Polymer based shutters are a terrific solution for smaller windows that will be subject to moisture. Regardless of finish ALL shutters made of any type of Wood or MDF are susceptible to water damage. Poly shutters will not suffer from water damage.

Points to consider:

Poly shutters are considerably heavier than a natural wood product.

Although many companies sell it as a “warp free” product, it can tend to “sag” which will not be covered in their warranty.

Many times Poly shutters are not painted.  They are left in their extruded finish.  This finish will tend to yellow, depending on the quality of poly material is used.

Max panel width is 30″ before warranty is void.  This is due to its span tolerance.  This means a 36″ window should not be done in 1 panel and a 72″ panel should not be done in less than 3 panels.  This may not line up with existing window panes and obstruct much of your visiblilty.

Panels can only be 60″ tall before they require a center rail, splitting your shutter into 2 halves and possibly putting a rail right at eye level.