There are plenty of helpful frameworks and grids on the Web that aid designers and developers who are looking to start a website but don’t want to start from scratch. Bootstrap, HTML5 Boilerplate, and 960 Grid are examples of foundation CSS, HTML, and JavaScript that can help you kick-start a site design.

However, grids and frameworks come at a cost. Because they are designed to cover a large number of generic use cases, they will include plenty of things that you don’t need on your site. This extraneous content can be a hindrance to your page load time rather than an aid to your development time; if you’re not careful about how much is included as you start implementing a grid or framework, you could have a lot of unnecessary assets, markup, or styles loaded on your site.

Lara Callender Hogan.