Tree Protection Zones (TPZs)

I mistakenly invoked an unrelated review tool, so ignore that. Here's the finished copy:

Tree protection zone paving was the deciding factor on a driveway project our team wrapped up this week. Established trees on site meant part of the works sat inside Tree Protection Zones (TPZs), and the usual constraints on hard surfaces near root systems shaped how the whole job was built.

Why tree protection zone paving is different to a standard driveway

A TPZ exists to stop compaction and sealing from cutting off water and air to a tree's root system. Solid concrete or asphalt laid across that zone can do real damage over time, which is why councils and arborists often require a permeable alternative wherever a driveway, path or hardstand crosses into protected ground. On this job, that meant running permeable concrete through the TPZ sections while the rest of the driveway used standard exposed aggregate concrete.

• Water and air can still reach the root zone through the permeable surface
• The surface stays firm and trafficable for everyday vehicle access
• It helps the project meet TPZ and council permeability conditions rather than working around them
• No separate drainage works are needed just to manage runoff over the protected area

Matching the finish across two different surfaces

The trickier part wasn't the engineering, it was the look. Where permeable concrete meets exposed aggregate concrete on the same driveway, any mismatch in stone colour or size stands out immediately. Our team spent time getting the aggregate blend in the permeable mix to sit alongside the exposed aggregate finish, so the transition between the two reads as one considered surface rather than a patch job.

That's the balance tree protection zone paving has to strike on a lot of residential jobs: satisfy the TPZ requirements without the finished driveway looking like it was built to two different briefs. Getting the stone matching right is a big part of that, and it's something we pay close attention to on every project that crosses a protected zone.

Planning a driveway near protected trees?

If your site has a TPZ in play, it's worth sorting out the paving approach early, before council conditions or an arborist report force a redesign partway through. Have a look at our tree protection zone paving page for more on how the system works, or get in touch to talk through your site.

We shared a few photos from this week's finished driveway on LinkedIn if you'd like to see how the two surfaces come together in practice.