Garden Storage Unit: Box, Cabinet or Shed? What Fits What

A garden storage unit is anything from a lidded box for cushions to a full-size shed for bikes and a lawnmower, and the most common mistake is buying the type before working out what needs to go in it. A deck box will not keep a mower dry, a tall cabinet will not take a bike, and a shed is overkill for a few bags of compost. This page starts with what you are storing, then compares the four main types of unit, the three materials, sizing, the base, security, and the planning rules that apply once a unit gets tall or sits near a fence.

Start with what you are storing

Match the unit to the bulkiest and most valuable things you need to keep, not the smallest.

Seat cushions, covers and toys: a lidded storage box or bench. Our guide to garden cushion storage boxes covers keeping fabric dry.
Hand tools, pots, feed and sprays: a tall storage cabinet with shelves. See garden storage cabinets.
Wheelie bins and recycling: a low bin store with a lifting lid. See garden bin storage.
Bikes: a dedicated bike store or a shed with a wide door and a ground anchor. See bike sheds for the garden.
Lawnmower, strimmer, ladders and garden furniture over winter: a shed, or a large metal or plastic store with double doors.
Logs: an open-fronted log store, because firewood needs airflow, not a sealed box.

If the list covers several rows, one shed with shelving and hooks inside often beats three separate units, and it takes up less of the garden. Our shed storage ideas show how to fit it out.

The four main types of garden storage unit

Storage boxes and benches

Low, lidded and easy to place on a patio or deck. Benches double as seating. They suit light, bulky things such as cushions and toys. Even a box sold as waterproof can let in condensation, so keep fabrics in breathable bags inside. More in our guides to storage benches and waterproof storage boxes.

Tall cabinets

Upright units with shelves, usually around head height, that stand against a house wall or fence. They take very little ground space and keep tools at eye level. They are rarely deep enough for a mower or wide enough for a bike.

Low sheds and lean-to stores

Low-roofed units, often with a sloping lid and front doors, built to sit under a window or along a boundary. Bin stores and many bike stores fall into this group. They hold more than a box but stay below fence height, which matters for planning (see below).

Sheds

Walk-in buildings with a door, a floor and space for shelves. A shed is the only option that handles a mix of long, heavy and awkward items, and the only one you can work inside. It needs a proper base and takes more of the garden.

Wood, metal or plastic?

Each material solves one problem and creates another.

Galvanised metal garden shed with double doors under a climbing vine — A galvanised metal shed with double doors on a lawn. | Traditional Metal Shed by TheFearow (Public domain), via Wikimedia Commons, https://commons.wikimedia.org/wiki/File:Traditional_Metal_Shed.JPG

Wood looks natural, can be fixed to, shelved and painted, and breathes, which helps with condensation. It needs a treatment every few years and must be kept off wet ground. Pressure-treated timber lasts longer than dip-treated. See wooden garden storage.
Metal, usually galvanised steel, does not rot, is hard to break into and needs little upkeep. Its weakness is condensation: on cold nights moisture forms on the inside of the roof and drips onto whatever is stored. A timber or plastic floor, a vent and a breathable cover over tools all help. Metal stores are light for their size, so they must be fixed down against wind. See metal garden storage.
Plastic and resin units are low maintenance, do not rot or rust and wipe clean. Cheaper ones can bow in summer heat and become brittle after years of sun, and lightweight units need weighting or anchoring. See plastic garden sheds.

Sizing a garden storage unit

Most people buy one size too small. Before ordering:

Measure the largest item, including handles. A mower with its handle up, a bike with its pedals and bars, a folding table: note length, width and height.
Check the door opening, not just the internal size. A unit can be big enough inside while the door is too narrow to get a bike or mower through.
Allow working space. If you need to reach things at the back, leave room to step in or choose double doors.
Measure the site, leaving space to open doors and lids fully, and a gap behind for air and maintenance.
Think ahead. Children’s bikes get bigger, and garden furniture needs somewhere to go every winter.

The base: keep it level and off the soil

Almost every storage unit fails early when it sits straight on grass or soil. Damp wicks into wooden floors, metal frames rust at the bottom edge, and doors twist out of square on uneven ground, which also stops them locking.

For boxes and small cabinets, a few paving slabs bedded level are enough. For sheds and large stores, use a slab, a concrete base or a timber frame on adjustable supports, and lift any timber floor clear of the ground on pressure-treated bearers so air can move beneath it. Many metal and plastic units come with a floor kit or a recommended base; follow it, because the anchoring usually depends on it.

Security and insurance

Garden storage is an easy target, particularly when it holds bikes and power tools.

Use a solid hasp and staple with bolts or coach screws that cannot be undone from outside, and a good closed-shackle padlock.
Choose units with hinges that cannot be unscrewed from outside, or fit security screws.
For bikes and expensive kit, fit a ground or wall anchor and lock the item to it. Sold Secure tests and grades locks and anchors, and some insurers ask for its ratings.
Keep valuables out of sight; frosted or covered windows help.
Read your home insurance policy on outbuildings. Cover limits and lock requirements for sheds and garden storage vary between insurers.

Do you need planning permission for a garden storage unit?

Most garden storage in England falls under permitted development for houses, so no application is needed, as long as it stays within the limits. According to the Planning Portal:

No outbuilding on land in front of the wall forming the principal elevation of the house.
Single storey, with a maximum eaves height of 2.5 metres and a maximum overall height of 4 metres with a dual pitched roof, or 3 metres for any other roof.
A maximum height of 2.5 metres for any building, enclosure or container within 2 metres of a boundary.
No more than half the land around the original house covered by additions and other buildings.
On designated land (national parks, the Broads, AONBs, conservation areas and World Heritage Sites), buildings and containers at the side of the house need permission.
Within the curtilage of a listed building, any outbuilding needs planning permission.

Flats and maisonettes do not have these rights, and some estates have Article 4 Directions or planning conditions that remove them, so check with your council if you are unsure. Building regulations rarely apply to garden storage: a small detached building under 15 square metres with no sleeping accommodation is normally exempt. For the detail, see our page on planning permission for a garden shed.

Frequently asked questions

What is the best garden storage unit for bikes?

A dedicated bike store or a shed with a wide door, on a solid base, with a ground or wall anchor inside. Lock the bikes to the anchor as well as locking the door.

Do I need planning permission for a garden storage unit?

Usually not for a house in England, if it is behind the front of the house, single storey and no more than 2.5 metres high within 2 metres of a boundary. Listed buildings, flats and designated land have tighter rules.

How do I stop condensation in a metal storage unit?

Put it on a dry, level base with a floor, keep any vents clear, and avoid storing anything damp inside. Cover tools and fabrics with breathable covers, not plastic sheeting.

Can a garden storage unit go straight on grass?

It is best not to. Grass and soil hold moisture, rot timber floors, rust metal frames and let the unit move out of level. A few paving slabs or a simple timber frame makes a big difference.

What size storage unit do I need for a lawnmower?

Measure the mower with the handle in its storage position and add room to wheel it in and out. Check the door width as well as the internal floor size.

Are plastic garden storage units waterproof?

Most keep rain out well, but condensation can still form inside. Lift the contents off the floor and use breathable bags for cushions and fabrics.

Planning more than storage? Browse Best Garden Room for guides to sheds, garden rooms and offices.