For years, SharePoint architecture resembled a rigid family tree. You had a main site collection, and underneath it, a cascade of subsites for departments, projects, and teams. An HR subsite might contain a Payroll subsite, which in turn held a Benefits subsite. This nested structure seemed logical, but it created significant problems.

Moving a team from one department to another meant migrating their entire subsite, a process that often broke URLs and shattered user bookmarks. Permissions were a nightmare; they cascaded down from parent sites, creating a complex web of inherited and unique access rights that was difficult to audit and manage. This rigidity made it hard for the digital workspace to adapt to the fluid nature of modern organizations.

Instead of being buried in a hierarchy, each site—whether for a department, a cross-functional project team, or a regional office—is its own top-level entity. This immediately solves the old problems. Permissions are managed per site, creating clean boundaries. And since a site's URL is no longer dependent on its parent, it can be logically reorganized without breaking links.

If every site is an island, how do you create a cohesive intranet experience? This is where Hub Sites come in. A hub site is the connective tissue for the modern flat architecture. It acts as a central portal, linking together logically related sites into a 'family' without forcing them into a rigid physical structure.

When a site joins a hub, it inherits a shared navigation bar, a consistent theme and branding, and the ability to roll up content. News and events published on any associated 'spoke' site can automatically appear on the hub's main page. This gives users a consolidated view while allowing each team to manage its own content independently.

This model provides incredible flexibility. Let's say a project team that was part of the Marketing hub is spun off into its own department. The site administrator can simply disassociate the project site from the Marketing hub and associate it with a new departmental hub. The site's content, permissions, and URL all remain unchanged. The only thing that changes is the shared navigation it inherits. This is a simple administrative task, not a complex migration project.

In this flat world, there are two primary types of sites you'll create and connect to hubs: Team Sites and Communication Sites.

A department like Human Resources would have both. They'd use a private, M365 Group-connected Team Site for their internal collaboration—drafting policies, managing employee files, and planning initiatives. This is where the work gets done.

Simultaneously, HR would run a public-facing Communication Site associated with the main company hub. This is where they broadcast information to the entire organization: official policies, benefits enrollment guides, and company-wide announcements. It's a polished, curated experience for consumption, not collaboration.

With this architecture, navigation becomes a deliberate act of planning rather than an accidental byproduct of structure. You need to consider two main levels:

1. Global Navigation: This is the persistent, top-level navigation for your entire SharePoint tenant, often configured in the SharePoint app bar. It should link to the most critical, company-wide resources: the main intranet portal (a hub), HR, IT, and other key departments. It's the map that ensures no one gets lost, no matter where they are.

2. Hub Navigation: Each hub site has its own navigation bar, which is shared by all associated spoke sites. This provides context-specific navigation. When you're in the Marketing hub, you see links to the Social Media team site, the Brand Assets library, and the latest Campaign communication site. This layer connects the family of related sites.

This layered approach allows you to build an intranet that is both globally consistent and locally relevant, scaling gracefully as your organization evolves.

This shift from nested subsites to a flat, hub-centric model is the single most important concept in modern SharePoint information architecture. By embracing it, you create a digital workspace that is flexible, scalable, and far easier to govern.