I often use flash in my landscape photography. Here you can see one example that lights up the house. Remote triggering of flash is necessary and I can just highly recommend
Phottix remote triggers. Phottix never misfire and for the first time you feel that you can trust your equipment. Flash is used here in combination with long exposure meaning that you could trigger the flash in the beginning or in the end of the exposure. With a fixed object like a house... (compared to a person that I would trigger in the end to get a sharper picture). Check your camera to see what it is called for the different flash sync names.
If you do not have a trigger, do not worry as you can use a flash light or the flash in your hand and walk up to the house and pop the flash as long as you do not get light on yourself. With the flash light, you paint the object that you want to be brighter during the long exposure. This is ofcourse during low light or night photography.