• You already have a content management system (CMS) and a site designed with styles sheets and templates. This allows you to make design refreshes at a relatively low cost.
• Your site is five years old or less. Most sites in this range are relatively current in look and feel, as well as functionality.
• You need minimal functionality changes. If your site is relatively simple, it will last longer.
• No need for new navigation or layouts. Again, a simple site without dramatic changes in content or navigation can last longer.

When it makes sense to reinvest:

If any of the following apply, it's time to think about your options. If more than one apply, it's time to think seriously about your five-year web plan.

• You have a static, HTML website. Making changes to these sites often requires someone with HTML experience. Current technology empowers clients to do a lot themselves effectively and affordably.
• Site is more than five years old. There have been significant improvements in web technology in the past five years, and the cost has gone down. You can gain significant improvements with an investment now.
• Older site (5+ years). These sites are not optimized for new screen sizes and will appear very dated, which can hamper credibility.
• If you have new product lines or want to invest in some significant new functionality. First review the current platform to see if upgrades are possible, and at what cost. 
• Your business model has changed and the web is more important. If the website is playing a more significant role in your business, you need to make sure it's scalable for the inevitable improvements in the coming years.
• Significant navigation changes or additional content are needed. When changes like these are significant, it's a good time to revisit – new best practices may be incorporated at a modest price.

Is this something you have been thinking about fior your business? What other considerations do you have to share?