Home extensions are generally carried out to add more functional space to existing houses. The traditional way of creating more living space in existing homes has been to extend upwards or outwards. However, there is another option that not so many homeowners are aware of — the 'house raise and build under' approach. This approach involves raising a house and then building under it, as the name clearly suggests. If you are considering extending your existing house, here are a number of typical circumstances when raising the house to get the extra living space you need might be a smart approach.