Wish the whole film was filmed outdoors

Would you want to be outside with them in the dark woods, knowing they will pick you off one by one at every turn and move? I would be in a house and board it up to protect myself, shelter...you know? You wouldn't want to be outside with zombies, now would you? I wouldn't.

Filming outside in the woods is cheaper, not expensive. So if they were running out of money, they wouldn't have spent money decorating a house with furniture they destroyed, or family photos and all that *beep*

If they had filmed outside, all they needed to worry about was the lighting.

the movie is about half an hour shorter if they stay out in the woods.

Or it screamed "these people are soldiers and are trained to set up in a good defensive location when they're outnumbered and surrounded in terrain favorable to the enemy". Or even just "these are adult humans with basic intelligence and common sense who know better than to try fighting in the woods at night against werewolves that have already killed well-trained and well-armed soldiers". What dumbass would stay out in the woods fighting werewolves when there's a perfectly good house to use as a fortress? They wouldn't have stood a chance in hell outdoors.