How to build a radiator window bench

Our vintage Colonial home features a lot of radiators… and not the beautiful Victorian kind. These radiators require covers to look even halfway decent, so my go-to move has been to turn an awkwardly placed radiator into a window bench at every chance.

The first time we did this, we created a massive window bench in our sunroom that is the perfect napping spot.

And we DIY-ed that French Mattress.

The next time, we opted to add a window bench to our walk in closet, that is the perfect spot for reading, folded laundry, and seating for seasonal closet purges. Today, I’m going to walk you through how we built this bench.

When you don’t have the space for a window bench, here are more chic ideas for radiators.

For all the details on our master closet, head here.

Let’s get started.

We started with an ugly radiator…

Step One: Frame out the bench

First off, you need to decide on the footprint on your bench and cut 2×4’s to frame out the base. This bench is a slightly unusual shape, but the approach is still the same regardless.

Once you’ve created the base build upwards into rectangles to create the front frame of the base. Once the rectangles have been built, you can nail them directly into the floor using nails that are long enough to go through the flooring material and the subfloor for strength. Take care to consider the size of the vents you’re planning on for the finished bench, so that your vertical supports don’t interfere.

As for height, I’ve always found that a finished height of ~19 inches off the floor is ideal for a window bench. So, consider the height of your cushion (2-3 inches) plus the wood on the top of the bench (3/4 of an inch), meaning your vertical supports should be ~16″ tall.

On the back wall, get a very straight piece of wood and nail it directly into the studs in the wall, level to the front frame of the bench.

Then, cut 2×4’s to attach the front frame to the wood mounted on the wall. This is where the strength and support comes from. We used our handy Kreg Pocket Jig to sink the screws for the side supports into the front frame and back support.

Step Two: Drywall

Since your bench is touching adjacent walls, we’ve always found drywall to be the most seamless and cost-effective choice for wrapping the frame of the bench. Cut down pieces of drywall to fit the size of the frame and attach them using drywall screws. If you have spare drywall lying around, this is a good project to use it up.

Then, you’re going to want to apply a thin coat of drywall spackle over drywall tape if your bench has a corner, as ours does. Then sand, then spackle, and sand again.

Step Three: Trim it out

The easiest way to make a window bench feel intentional is to continue the baseboards from the rest of the room across its face. We used Metrie Fashion Forward baseboards in this space.

Then, you’re going to want to cut out the holes for the metal vents, which will allow the hot air to escape. Make sure to consider the width of the trim you’re going to be using around the vent opening in where you plan out the location of the vents.

Then, you’re going to want to cut out the mesh inserts (we used this one from Home Depot) to be slightly larger than the vent holes. You attach them on the backside using a staple gun, taking care to keep the pattern straight.

Finally, you add picture frame moulding as a frame around the metal screens using glue and/or finish nails. Then, caulk everything.

Step Four: Cut the top

You’re nearly there! Using 3/4″ high-grade plywood, cut a top for the bench that will rest on the back ledge, the side ledge, and the front of the frame. Don’t go less than 3/4″ thickness, because you risk it bending when someone sits on it. Make sure to give it a good sanding, and attach a piece of wood on the lower front side that will keep it from sliding off the bench by engaging against the front of the frame.

Step Five: Paint it

Now, you’re ready for the most transformational stage: paint! First, give it two coats of primer (fresh drywall sucks up paint like a sponge). Then paint the bench to match the walls, it’s easiest to paint the top separately. Allow the paint to properly cure.

Step Six: Add insulation

This step is optional, but we’ve found it to be very helpful for keeping the heat from rising directly into the bench. Using flexible thermal insulation we created a tunnel over the radiator for the heat to escape through the vents on the front of the bench. Once the top went back on the bench and there wasn’t light shining through the vents, the insulation became invisible.

And that’s it, a cozy bench that hides an eyesore of a radiator (win-win!).

6 thoughts on “How to build a radiator window bench

  1. You seem to have set this up as a permanent fixture. What is your plan should the radiator need service? Is the top easy to open?

  2. Thank you for this! Our home has long radiators under big windows and I would love to have a window seat – now I finally know how to do it! Thank you!

  3. This is exactly what we’re wanting to do in our kitchen over our hydronic heat but concerned about it heating just the bench, as you mention in step 6. Can you provide pictures or explain a bit further how you did this last step? Do you find your radiator is still able to heat the area as always having used the insulation?

  4. Hi there!
    I’ve got electric baseboard heaters, and would love to do this – but am concerned about fire safety and insurance. Do you live in a cold climate where you really have to crank the heat? We use our heaters a lot in winter here in Canada. I see you did step 6 – does that keep all of the heat off the wood? I’d hate for it to cause a fire and be blamed for placing a combustible on top of a radiator 🙂 Thanks for your help!

    1. Hi Sheila, our baseboards are hydronic and don’t get very hot. We checked with our contractor and he wasn’t worried about it, but I’m not sure if electric is different? We previously had wood covers over our radiators anyway, so it isn’t really any different from what was here before. Not sure if that helps!

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