Easy DIY Farmhouse Interior Window Trim

Install your own rustic DIY window trim with this simple step by step tutorial.

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Fixing up the old wood windows in our house is one of my favorite parts of every room makeover. So far, I’ve done it in the kitchen, living room, our son’s bedroom, and our daughter’s nursery. I start by restoring the wood frame and then finish it off with new trim. It brightens the room and makes everything look fresh and new! Head on over to this post if you want to give your window frames a nice update, or continue reading if you’re just looking to put up new trim!
There are endless styles and options for interior window trim, but I kept things as simple as possible – just grab a few 1×4 pine boards and you’re good to go.

Tools & Supplies:

• Orbital Sander
• Stain of your choice
• Polyurethane of your choice
• Level
• Finish Nailer
• 2 1/2″ Finish Nails
• Clear Paintable Caulk
• Caulk Gun

Step 1.

Remove the old window trim.

I wrote a separate post about removing trim without damaging drywall, but you just use a taping knife to guard the drywall while you pry the trim off with a small pry bar.

Step 2.

Measure the window and cut four 1x4s to size.

When you measure, leave 1/4″ around the entire window frame. This is called the “reveal”.

I cut the vertical trim to the full height of the window + 1/2″ (1/4″ reveal at the top and bottom). I cut the horizontal trim to the full width of the window + 3 1/2″ + 3 1/2″ (both vertical pieces of trim) + 1/2″ (1/4″ reveal on each side).

Step 3.

Sand and stain the boards. I used Varathane’s aged wood accelerator in brown and sealed them with semi-gloss polycrylic.

Step 4.

Once the boards dry completely, attach them around the window with 2 1/2″ finish nails. Make sure the finish nails hit the studs around the window frame.

Start with the vertical boards and then attach the top and bottom boards.

It’s common to cut trim at 45 degree miters for the corners. However, I wanted a more rustic look, so I decided to cut everything at 90 degrees and stack the trim at the joints. It’s just personal preference!

Step 5.

Last, but not least, seal around the new trim with clear paintable window caulk. Seal both the inside and outside edges.

Add a new curtain rod and curtains, and there you have it!

It’s not as bold as many of the common farmhouse interior window trim styles, but I’m really happy with how it looks in our house – simple and rustic.

Here it is in our sons room:

BEFORE

AFTER

And our daughter’s room:

BEFORE

AFTER

Please let me know if you have any questions and I’ll get back to you as soon as possible!

You can find all the details for the bedrooms here:

• Boy Woodland Bedroom Renovation
• Baby Girls Soft Pink Nursery

| Tylynn |

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