There are several ways to improve your NatHERS energy rating which are low-cost. To improve your NatHERS rating, for instance, to have a 6 star energy rating house, you need to:
- Add enough insulation to ceilings, walls and floors
- Mitigate thermal bridging using thermal breaks or air spaces
- Use appropriate openings (windows and doors) for cross ventilation and passive cooling
- Weather-seal all external windows and doors
- Have shading with high-projection over west-facing windows
- Install external adjustable shading devices over east and west facing windows
- Utilize thermal mass in the living areas to absorb heat from northern windows