Have you ever wondered: ‘How much does a Second Storey Addition Cost?’ and ‘Should I extend out or build up? Which will cost more?’ Adding a second storey does not always cost more than a home extension. Sometimes it actually makes more sense to add another level, but homeowners can be put off by thinking that this costs more than a ground floor home extension. This is not necessarily the case! This article reveals the inside scoop on whether building a ground floor extension or adding a second story on your house would be best for you.