Seven Strategies to Slash Your SharePoint Storage Spend

Is your SharePoint storage spiralling out of control? You’re not alone. Many organizations find themselves shelling out for Microsoft 365 storage brimming with duplicate files, inactive sites, and content that should have been deleted years ago. Read on for the top strategies to dramatically reduce storage costs, improve system performance, findability, and maintain regulatory compliance by:

• Implementing retention policies
• Reviewing inactive sites
• Rationalising preservation hold libraries
• Eliminating duplicates
• Optimising media and data storage
• Deleting unnecessary versions
• Using the right storage tier for the right job

Before we begin on any of these strategies we need to benchmark where we are currently so we can report on any success as well as gain insights on where best to direct our efforts. Follow the guide and templates here to create a capacity report which will help you answer the following questions:

• What SharePoint sites are the largest?
• What type of site uses the most storage?
• What’s the current storage for sensitive sites?
• How much storage is used by previous versions?
• Which sites were updated in the last few months?
• Which sites have just one owner?
• How many sites were created over 2 years ago?
• How many sites haven’t changed in 1 year?
• How many sites have over 1TB of files?
• A combination of any of the questions above…

Retention Policies

Organisations often have an obligation to ensure certain classes of information are accessible for a period of time; while other classes, particularly sensitive or protected personal information, needs to be deleted on request or when no longer needed.

This is best achieved by defining the classes and their retention periods, then organising  your information architecture around this –  so when people add content to a location, the retention policy is automatically defined, and the content is only stored for as long as necessary. For example, set emails to delete after seven years, draft documents after two years, and temporary project files after six months.

Start by conducting an information audit to understand what types of information your organization stores, then map these to legal and business requirements. Work with your legal and compliance teams to establish appropriate retention schedules that balance regulatory requirements with storage optimization goals. Keep your schedule as high-level as possible to avoid the pitfalls of going into the minutiae of every possible contingency.

Read more about archiving policies

Inactive Sites

Inactive sites are often the biggest storage waste in SharePoint environments. These abandoned project sites, old team workspaces, and forgotten collaboration areas can consume terabytes of storage while providing zero business value.

Start by reviewing inactive sites in the SharePoint admin centre – filter to sites with no activity in the last few months, then contact the owners asking if the sites can be disposed of.

Better yet, create a flow in Power Automate to schedule this review to run on a monthly basis. You may need to incorporate an exceptions step so owners of inactive sites that need to be kept but aren’t part of a retention policy aren’t niggled unnecessarily.

When contacting site owners, provide clear options:

• Archive the site where the content is of historical value
• Migrate important content to active locations; or
• Delete the site
• The consequences where no response to the notification is received

Preservation Hold Libraries

Your SharePoint compliance policies may create a hidden ‘preservation hold library’ on your sites that will store original versions of content even when people delete or modify files. While essential for legal compliance during litigation or investigations, these libraries can accumulate massive amounts of data over time – and you may not be aware they even exist.

To see if a site has a hold library, head to site settings then ‘storage metrics’ – if it has one, it’ll be listed there with the other contents of the site. You’ll need someone assigned a Compliance Manager role to be able to see what’s in it however.

Regularly review active preservation holds with your legal team to determine which can be released. Once a legal hold is no longer required, the preserved content should be permanently deleted to free up storage space. Establish clear processes for hold management, including documentation requirements and approval workflows for creating and releasing holds.

Consider implementing automated workflows that notify legal teams when holds reach certain age thresholds, prompting regular reviews of whether continued preservation is necessary.

Duplicate Files

Duplicate files are storage space killers that multiply across SharePoint sites, OneDrive accounts, and email attachments. People often save multiple copies of presentations, upload the same images to different libraries, or create ‘backup’ versions in various locations.

Couple of options are available to resolve this:

• Deploy third-party de-duplication tools (many are available). These typically scan your tenant to identify identical files, using file hash comparisons to find exact duplicates and similar content analysis to identify near-duplicates with minor differences
• Use Power BI to connect to the sites you want to review – the SharePoint Duplicate Files Report is a great starter for ten.

Prevention is always better than the cure, however – so build the systems to discourage duplicate storage, such as implementing centralized asset libraries for commonly used images, templates, and presentations. Encourage people to link to master documents rather than creating copies, and establish clear folder structures that make it easy to find existing content.

