SEO, when done right, never interferes with web design, but sometimes redesigning a site can unknowingly interfere with search engine optimization. This is why teamwork among SEOs, designers, marketers and developers is critical during a blog redesign process.
Here are 5 common web design mistakes that kill search engine optimization:
1. High-traffic pages are removed or deleted
The blog redesign process often identifies site content that is no longer a priority, but pages should never be deleted. Older blog posts often bring in a high volume of traffic, and those aged URLs create domain authority and page authority for organic search traffic. Instead of removing pages, protect your SEO and visitor experience by using 301 permanent redirects to ensure visitors via organic search and referral sources can still find relevant content.
2. Top-level keyword terms are omitted from new copy
Assuming you are following SEO best practices for copywriting, this won't be an issue. But too often the blog redesign process forgets to take into account previous keyword research, and text is altered without undergoing an SEO review. The top 3 essential SEO copywriting elements to review (and likely maintain through the blog redesign) are title tags, meta-descriptions, and on-page content like subheadings, bolded text and anchor text for links.
3. The new design does not leave enough room for copy
On January 19, 2012, Google announced a page layout algorithm improvement that looks at the web design layout and the amount of content above the fold. Blog redesigns that emphasize images and ads in the top half of the page mean valuable real estate for great copy is diminished, hence hurting your search engine optimization. Visitors who need to scroll down the page to see the content often decide to bounce, immediately returning to search results. This negative signal indicates to search engines that your content should be downgraded in the results. Avoid this by ensuring the web design allows for adequate room for copy in the top half of the page.
4. The beautiful design takes longer to load
A blog redesign might introduce Flash, a heavy image-based design, too many externally referenced files or extraneous code, all of which can slow down page load times and annoy users. Site performance and bounce rates due to slow load times should be monitored and fixed as needed. Webmaster tools for Google or Bing are useful tools for tracking site speed and page load times.
5. CMS changes affect URLs
Different programming languages and content management systems can affect the URL structure and file extensions used on the blog. These changes—in addition to folder structure changes, which are commonly introduced when categories are changed or removed—should be handled using 301 permanent redirects from the old URL to the new URL.
As you can see, it is easy to unintentionally introduce a blog redesign that negatively impacts search engine optimization. For this reason, it is highly recommended that you bring all partners to the table during the redesign process so that you can reap the benefits of a great web design while ensuring your search engine optimization remains stable or improves.
Considering search engine optimization factors during the blog redesign process should ultimately leave you less stressed at the site launch, and save you money – avoiding SEO problems is much easier than fixing them. Don't paint yourself into a corner by redesigning without SEO planning and keyword research.
About the Author
Monique Sherrett  is the owner of Boxcar Marketing, a Vancouver-based online marketing company that handles online marketing projects  related to blogging, content strategy, search marketing and web design. For free advice, follow the Boxcar Marketing blog or Twitter @boxcarmarketing . Or ask for a quote on your online marketing project by emailing monique at boxcarmarketing.com.