Types of Exterior Window Sills: A Complete Guide

Choosing new exterior window sills for your home is an important decision. The right sill material can enhance your home’s architecture, provide insulation, and withstand the elements.

When selecting a window sill, key factors to consider are durability, weather resistance, maintenance requirements, cost, and visual appeal. You’ll want to choose an option that offers strength, longevity, and moisture protection. However, aesthetic preferences also come into play. The style and color of your sills should complement your home’s exterior.

Metal Window Sills

Metal is a go-to choice for many homeowners due to its strength and durability. Let’s look at two common metal options.


Aluminum is one of the most popular metals used for exterior window sills. It offers excellent durability and weather resistance. Aluminum does not rust or corrode when exposed to the elements.

Benefits of aluminum window sills include:

  • Extremely durable and long-lasting
  • Requires very little maintenance since it doesn’t need painting
  • Available in a variety of colors and finishes like mill, clear anodized, bronze, white, and wood grain
  • Lightweight yet strong
  • Provides great insulation

The main downside of aluminum is that it tends to be more expensive than other metals like steel. But overall, its resilience and low maintenance make it a fantastic choice for window sills.


Steel is another common metal used for window sills. It is an affordable option known for its durability.

Benefits of steel window sills:

types of exterior window sills
  • Economical price point
  • Can support heavy weights
  • Available in a range of colors when painted

Potential drawbacks include:

  • Prone to rusting when exposed to water and moisture
  • Requires frequent painting to maintain appearance and prevent rust

Proper surface preparation and consistent repainting are key for steel sills. Overall, steel provides an affordable metal option if proper maintenance is kept up.

PVC Window Sills

Let’s move from metals to plastics. A popular choice here is PVC.


PVC stands for polyvinyl chloride. It is a versatile, lightweight plastic used for many home building products like pipes, gutters, and window sills.

Here are the pros of PVC window sills:

  • Budget-friendly price point
  • Available in a wide range of colors and textures
  • Resists moisture
  • Minimal maintenance required

Potential cons include:

  • Prone to expansion and contraction
  • Can warp or crack over time
  • Not as strong or rigid as metal

PVC is best suited for protected areas that don’t endure extreme weather shifts. With proper installation, PVC can be a quality, affordable sill option.

Stone Window Sills

For a natural, upscale look, many homeowners opt for stone window sills. Let’s explore some of the most popular stone types.


Granite is known for its elite durability and visual appeal. It is an igneous rock formed from cooled magma. Granite can last decades with minimal maintenance. It comes in stunning colors and patterns from grays to reds.


  • Extremely long lifespan
  • Withstands all weather conditions
  • Available in diverse colors and finishes


  • Heavy weight requires reinforced walls
  • Higher price tag than other stones


Composed of recrystallized minerals, marble is another elegant option valued for its beauty. It comes in an array of colors and patterns.

Benefits include:

  • Striking, polished appearance
  • Can be customized with unique veining, colors, and finishes

Downsides to marble:

  • Requires sealing to prevent staining
  • Easily etched by acids
  • Softer and less durable than granite

With proper sealing and care, marble sills add timeless elegance to a home’s exterior.


Limestone is a classic sedimentary rock known for its versatility. It comes in various colors and textures based on mineral composition.


  • More budget-friendly than granite or marble
  • Offers unique nuances in coloring and veining


  • Porous and prone to staining if unsealed
  • Softer than other natural stones

With sealing, limestone can provide an elegant stone look at a more affordable price point.


Sandstone is composed of compressed quartz grains, giving it a natural, irregular aesthetic. Its colors range from red to gray.


  • Natural, rough-hewn appearance
  • Budget-friendly compared to other stones


  • Prone to crumbling since it is fairly soft
  • Requires sealing

Sandstone provides rustic charm at an accessible price if properly sealed and maintained.


Slate is a foliated metamorphic rock known for its layered, textured appearance. It comes in shades of purple, green, black, and gray.


  • Withstands weather well
  • Unique colors and textures


  • Can crack or flake over time
  • Requires sealing

With protective sealing, slate lends timeless beauty and dimension to exterior sills.

Brick Window Sills

For homes with brick exteriors, matching brick window sills can provide cohesion. Brick has a classic, natural appearance.


  • Complements existing brick homes
  • Traditional, charming look


  • Can deteriorate faster than other materials
  • Rough surface prone to chipping
  • Can allow moisture penetration

Sealing and proper sloping are key for utilizing brick on window sills.

Concrete Window Sills

For a modern, sleek look, concrete is growing in popularity. This composite of cement, aggregates, and water can be molded and stained in diverse ways.


  • Very durable and impact resistant
  • Can mimic stone, wood, and other materials with stains
  • Provides great insulation


  • Prone to cracks that allow water intrusion
  • Difficult to patch cracks seamlessly
  • Color fades over time

With proper installation and sealing, concrete offers versatility and contemporary appeal.

Composite Window Sills

Newer on the scene are composite window sills, made by blending materials like wood fibers, polymers, resins, and stone dust. The result is a durable, resilient manmade product.

Advantages of composites:

  • Require minimal maintenance
  • Resist moisture, rotting, and insects
  • Can mimic wood or stone


  • Limited style and color options
  • Higher cost than vinyl or wood

Composites provide great durability with limited maintenance needs.

When reviewing the many options for exterior window sills, keep these key factors in mind:

  • Durability: Pick a material that can withstand your climate’s temperature swings, moisture, UV rays, and wear-and-tear.
  • Appearance: Choose a style that complements your home’s architecture and exterior materials.
  • Maintenance: Lower maintenance materials like aluminum and composite save time and costs long-term.
  • Budget: Select an option that fits within your budget while still offering sufficient longevity.
  • Performance: Ensure proper insulation, drainage slopes, and sealing to prevent interior water damage.

Installing new exterior window sills provides an opportunity to enhance your home’s aesthetic appeal while replacing worn materials. Take time to research the ideal style and material for your needs and budget. With proper installation and care, your new window sills can provide long-lasting beauty and protection.

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