Why the Secretary of the Interior’s Standards Matter — and Why We Use Them

Historic buildings are more than structures — they’re part of our cultural record. They hold the marks of the people who built them, the communities they shaped, and the events they witnessed. Preserving that story requires consistency, accountability, and a framework that prevents well-intentioned work from doing accidental harm. That’s exactly why the Secretary of the Interior’s Standards for the Treatment of Historic Properties exist.

These Standards are the foundation of preservation practice across the U.S. They guide federal agencies, state historic offices, local commissions, architects, and builders. But at their core, they’re simply a clear set of principles: repair what can be repaired; replace only what must be replaced; keep historic character intact; make new work compatible but clearly new; and avoid guesswork or recreations.

Treeline uses these Standards not because we’re always required to, but because experience has proven that they lead to better, more durable, more respectful work.

Why These Standards Exist

The Standards were created to solve a very real problem: historic buildings were being “restored” in ways that erased the very things that made them historic. Over-restoration, inappropriate materials, unnecessary demolition, or heavy-handed upgrades caused irreversible loss of character nationwide.

The Standards provide a way to protect historic integrity while still allowing buildings to evolve, remain functional, and meet modern needs.

They exist to:

• Protect original materials and craftsmanship

• Ensure repairs don’t introduce future failures

• Keep historic character visible and understandable

• Balance safety, performance, and authenticity

• Provide a common language for owners, A/E teams, and contractors

They’re not aesthetic rules — they’re safeguards.

Why These Standards Are Important

Historic buildings are resilient, but only if they’re treated with respect. The Standards matter because they prevent avoidable damage such as:

• Moisture traps caused by incompatible materials

• Structural problems created by unnecessary removal

• Loss of detail from over-sanding, re-profiling, or “modernizing”

• False history created by guesswork

• Systems integration that scars or obscures defining features

Following the Standards protects not just the building’s appearance, but its integrity, performance, and long-term sustainability.

Why Treeline Uses the Standards — Even When They’re Not Required

For us, this isn’t paperwork or compliance. It’s simply the right way to approach historic structures.

We follow the Standards because:

• They align with our repair-first philosophy

• They reduce lifecycle cost for owners

• They prevent unnecessary scope, demo, and disruption

• They create clear expectations between the design team and contractor

• They ensure our work strengthens the building instead of overwhelming it

Most importantly, the Standards support our ethic: preserve what matters, upgrade what must be upgraded, and respect the resource at every turn.

Looking Ahead

As we share our upcoming preservation series — from in-kind repairs to adaptive reuse — you’ll see these Standards reflected throughout. They’re not a constraint; they’re a guide to doing high-quality, long-lasting work.

Good preservation isn’t magic. It’s discipline, judgment, and a shared commitment to honoring the buildings we’re fortunate to inherit.