The greenest building is usually the one already standing. From this year, every Hallform project — however small — begins with a reuse audit. Demolition is now the last option we consider, not the first.

Why we changed the rule

Most of the carbon in a new building is spent before anyone moves in: in cement, steel, glass and transport. Keeping an existing structure can save more carbon than decades of efficient heating. We decided our briefs should start from that fact.

What the audit covers

We measure every wall, floor, window and door, test what we can and give each element a simple label: keep, repair or replace. The audit is drawn, photographed and shared with the client before any design work begins.

Keep

Structure is almost always worth keeping. Old concrete frames, brick walls and timber floors usually have decades of life left, and they give a building a depth that is hard to design from scratch.

Repair

Windows, floors, stairs and doors can often be repaired for a fraction of the cost and carbon of new ones. We work with local craftspeople who can refurbish old timber windows to modern standards with new seals and slim double glazing.

Replace — but reuse

When something must go, we look for a second life for it: on the same site, in another project or through a reclaimed materials dealer. On our last project, the demolished brick became the garden wall.

What it costs

Reuse is not always cheaper up front; surveys and careful repair take time. But across our last three projects, keeping between 60 and 80 percent of the existing fabric saved clients between 15 and 30 percent on construction cost.

What it changes in the design

Working with an existing building is a conversation rather than a monologue. The old structure sets rules we would never set ourselves, and some of our favourite rooms came from walls we were not allowed to move.

How to start

If you own a building and are thinking of replacing it, talk to us first. A reuse audit takes two to four weeks and usually changes the brief — and the budget — for the better.

We will publish the full audit template here in the journal later this year, free for any architect or building owner to use and adapt.