[This is part of Our Kitchen Molding Makeover series]

window valance box made from mdf moldings

Each of my designs gets its own pattern number. This is VALANCE BOX-101

Video 1: Coming up With the Design

On This Page

  • Molding and Applique Inventory
  • How to Build the Valance Box Step by Step
  • How to Prep and Paint
  • How to Install on the Window


Molding Inventory to Make the Valance Box $14.54

We can make two small window valance boxes with the material we bought, so I divided the total material cost in half to come up with this total.


You can use any number of small crown molding profiles for the valance box cornice.

More about CM-005 here >>

crown molding small pine material lowes

$1.50/lf (4′) = $5.98


After trimming it down to the right width, I used a piece of scrap from this flat-stock to make the soffit.

More about FS-002 here >>


pre-primed mdf flat-stock board for plinth blocks

$0.92 (4′) = $3.68


This ogee baseboard molding is the perfect size for the delicate proportions I wanted on this valance box.

More about PM-008 here >>

mdf baseboard molding pre-primed ogee

$0.60/lf (4′) = $2.40


Even though this fir is a soft, somewhat fragile material to work with, it’s inexpensive and available at Lowes whenever I need it.

More about PM-001 here >>

panel trim molding from lowes home improvement

$0.62 (4′) = $2.48

Special Order: Ornate Woodworking Applique

I’ve had this applique for several years, a left-over from previous projects.  It’s from Decorators Supply and is called a drop.  The minimum order size for Decorators Supply is $125.00.  So you’ll have to find some other places to apply ornate details in your home so you have enough for a minimum order.  It’s easier than you think!

See our growing list of the architectural ornaments we use here >>


woodworking applique onlay floral

The real fun comes when we figure out how we want to paint the frieze and applique.

[See all of the moldings we use on The Joy of Moldings at our Molding Inventory page]

How to Build the Valance Box Step by Step

Step 1: Create a Model

All this valance box has to do is mostly hide the ugly mechanism to our current window blinds, so it doesn’t need to be very big.  But it must be graceful and somewhat delicate to match the resolution of the appliques.  These moldings should do just fine.

Limiting Factors  The right side of the window is very close to the cabinets, so the box has to fit that space without looking cramped.  We eventually want to install crown on the kitchen cabinets, so the valance box can’t limit that either.

woodworking ornaments on valance box model

Here I’m playing with the proportions of the fireze.

Step 2: Build the Box

diy window cornice valance box mdf materials

Trimming the mdf flat-stock down to size on my table saw.

diy window valance box how to build

A 45 degree outside miter on both ends.

diy window valance cornice box mdf material

Make these to whatever depth you want your own valance box to be.

diy window valance box made from mdf material

Use 23 gauge micro pins for a nice finish.

diy window valance box made from mdf material

Video 2: How to Build the Box


Step 3: Install the Necking Molding

diy valance box molding installation

Scribe like this for perfect miter marks each and every time.

diy mdf valance box necking molding

This little jig keeps the molding from chattering during the cut.

About the Jig

I make these little jigs out of scrap flat-stock.  They help keep these small pieces of molding from vibrating when being cut.  The vibrations can cause the molding to split, which is not good.

diy mdf valance box materials

Always test the fit of your molding before gluing and nailing in place.

diy mdf cornice molding for valance box

The necking fits so now I’ll glue and nail it in place.

Video 3: How to Install the Necking Molding

Step 4: Install the Cornice Soffit

A soffit is not absolutely necessary, I could have simply wrapped the crown around the top of the valance box and be done with it.  But I’m always wanting to add a touch more detail to things.

diy molding window valance box made of mdf

The soffit will be a nice touch to the design, and so is worth the extra work.

diy molding projects from mdf material

I’ll wrap the small crown molding around this soffit.

 Above  I’ll be attaching L-brackets to the soffit when it comes time to mount the valance box on the window, so the soffit has more than just a decorative function.

Video 4: How to Install the Flat-Stock Soffit

Step 5: Install the Crown Molding

diy valance box from mdf material

diy window valance box made from mdf board

mdf board molding projects

Video 5: Cutting and Wrapping the Crown Molding

Step 6: Fill Nail Holes With Spackling

Sand the filled nail holes flush when the spackling is dry.

diy mdf molding projects free

Step 7: Prime the Valance Box

Use a sandable primer for bare wood and not Kilz.  See our Consumables page for details.

how to prime a diy mdf valance box

Step 7: Sand the Whole Thing

Sand the whole valance box perfectly smooth when the primer is totally dry.

primed window valance box

Step 8: Install the Ornate Applique

Most woodworking appliques/onlays come with imperfections from the mold that you have to clean up before installing.

wood applique onlay

I use a file, detail knife and sandpaper when prepping appliques.


how to install woodworking appliques


install woodworking applique from decoratos supply

 Step 9: Prime

Use a sandable primer like the one listed on our Consumables page.  Do not use primer like Kilz 2.

window valance box made mdf

Step 10: Sand With Fine Grit

Use a fine grit sand paper at this step.  If you find a spot that needs heavy sanding or filling, then sand down to bare material if you need to, just be sure to re-prime when you are finished.

how to sand a valance box

Step 11: Paint

Apply two finish coats of paint.  Use the maximum amount of paint extender like Floetrol or X-I-M when painting architectural details like this, it will help level the paint as it drys leaving fewer brush strokes in the paint.  This is especially important when painting friezes with ornate onlays like this.

Benjamin Moore paint for moldings

We are using Benjamin Moore Aura paint with a satin finish for our kitchen moldings.  The color is called White Dove number  OC-17.

paint drying on diy window valance box

If Jennifer keeps making me such delicious snacks while I’m working in the kitchen, I may find all kinds of reasons to never finish it!

Step 11: Install Mounting Hardware and Valance Box

I used a couple of L-brackets to hang this valance box, but there are lots of other ways to do it — use whatever method you’re comfortable with.

window valance box mounting hardware

I bought a box of 4 ea. L-brackets for about $3.00 at my corner ACE Hardware.

how to install mount a diy window valance box

how to mount a diy window valance cornice box

how to mount a diy window valance box

diy window valance box with ornate applique

That’s all there is to building your own window valance box!

If you want to learn about more moldings see our How to Install Moldings Series.

[This is part of Our Kitchen Molding Makeover series]