Building a Garden Room Near a 150-Year-Old Oak: How to Avoid Root Damage?

As a forester, I recommend measuring the trunk diameter about 5 feet above the ground, then multiply that number by 10 to find the critical distance from the trunk where you shouldn't build. If you can't follow that, consider laying a patio on sharp sand for your garden room base, making sure to use mortar to keep the sand in place. Another option is to float a wooden floor on insulation layers. There are definitely greener building techniques available too!

It's risky to put in standard strip foundations close to the oak's root zone. Instead, look into using pile and beam construction with screw piles, which are way less damaging. It's also crucial to have a certified arborist assess the root zone so you don’t compromise more than 20% of it. Remember that construction can affect the tree's health in the long run, so keeping a distance is best. And definitely set up protective fencing around the root area during your work!