Here are four answers to that question:
So it is right first time
The design process is based on fulfilling your needs within your budget. It is focused on creating better results for the future, not just on resolving problems for short term gain. Our homes are for shelter, privacy and security; they should be durable as well as sustainable.
To make the most of your land
Proper siting and orientation will optimise daylighting, providing warmth and light when you need it, and avoiding heat and glare when you don’t, as well as sheltering you from wind and rain. The right layout will optimise views while avoiding overlooking from neighbours. 
To save money
As your architect we will provide a design solution that will save you money: an efficient use of space that will also be energy efficient, using advanced ventilation, cooling and heating systems, with the most economical insulation techniques. It will be sustainable too.
To know you are safe
A building project can be a daunting undertaking – the demands of councils and builders can turn your dream into a nightmare. It helps you to have the right architect watching out for you every step of the way.