Garden Room Foundations Explained

The foundation you can’t see is what determines whether your garden room lasts decades or starts shifting within a few years. Here’s how the common options compare — and why every Oaklight garden room sits on solid concrete.

Common foundation types

• Concrete base — the most robust option, ideal for larger or heavier rooms, and for gardens with firm, stable ground
• Groundscrew (helical pile) foundation — steel screws driven into the ground; faster to install, minimal excavation, and better suited to gardens where digging is difficult or you want to protect tree roots and drainage
• Paved or slab base — used in some lighter-weight applications, though less common for fully insulated, all-year garden rooms

Why we use concrete for every build

We build every Oaklight garden room on a solid concrete base: compacted hardcore, a damp-proof membrane and poured concrete, reinforced where the ground needs it. It costs a little more than screws or slabs, but it gives a stable, level, long-lasting base that suits a fully insulated, all-year room.

Ground conditions (clay, sand, chalk, or made-up ground), the slope of your garden, nearby trees and drainage all affect how the base is designed — its depth, size and any reinforcement. That’s why we carry out a proper site survey before finalising your design and quote.

Why it matters long-term

An undersized or poorly matched foundation is one of the leading causes of doors sticking, gaps opening in cladding, or damp getting in over time. It’s not a place to cut corners, even though it’s the part of the build you’ll never actually see once it’s finished.

Every quote we provide includes the foundation specified for your exact plot — no vague “base included” line item. Get in touch to arrange your site survey.