Storage unit construction: types, materials and what to look out for

You are looking for a storage unit and the listings give you nothing but shorthand: brick, modular, mesh, with no explanation of what that actually means for you as a user.

And the difference is considerable: one type will air out a bike and a set of tyres just fine, in another those same tyres start growing mould within six months.

Below you will find every construction type you will realistically come across in one place, with the details that help you pick the right one or judge the one you already have.

What types of storage unit construction are there?

Brick and concrete

The oldest and heaviest variant: solid walls of brick or blocks, sometimes with reinforced concrete ceilings. The best insulation and the strongest sense of privacy, but the weakest ventilation - without extra vents, damp and a musty smell are the norm here.

Modular steel: slatted, picket and mesh

The most common type in new buildings, based on hot dip galvanised profiles. It comes in three main variants:

• Slatted system - slats spaced about 35 mm apart, a good balance between airflow and privacy.
• Overlapping picket system - wooden or steel pickets overlapping each other, ventilated through openings at floor and ceiling level.
• Mesh system - steel mesh with a typical 100 × 100 mm aperture, the best ventilation of them all, but zero visual privacy, because the entire contents are on show.

Plasterboard

A less common type, used mainly in segments that do not demand high moisture resistance. Light and quick to install, but the weakest in terms of durability and resistance to mechanical damage.

Which one to choose? Ventilation, cost and durability compared

The values are indicative and depend on the specific system, the installer and the condition of the building.

If you keep a bike, tyres, sports equipment or anything else sensitive to damp in the unit, a mesh or slatted system is a better choice than a brick unit with no ventilation. If privacy and keeping things out of the neighbours' sight is the priority, for example because you store something valuable, brick or plasterboard will serve you better, provided you add ventilation.

Association consent and fire regulations when installing

Installing or replacing a unit's construction is usually not a decision you take on your own, even for a unit you own with its own land register. In practice you need the consent of the building manager or the homeowners association, and the materials used in basement corridors, which are often treated as escape routes, are subject to fire regulations.

I am not quoting specific fire resistance classes here, because they depend on the particular building and its classification. This is exactly the moment to ask the manager or a fire safety expert before buying a system, not after fitting it.

How to spot the construction type in a listing and why it matters

When browsing offers for rent or sale, check whether the advertiser gave the construction type at all. Its absence is often a sign that the seller or landlord either does not know or does not want to show a photo of the interior.

A well written listing should state the type outright, meaning brick, modular or plasterboard, and include a photo of the door and the interior, not just a plan of the estate.

If you are the one publishing the listing, this single piece of information genuinely shortens the time to the first enquiry, because it filters out people the type will not suit. The publishing rules are described on the how to add a listing page, and what belongs in the contract itself we covered in the article on the storage unit rental contract.