Use Auto-Bracketing on your Camera for High-Light Situations
The Problem: Over-exposed (blown-out) windows when the interior is properly exposed.
Two flashes and faster shutter are not enough to properly expose outside the windows (Ex: see the foliage). OR The sun is hitting your lens outside, making the front of the house improperly exposed for both the sky and the house. Instead of trying to get one poorly exposed shot, use bracketing to get three (3) different exposures (Normal, Dark and Bright) and blend them together in post-shoot editing.
How to get bracketed shots during the shoot:
If you use Lightroom for your editing and blending, this is a great video with helpful tips: