Ask any experienced builder what kills buildings and the answer is always the same: water. Get drainage right and almost everything else becomes a maintenance item. Get it wrong and nothing else you spend money on will save you.

How Water Destroys Buildings

Water rots timber, corrodes fixings, saturates insulation, and pushes against foundations. Worse, it freezes — and every freeze-thaw cycle levers cracks a little wider. Damage that took one wet winter to start can take a decade to fully reveal itself.

The Role of Proper Grading

The ground should fall away from the building on every side, roughly 150mm over the first two metres. Flat or reverse grading sends every storm straight at your foundation. This is the cheapest thing on this list and the one most often skipped.

Drainage Systems That Help

• Perimeter drains at footing level, laid in clean stone with a filter fabric.

• Gutters and downpipes discharged well clear of the foundation, never at its base.

• Surface channels or soakaways where hard landscaping traps run-off.

Don't Forget the Details

Most leaks happen at junctions, not in the middle of a surface. Flashing at roof-to-wall joints, window head details, and thresholds do the real work. Detail them properly and inspect them yearly — they are small, cheap, and decisive.

Drainage Pays for Itself

Good drainage typically adds a small percentage to a build cost and can double the life of the structure it protects. There is no other line item in construction with that return.