Spend enough time around custom built-in storage and you start seeing the same mistakes show up in every second project. Most of them aren’t dramatic — they’re the kind of small decisions that compound into something annoying you can’t fix without ripping out a wall.

The biggest one is overspecifying drawer height. People love deep drawers when they see them in a showroom. In their actual kitchen, a deep drawer fills with chaos in three weeks because nothing has a defined home. The right answer is usually two shallow drawers stacked instead of one deep one — the storage volume is similar, the visual line is the same, and you can actually find a whisk.

Hinge choice is another quiet killer. Cheap soft-close hinges feel fine for a year, then start hesitating, then stop catching, then need replacing. On a wardrobe with 14 doors that’s a slow march of small disappointments. The premium brands cost roughly twice as much per hinge and last roughly four times as long. The economics of going premium are obvious in retrospect. They are almost never obvious at quote time.

The walk-in wardrobe trap

Custom walk-in wardrobes are where I see the most expensive mistakes. The pattern is always the same: clients spend their budget on the visible elements — drawer fronts, hanging rails, lighting — and underspend on what’s behind them. The carcasses are thinner ply than they should be. The internal supports are spaced too far apart. The hanging rail is screwed into 12mm board with no nogging behind it.

It looks great on day one. By year three, drawers have started to bow under the weight of folded jeans, hanging rails sag in the middle, and the door alignments have crept out of true. Fixing it requires pulling the whole thing apart.

The fix isn’t dramatic. It’s specifying 18mm carcass material as a minimum, hanging rails on doubled-up internal supports, and drawers rated for the load you’ll actually put in them. Real cost increase: maybe 15 per cent. Lifespan increase: roughly double.

Lighting is almost always wrong

Internal cabinet lighting is the design decision that gets the least attention and produces the most regret. Three patterns I see repeatedly:

Strip LEDs run the full length of a shelf, mounted directly under the shelf above. They blast light into your eyes when you reach for something and shine straight down onto the front edge of whatever’s stored. The light you actually want is washed across the back of the cabinet so you can see what’s there. That requires recessing the strip into the shelf above or mounting it forward of the shelf line — small changes that get cut from the spec when budgets tighten.

Motion-sensor switching sounds great until you live with it. Quick movements in front of an open cabinet set it off; slow movements while you’re actually looking for something don’t. The reliable approach is door-trigger switching, which has been standard for years but somehow keeps getting omitted from current builds.

Colour temperature inconsistency between cabinet lighting and ambient room lighting is a small thing that drives people quietly mad. Specifying cabinets at 2700K and the kitchen pendants at 4000K means everything stored looks slightly off when you open the door.

What good design actually looks like

The good built-in storage I see in 2026 has three things in common. The carcass quality is over-engineered for the visible result — it doesn’t look special, it just stays right. The hardware is mid-to-premium tier, not entry level. The lighting is thought through as a system, not added at the end.

None of that is exciting. None of it makes for a striking before-and-after photo. All of it is the difference between a built-in that works in 10 years and one that needs replacing in five.

If you’re commissioning custom storage right now, the conversation worth having with your designer is about the unglamorous specifications. The visible parts will sort themselves out.