If you're planning on having overhead cupboards in your laundry, ensure you add a bulkhead to remove the space between the top of your cupboards and the ceiling. Having your bulkhead installed during the build will be much cheaper than adding it after construction; bulkheads are usually not an expensive upgrade.
External laundry sliding doors are used to save space inside the laundry, however the maximum opening widths are often very narrow. Consider increasing the width of this door or installing an inward opening hinged door to make exiting the laundry with a basket of washing much easier.
Some builders only provide a freestanding laundry trough and cabinet as standard. Consider upgrading to a laminate or Caesarstone® bench with a drop-in sink as this will look tidier and provide space for extra cupboards and storage. If you're planning to run your laundry bench over a front loading washer and dryer, ensure the bench is high enough for the appliances to fit underneath.
Having a floor waste point in the laundry could save you in the event of a washing machine malfunction or water hose leak. Damage from laundry leaks often isn't restricted to the laundry but can run off onto carpets and floorboards throughout the rest of your home. If the waste point location is visible, consider having a tile insert drain cover installed.
Most standard laundry splashbacks consist of a few rows of basic tiles. Upgrading to a glass splashback will provide many different colour options and give your laundry a more modern feel. If you choose a glass splashback, keep in mind that all power points and other wall service points will need to be specified as the glass can only be cut before it's installed.