Redundant Compressed ‘Zip’ Files

People often upload compressed files and then extract their contents into the same library, effectively doubling storage consumption and you’ll have duplicates without knowing it.

Having a clear policy for compressed file handling is crucial – either store the compressed archive or the extracted contents, but not both. Create automated workflows that detect when compressed files are uploaded and guide people through proper extraction and cleanup processes; or incorporate zip file deletion when adding zip file extraction to a Library Column.

Another option is to encourage people to extract compressed files locally, review contents, and then upload only necessary files to SharePoint. This approach also improves searchability and collaboration since individual files are more accessible than archived content.

Finding the duplicates is relatively straightforward – run a wildcard * search, then filter to .zip, .7z, .rar, .gz, and .bz2 file types, sort by size, then head to the folder the compressed file is stored in. Is there a folder there with the same name as the compressed file? Bang, you’ve found yourself a dupe to delete.

Optimizing Storage by Content Type

Different content types have varying storage requirements and usage patterns. Video files, high-resolution images, and large datasets take up lots of storage and there may be better solutions for them.

Bunch of ways to address this:

• Move infrequently accessed video content to Azure Media Services
• Use a specialized media streaming platform such as Kaltura.
• Compress images according to their intended use – web images don’t need print-quality resolution for instance.
• Move large datasets in MS Lists or spreadsheets to Fabric or another big data platform where they can be more cost-effectively stored and analyzed.
• Encourage people to always ‘compress images’ before saving PowerPoint presentations. This will remove cropped areas and save the images in the file to a size appropriate for the presentation’s use
• Implement upload policies that prevent storing inappropriate content types in SharePoint. For example, restrict video uploads above certain file sizes or require approval for large media files.

Redundant Versions

SharePoint’s version control is fantastic for collaboration and compliance, but unlimited versioning can consume enormous amounts of storage – 50 versions of a document effectively uses 50 times the storage.

Review version settings across all document libraries and establish reasonable limits. For most business documents, 10-20 versions provide adequate history while preventing runaway storage growth. For frequently edited documents, consider implementing major/minor versioning with automatic cleanup of draft versions after final publication.

Create policies for version management that balance collaboration needs with storage efficiency. For example, keep all versions for active projects but reduce to major or final versions on project completion.

Archive Tiers

The Microsoft 365 Archive tier offers 75% lower storage costs – around £0.05 per GB vs £0.20 for standard storage. This is accomplished by compressing the content, and storing it on cheaper drives in remote locations. Accessing archived content is more expensive on the other hand, as it needs to be decompressed, retrieval times are longer, and bandwidth costs are higher for data transfer.

The key is identifying content that’s rarely accessed but must be retained for compliance or historical purposes. Financial records, completed projects’ sites, and old marketing materials are perfect candidates for archiving as they’re seldom needed but can’t be deleted until our retention schedule says so.

When implementing archive tiers, factor in the total cost of ownership including retrieval fees. Content that’s accessed even monthly may be more cost-effective in standard storage tiers. Archive storage is great for ‘write once, read rarely’ situations where content needs storing for compliance requirements rather than active business use.

So documents that haven’t been accessed in six-twelve months might go to archive storage, or a retention schedule could specify project sites be moved to the archive tier six months after completion

Work with your IT team to configure Azure Storage lifecycle policies that automatically transition content between tiers based on your organization’s usage patterns and cost optimization goals.

Implementing Your Storage Optimization Strategy

Success requires a systematic approach combining technology, policy, and user education. Start with the highest-impact areas – inactive sites and duplicate files typically offer the quickest wins. Then implement longer-term strategies like retention policies and archive tiers.

Regular monitoring and maintenance is essential – storage optimization isn’t a one-time project but an ongoing operational requirement. Establish monthly or quarterly reviews of storage utilization, policy effectiveness, and user compliance.

Do remember your storage strategy should enhance, not hinder, productivity. Work closely with people to understand their needs and ensure that cleanup efforts don’t accidentally delete important content or disrupt workflows.

By implementing these strategies, most organizations can reduce their storage costs by 40-60% while improving findability, system performance, and maintaining full compliance with regulatory requirements.