A Quiet Place: The Road Ahead

At the end of Act 3 (The Forest), you'll exit the house through the window on the first floor. After a short cinematic, a throwing mechanic is introduced. From this moment, you have 3:30 to leave the area.

There are plenty of bottles and bricks scattered around, so distracting the monster shouldn't be a problem. I found two planks in the garden: one behind the fence gate in front of you, and another in the shed to your left.

I strongly recommend ignoring the shed while going for this achievement. Here's the strategy:
1) Play on EASY.
2) Throw a brick to the left and go straight, then crawl under the countertop.
3) Pick up a brick and throw it at the shed's glass window.
4) Open the gate and grab the plank. Don't crouch when approaching the plank—you want the monster to enter the fenced area.
5) Leave the fenced area and head right, toward the shed.
6) Pass the wooden statue (bear), then another statue (?).
7) Slow down when you reach the puddle of water.
8) Place the plank over the gap and cross to the other side.
9) Climb both ledges.

If you fail to get the achievement, load a previous save with the "Empty House" label.

Here's a video solution if you prefer: