idea to replace an iron fence with vinyl, sometimes not.
The issue is driven by concerns about two different issues – the application (location), and the cost.
Application: Vinyl vs. Iron Fencing
Vinyl fencing is good in a perimeter application, especially in a salt-air environment or location where it gets hit with irrigation over-spray on a regular basis.
Vinyl is not good in a safety application (pool perimeter or balcony), where strength and rigidity is important. Vinyl is also not good where it invites vandalism (along a busy sidewalk), as it cracks and gets holes poked in it pretty easily, and can be spray painted by vandals (unlike an iron fence!).
In addition, vinyl fencing presents a very different “look” than ironwork: it is very visible, while an ironwork fence is primarily see-through.
Cost: Vinyl vs. Iron Fencing
In a dry environment, an iron fence can last a very extended period of time… almost indefinitely. But it takes regular repainting, typically every 3 to 5 years. Vinyl has a pretty solid 30 year useful life and doesn’t require painting, but it does begin to look dull and faded eventually as it gets past the 20 year old point.
Painting ironwork costs roughly $8-10/LF, so you spend about $50/LF in six paint cycles over approximately 30 years, which happens to be about the same cost and useful life as vinyl fencing! So there is no clear winner on a price basis (presuming ironwork doesn’t need to be replaced… which means a dry air, well-cared-for application).
So it is not an easy “either-or” answer. It depends on the application (location) of the fencing, the aesthetic sensibilities of the association, and the cost. When you look at the cost issue, in an ironwork vs vinyl comparison, vinyl is not a “duh, it’s cheaper” solution.