Timber Windowbox

Window boxes are an exterior design feature that serve as containers for colourful miniature gardens. You can showcase a harmonious combination of vivid blooms, bright blossoms, and verdant greens that will surely add a little bit more design, colour, and texture to your home. 

These boxes are undeservingly overlooked, but they make a massive difference to your overall hardscape design and make your home stand out on the block, especially when they are strategically placed. 

It’s essential to consider the size when choosing the appropriate window boxes. A good rule of thumb is to match your flower box’s width to your window’s width, use smaller flower boxes on smaller windows, and opt for larger boxes on oversized windows.

Choosing the right window box to your home can add curb appeal, but there are many factors to consider before making a final decision. You need to take into account the box’s materials, size, and depth. Use this as your guide to help you determine the perfect size for your window box.

How Do I Choose the Ideal Window Box Length?

Your flower box’s style and material can make your home more aesthetically pleasing. After deciding on those, consider your window boxes’ length. 

Since many traditional-style uPVC windows are around three feet long, almost every window box style is available in 30-inch and 36-inch lengths. Window boxes generally look best if they are the same width as your window, but there are exceptions to the rule. For instance, you may want to get window boxes to run under, near, or slightly inside shutters or wide exterior trim pieces if you have them at home.

Make sure that the window box on your deck, porch railing, timber window cill, flat window cill, or box window cill fills the space while keeping the railing usable. To do this, leave several inches between the end of the window box and any steps to keep your space safe despite the presence of growing plants. Consider using a cardboard cut-out or chalk outline to visualise better the perfect window box for your area if you’re unsure of the right size.

How Do I Determine the Right Depth and Width for My Window Box?

Measure the height of your windows first before choosing your window box’s size. A box that is 20-25 per cent your window’s height can look rather large on your home, so consider their visual impact if you decide to get huge brackets for your flower boxes.

Bigger boxes are a practical option because they hold more soil, which means they won’t dry out as quickly and allow you to plant less drought-tolerant plants. If you live in a hot climate area, use a large window box. It’s also advisable to use deep flower boxes for perennial plants since these plants tend to root more deeply than annuals.


Window boxes can complete your entire exterior design and make heads turn on the block every time they pass by your home. When adding them to your house, make sure to settle on the right size for your windows by keeping in mind the details in this guide. Consider getting a custom-made one from a reliable supplier like us to ensure your window box’s quality and size.

We are an online trading arm of Brooks Bros (UK) Ltd., and we offer made-to-measure timber in Essex and London. Order wood for your window boxes today!