Best Plastic Window Boards of 2026

Corey Phillips Avatar
Corey Phillips
Last Updated: 4 Feb 2026

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Plastic window boards are a popular alternative to traditional wooden window sills. Made from durable PVC, these boards are designed to withstand the elements and resist rot, making them a low-maintenance option for homeowners. Available in a range of sizes and colours, plastic window boards are easy to install and can be cut to fit any window opening. They are also easy to clean and do not require painting or staining, making them a cost-effective choice for those looking to update their home's interior or exterior.

At a Glance: Our Top Picks

225mm White UPVC Window Board by Eurocell Cover #TOP 1
225mm White UPVC Window Board by Eurocell
ftb score rating icon 9.8
300mm White UPVC Window Board by Eurocell Cover #TOP 2
300mm White UPVC Window Board by Eurocell
ftb score rating icon 9.7
White UPVC Window Board Cover 1.1m Long Cover #TOP 3
White UPVC Window Board Cover 1.1m Long
ftb score rating icon 9.5

Top 6 Plastic Window Boards

#TOP 1

225mm White UPVC Window Board by Eurocell

CB22564_2.5
225mm White UPVC Window Board by Eurocell Cover
225mm White UPVC Window Board/Cill Cover 2.5m Long 9mm Thick Plastic Window Sill Capping

The Eurocell Window Board is designed for quick and easy fitting, requiring minimal tools and no mechanical fixings. This means you can effortlessly install it without any hassle. Its long-lasting protection is tough and resistant to warping, ensuring your window sill remains in great shape over time. With a maintenance-free design, you can simply wipe it clean without the need for painting, saving you time and effort. Additionally, it comes in various colours and widths, allowing you to choose the perfect fit for your individual application.

What We Like
Easy to install
Durable and warp-resistant
Maintenance-free surface
Variety of colours available
#TOP 2

300mm White UPVC Window Board by Eurocell

CB30064_1.25
300mm White UPVC Window Board by Eurocell Cover
300mm White UPVC Window Board/Cill Cover 1.25m Long 9mm Thick Plastic Window Sill Capping

The Eurocell Window Board offers a quick and easy fitting process, requiring minimal tools and no mechanical fixings. This means you can install it without hassle. It provides long-lasting protection, being tough and resistant to warping, ensuring your windows remain in great shape. The board is also maintenance-free, featuring a wipe-clean surface that eliminates the need for painting. Additionally, it comes in various colours and widths, allowing you to choose the perfect fit for your individual application.

What We Like
Easy installation
Durable and warp-resistant
Maintenance-free surface
Customisable colours and widths
#TOP 3

White UPVC Window Board Cover 1.1m Long

White
150mm Width
White UPVC Window Board Cover 1.1m Long Cover
White UPVC Window Board/Cill Cover 1.1m Long 9mm Thick Plastic Window Sill Capping (150mm Width)

The UPVC Window Board Cover offers quick and easy fitting, requiring minimal tools and no mechanical fixings, making installation hassle-free for you. Its long-lasting protection ensures that the board remains tough, colour-safe, and resistant to warping, providing durability over time. You'll appreciate the choice of width, allowing you to select a product tailored to your specific needs. Additionally, the maintenance-free feature means you can easily wipe the surface clean without the need for painting, saving you time and effort.

What We Like
Easy installation
Durable and colour-safe
Customisable width options
Maintenance-free surface
#TOP 4

Eurocell 9mm Thick Plastic Window Sill Trim

TPVC
White
240mm
Eurocell 9mm Thick Plastic Window Sill Trim Cover
Bullnose Capping Cover 9mm Thick Plastic Internal Window Sill Trim (2.5) - 240mm, White

The Eurocell Window Sill Trim offers quick and easy fitting, requiring minimal tools and no mechanical fixings, making it a hassle-free option for your home. Its long-lasting protection means it is tough, colour-safe, and resistant to warping, ensuring durability over time. You can choose from a variety of widths to suit your specific needs, providing flexibility for different applications. Plus, the maintenance-free surface only needs a simple wipe clean, saving you time and effort on upkeep.

What We Like
Quick and easy fitting
Long-lasting protection
Choice of width
Maintenance-free surface
#TOP 5

175mm White UPVC Window Board by Eurocell

CB17564_1.25
175mm White UPVC Window Board by Eurocell Cover
175mm White UPVC Window Board/Cill Cover 1.25m Long 9mm Thick Plastic Window Sill Capping

The Eurocell Window Board offers a quick and easy fitting process, requiring minimal tools and no mechanical fixings. This means you can effortlessly install it without the hassle of complicated equipment. Its tough, colour-safe material provides long-lasting protection against warping, ensuring your window sill remains in great condition over time. The maintenance-free design features a wipe-clean surface, eliminating the need for painting and saving you time on upkeep. Additionally, the variety of colours and widths available allows you to choose a product that perfectly suits your individual application.

What We Like
Easy installation
Durable and resistant to warping
Maintenance-free surface
Variety of colours and widths
#TOP 6

200mm White UPVC Window Board Cill Cover with End Caps

Capping Board
White
200mm White UPVC Window Board Cill Cover with End Caps Cover
200mm White UPVC Window Board Cill Cover and End Caps 2m Long 9mm Thick Plastic Window Sill Capping

The White UPVC Window Board offers quick and easy fitting, meaning you won't need many tools or complicated fixings, saving you time and effort. Its tough, colour-safe surface protects your window sill from damage and warping, ensuring it looks good for years. The board is maintenance-free, so you can simply wipe it clean without worrying about painting or upkeep. With a 200mm width, it fits well for standard window cills, providing a neat and durable finish to your window area.

What We Like
Easy installation
Durable and colour-safe
Maintenance-free surface
Includes end caps
Buying Guide Image

Frequently Asked Questions (FAQs)

1. Can you replace plastic window sills?

Exterior Window Sill Replacement By covering your wood with PVC window sill replacement, you eliminate the need to paint or replace your wood ever again. Your window sill will look like new even if you have some wood rot - repair the damaged wood with filler, then install the vinyl cover.

2. What are window boards called?

A window board is a piece of wood (or in our case premium MDF) that is found underneath a window. They are commonly referred to as window cills.

3. What is the difference between a window sill and a window board?

The big difference between window cills & window boards (pictured below) are one is on the outside of the building, the other is fitted on the inside of the house. They are similar but both perform very different roles and are often confused with each other.

4. What size are window boards?

18mm And 25mm Thickness As standard, the only thickness options you can choose for window boards are 18mm and 25mm.

Editor's Notes

During our plastic window board research, we found 84 plastic window board products and shortlisted 6 quality products. We collected and analyzed 5,570 customer reviews through our big data system to write the plastic window boards list. We found that most customers choose plastic window boards with an average price of £13.52.

The plastic window boards are available for purchase. We have researched hundreds of brands and picked the top brands of plastic window boards, including Eurocell and more.

Written by
Corey Phillips Avatar

Corey Philips is an electrician and lighting expert. He graduated from the University of Birmingham in 2012 with a Bachelor's degree in electrical and electronics engineering. Corey is a specialist contractor in lights. He sells and installs and recommends lights and lamp sheds, and other lights accessories. Aside from that, Corey is vast in installing and maintaining electrical appliances like air conditioners, water heaters, and the likes.