Click Mesh Sizing from the Setup tab:
Questions about applying settings?
Apply Automatic mesh sizing in ONE of the following ways:
Hide the Air part.
Select the house on the left.
To modify the mesh sizing, do ONE of the following:
Slide the Size Adjustment slider to 0.3.
Click Apply changes.
Select the house on the right.
Slide the Size Adjustment slider to 0.6.
Click Apply changes.
Click Spread Changes.