Garden Dome Foundations and Bases, Explained

Why no deep foundations are needed

Good news first: a garden dome doesn't need the concrete foundations a brick building does. That's a big part of why most owners can build one in an afternoon or a day, with no major groundwork. (Planning is a separate question: a garden dome is usually permitted development, but check with your local planning authority first.) The base still matters, though: a level surface and sound anchoring are what everything else depends on. Here's how to prepare for one.

A solid-polycarbonate geodesic dome is a lightweight structure, and its shape spreads loads evenly across the whole frame. It doesn't impose the concentrated point loads of a heavy masonry building, so it doesn't need deep concrete footings to carry it. What it needs instead is a firm, level surface to sit on and secure anchoring to hold it down against wind. That combination, a light structure plus good anchoring, is what keeps a dome stable without the cost, mess and permanence of foundations.

Base options that work

You've got a few good choices, depending on your dome and what's already in your garden:

• Our platform bases (Mini and Standard). The Hexa, with a phenolic hex-grip surface and a weather-sealed edge, and the Natural give you a ready-made level floor. Both pair with Ultra and Extreme domes.
• Decking. A popular and attractive option: a level timber or composite deck gives a clean, slightly raised platform that suits a dome perfectly and feels finished underfoot. Our wooden decking base pairs with every specification, and the 5 m Large sits on its decking base.
• Existing patio or paving. If you've a level, solid patio, a Mini or Standard dome can often sit straight on it. Check it's flat and stable first.
• Prepared ground pad. For a Mini or Standard, a compacted, levelled base (such as a gravel or slab pad) works well where there's no existing hard surface.
• Grass, with care. A Mini or Standard can sit on level grass for lighter use, but a firmer prepared base is better for longevity and stability, especially on exposed sites.

If you'd like one of ours, here's how they line up:

Base delivery can take longer than dome delivery, and you'll find them in the floors section of our shop.

The non-negotiable across all of them is level. A dome is built from individually numbered panels bolted together precisely; a level base makes the build straightforward and the finished dome true. If your garden slopes, our guide to domes on a slope or uneven ground explains the options.

Anchoring: the part that matters most

If you take one thing from this: anchoring is what keeps your dome safe in wind. Every GeoDomeX dome comes with anchoring brackets to fix the structure securely to the base, and Ultra and Extreme domes come with stainless steel bolts, nuts and anchors (an Original dome can be upgraded with the optional stainless steel hardware kit in the current dome configuration). On windy, exposed and coastal sites anchoring is essential, and Ultra or Extreme is the specification to choose. Fix it as intended into a solid base and an anchored dome is engineered for strength in wind and snow; skimp on it and no structure performs as it should. Our guide on how to anchor a garden dome goes through the methods.

If you'd rather leave the build to us, our Built for you installers can build the base, dome and anchoring for you, from £999 for a Mini or Standard and £1,995 for a Large, or anchor a dome you've built yourself from £249. Availability is subject to a postcode check, with extended-area pricing in some regions.

Decking and a dome together

Many buyers pair a dome with decking, and it's a combination that works on every level, practically and visually. A deck gives a level, durable, attractive platform, lifts the dome slightly off the ground for a clean finish, and creates a defined "room" feel. Our wooden decking base is made for exactly this. If you'd rather build your own, a simple level deck sized to your dome (with a little margin around the edge) is one of the tidiest ways to set one up. Plan the deck to your dome's footprint, leave room to move around the base, and make sure it's solid enough to anchor into.

Frequently asked questions