When considering how much of a gap should be under a fence or gate, a good rule of thumb is to keep gaps between 2 and 5 inches tall. This allows for some ground clearance for the gate but still provides safety for children and pets, who shouldn’t be able to squeeze through a gap of that size.

Since wood is weaker when installed horizontally versus vertically, a horizontal fence is prone to sagging. You can prevent this drooping from happening by building a sturdier fence. Use softwoods that are more stable, such as cedar and redwood, or denser hardwoods for your fence materials. If you can’t afford these pricey materials, use thicker two-by-six pressure-treated pine boards or shorten the span the fence boards have to cover by installing more posts.

Retaining walls offer more value to a home if they also divert water, prevent erosion, or help support a foundation. The ROI of a retaining wall is between 100% and 200%.

Both fences and walls can increase your home’s value, but you’ll spend significantly more on a wall than you would on a fence. A stone wall costs approximately $5,000, a retaining wall costs $6,100, and a fence costs $3,200 on average to put prices in perspective. 

Who pays for a new fence between neighbors depends on its location relative to the property line. If you build the fence entirely on your property, you are solely responsible for the costs of installation, maintenance, and repair. If the fence is built directly on the property line, both neighbors are typically responsible for the costs. In this case, it is essential to consult with your neighbor beforehand to agree on a plan for payment. While you should always inform your neighbor of your plans in advance, you generally cannot force them to contribute financially unless there are specific local laws, such as in California, where both parties might be responsible for costs unless a different agreement exists. It's a good idea to get a property line survey to know the exact boundaries before building.