Bases, positioning and installation

Position affects light, temperature, wind loading and whether you enjoy using the greenhouse. Orientation is useful, but it is not the only variable: a slightly imperfect compass alignment with open light and easy access can be more successful than a theoretically ideal ridge squeezed into shade.

Treat the base as part of the structure

The finished support must be level, stable and compatible with the manufacturer's anchoring method. A perimeter base can leave growing soil inside; paving gives a clean working surface; concrete is durable but changes drainage and is difficult to reverse. The exact greenhouse dimensions, not the nominal “6 × 4” label, should set out the base.

Planning rules are devolved and do not apply identically across the UK. Listed buildings, designated land, flats, leasehold homes and restricted permitted-development rights need additional checks. Use our greenhouse planning permission guide to reach the correct national source, and contact the local planning authority when the position or status is uncertain.

For electrical supplies, use a competent electrician and equipment suitable for the environment. Water, condensation and metal framing make improvised extension-lead arrangements a poor substitute for a correctly designed installation.

Mark out the working zone, not just the frame

Add the door movement, an approach path and the strip needed to clean the outside. If the frame arrives flat packed, reserve a separate level area long enough to lay out rails without bending them. A measured rectangle of string and stakes is cheaper than discovering that the finished door meets a fence post.

Work through the site before choosing the foundation

Begin with greenhouse positioning and UK orientation. Observe the site at several times of day rather than treating a compass direction as a complete answer. Buildings, fences and trees can change the useful light more than a small change in ridge alignment.

Next check boundary conditions and clearance around the greenhouse. Planning limits and practical maintenance room are different questions: a permitted position can still be too cramped to assemble or clean. For nearby mature trees, use the greenhouse-near-trees guide before excavating around roots.

Match the foundation to the structure and growing plan

The base comparison is the decision page. Follow it with the guide for the chosen method: paving slabs, a concrete base or a perimeter foundation. If you want soil beds inside, read greenhouses on soil to separate planting ground from the support carrying the frame.

An existing patio or deck should not be accepted merely because it looks flat. The patio-installation guide covers the checks needed before reusing paving. A greenhouse on decking needs particular attention to the supporting structure and approved installation; general garden advice cannot establish its load capacity.

Use the exact instructions for the final build

Halls' base guidance explains the importance of a strong, level and square foundation. That is useful background, not a replacement for your own model's drawings. Follow how to anchor a greenhouse with the approved fixing plan, then use the assembly-safety checklist to organise parts, helpers and glazing safely.

For permission, the Planning Portal outbuilding guide is an England starting point, not a UK-wide answer. Our nation-by-nation guide links to the relevant rules. Resolve uncertainty with the local planning authority before you order or begin groundworks.