The short and sweet answer to this question is ‘yes’, your web design can definitely affect your rankings. In order to be sure that any major web design you implement does not adversely impact your search engine rankings, you should test a new website for some or all of the factors described below.
Identifying thin pages
Web design renovations can accidentally introduce pages that are very thin on content, and would, therefore, have very little value to readers. Use an SEO audit tool to spider your web pages, so that you can identify any which have minimal content.
404 ‘Page Not Found’ messages
You can use a website crawler to discover any 404 response codes which are issued by the server when something unexpected occurs. These response codes always indicate that something’s gone wrong, generally that a page is missing or has been incorrectly spelled in the URL.
Crawl the new website
There are a number of crawlers you can use to crawl your new website by providing it with a list of URLs. By crawling the original site map, you will be able to compare it to the new one and find any issues on the new site. Check out the number of 301 redirects, making sure that you have a one-to-one ratio on redirects.
Scan for internal links that are broken
You should always run a diagnostic test to check for internal links that have been broken, and even though it won’t tell you what’s wrong, it will tell you that something is wrong. Once you know where to look, it should be a fairly simple matter to find what caused the broken link and repair it.
Maintain site architecture
One of the most important aspects of maintaining your high rankings is to ensure that your site architecture is still well-organized and logical. If your site originally had poor site architecture, it would be a good idea to upgrade during your web redesign, but make sure the revised site architecture is very well organized.
Stage the website
This is a very handy technique for testing your revised website for any kind of problem. All you have to do is create an exact copy of the new website, and put it in either a new folder or on an altogether different server. Make sure that the new site is blocked to search engines before doing all the testing you want to do, and fixing any errors which crop up.