For many homeowners, an understairs cupboard is the ideal storage solution. They’re discreet, compact, and easy to hide away if you don’t want to show them off. Understairs cupboards may be most beneficial for storing items you only access occasionally. Still, if you don’t ventilate them well enough, they may also become places where mold and mildew develop in the long term.
You can ventilate the understairs cupboard in several ways per your needs. If you have an outside wall available at the back of your cupboard, try installing an air vent or an exhaust fan for letting out the humid air. If you don’t have outside wall access, putting vent grille or making cuts in the cupboard door panels might be an option. You can also swap the wooden doors of the cupboard with grilled panels.
In this article, I will discuss ways to ventilate understairs cupboards properly, so mold and mildew don’t form in the first place.
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Why Ventilating Your Understairs Cupboard is Important
If you have stairs in your home, the chances are that there’s a cupboard under them. If this cupboard isn’t adequately ventilated, it can lead to all sorts of problems due to humidity and trapped moisture. Ventilating these spaces can help you in many ways.

Getting rid of the smell
In understairs spaces, we often store things we don’t want anywhere near our bedrooms, such as pet supplies or cleaning products. Make sure the understairs cupboard is correctly ventilated if you want to keep unpleasant smells at bay.
Preventing mold growth
Mold grows best in poorly ventilated and damp areas. So while you might not be able to see it in your understairs cupboard, it’s likely that you can smell it. Ventilating the understairs cupboard would prevent mold formation and protect your things stored in that space.
Avoiding damage to your property
If your understairs cupboard isn’t well-ventilated, it will get hot and stuffy. When that happens, moisture condenses on windows and walls. That’s a breeding ground for mold. If you have wooden floors or cabinets in your cupboard, they may warp due to humidity. Ventilating the cupboard avoids this damage.
How to ventilate a cupboard under the stairs (Best options)
Fortunately, adding proper ventilation to the understairs cupboards doesn’t take much time or money. It is one of the most affordable and convenient DIY projects you can do for your home!
Put an air vent in the outside wall
Install an air vent in the outer wall that generally sits at the back of your understairs storage space to ventilate properly. Ensure that the air vent is installed high up with a hood over it so the hot air can escape outside. You can even install an air vent on the lower side of the wall that will let the cold air in. Also, you can assist the vent with a fan that runs when the humidity level reaches a certain point.
Install an exhaust fan inside the cupboard
If there is access to the outer wall through this understairs space, insulate the wall with Styrofoam sheets to prevent moisture from outside. Install a ‘through the wall fan’ on an appropriate place and a small heating grill opposite the fan. The fan will ventilate the cupboard space while adding heat from the grill.
Make some cut out vent holes in cupboards doors
Many cupboards and storage areas are located beneath stairs without access to an exterior wall. In that case, cut some holes in the cupboard doors to facilitate ventilation. It’s pretty easy to cut holes in your cupboard’s door panels, and you also can make the holes look aesthetically pleasing. Don’t go over the top, as a few holes or cuts will be enough.
Install vent units on cupboard doors
If your understairs cupboards provide you with abundant storage but not enough air circulation, try installing one or two small vent units or vent grilles on each door. These vent units are beneficial in reducing mold and dampness in poorly ventilated areas. These are readily available in your local hardware stores in different shapes, sizes, and materials. Round and rectangular are the most popular styles.
Switch to grilled cupboard doors
While they may look nice, solid wood cupboard doors can get very stuffy and poorly ventilated, trapping humidity and heat in an enclosed space. If you’re looking for ways to ventilate your understairs cupboard, consider replacing your cupboard doors with custom-sized wooden grilled panels. It helps circulate air efficiently while giving your cupboard an upgraded look.
How to ventilate under stairs toilet
In many homes, the homeowners prefer to have an understairs toilet instead of building a cupboard. Ventilating a toilet is of utmost importance as the building regulations require that every bathroom needs to have a window or ventilation. Keeping the regulations aside, if you plan to install an understairs toilet, you need to ensure proper ventilation in place so that it doesn’t get too stinky! Here are some ways how to do that:
Install an exhaust fan
Because understairs toilets are small, ventilating them is even more critical than venting toilets elsewhere in your home. They can smell horrible if they aren’t properly vented, so make sure you choose the most efficient way of ventilation.
If you have exterior wall access in the toilet, installing an exhaust fan is the best and most effective way to ventilate a windowless understairs toilet. Exhaust fans not only get rid of the moisture but also take care of the toilet odors, although installing an exhaust fan can be a bit more expensive than the other ventilation methods.
Install a recirculating fan
You don’t need access to an exterior wall for installing a recirculating fan for ventilation. A recirculating fan doesn’t throw stale toilet air into the exterior. Instead, it lets the toilet air pass through a filter medium to remove odors. The understairs toilets don’t have a bathtub or shower, so the moisture level isn’t high. A circulating fan is a perfect workable option for half-baths.
Final thoughts
Fresh air is one of those little things that can make a huge difference in how your understairs cupboard or toilet feels. Understairs cupboards and toilets can benefit significantly if a proper ventilation system is installed. Adequate ventilation prevents these spaces from being stuffy and retaining moisture. As a result of efficient ventilation, mold formation can be prevented, which will keep your belongings in the cupboard safe, and keep your toilet smelling fresh!