What does greenhouse installation actually involve?
Greenhouse installation in the UK means five things in sequence: choosing the spot, preparing a level base, assembling and squaring the frame, glazing it, then anchoring it to the ground. For a small aluminium model two people can do the lot in a weekend. Larger or wooden frames usually run to two days.
Plenty of guides jump straight to bolts and panels. The decisions that matter most happen before you open the flat-pack: where the greenhouse sits, what it stands on, and whether you build it yourself. Get those three right and the build runs easy. For the bolt-by-bolt build of our own greenhouse, see our weekend assembly guide, and for the numbers, our greenhouse installation cost breakdown.
Choosing and preparing the site
Site choice does more for your plants than any spec on the box. The Royal Horticultural Society advises putting a greenhouse where it gets uninterrupted sun throughout the day, and screening it from cold northerly and easterly winds that hold spring temperatures down. A spot that bakes from morning to dusk in June can fall into the shadow of a fence or conifer by October, so watch the light across a full day before you commit.
Which way should it face?
Orientation depends on when you will use the greenhouse most. Per the RHS, an east-west ridge slightly extends light levels during winter, which suits early sowings and overwintering. A north-south ridge suits summer crops like tomatoes, because both sides catch several hours of sun through the season. Decide by the months you garden hardest, then point the ridge accordingly.
Getting the ground ready
Whatever base you choose, the ground under it has to be level and firm before anything goes up. Across the trade guides the rule holds: a base out of level or out of square invites the frame to shift or lift in strong winds. Clear the turf, compact the soil, and check the fall with a long spirit level. Square a rectangular base by measuring both diagonals and adjusting until they match, the same trick joiners use to true a door frame.
The base decision: anchors, slabs or concrete
Ground anchors are standard, so no concrete foundation is required. For extra stability, we recommend a firm, level base. The simplest reliable base is a bed of paving slabs, the kind most gardens already have to hand: level them on compacted ground, anchor the frame to them, and the greenhouse stands square and solid. The trade base guides treat anchoring into firm ground as a legitimate method in its own right, so three mainstream UK approaches exist and the right one depends on your ground.
| Base type | Roughly what it is | Best for |
|---|---|---|
| Ground anchors | Steel anchors driven at the corners and along the sides into firm, compacted ground | Allotments and firm lawns; the quickest option for two people |
| Paving-slab perimeter | Paving slabs levelled on compacted ground, as a perimeter or a full bed | Most gardens: our recommended base, commonly available and quick to level |
| Concrete pad | Concrete over compacted hardcore; the strongest and longest-lived option | Mostly commercial growers; rarely needed at home, and a contractor job |
Anchors suit firm or compacted ground, an allotment or an established lawn. They rule themselves out on wet, soft, sloping or recently disturbed ground, where the soil cannot hold them and a slab or pad earns its place instead. A firm, level base under any greenhouse improves stability and stops doors binding as the seasons move, which is why we recommend one even though concrete is not universally required. For our own greenhouses, ground anchors hold the frame down without a poured foundation, so most gardens need no groundwork beyond levelling.
DIY or professional install: which suits you?
Most flat-pack greenhouses are built by the owner and a helper over a weekend. A professional install makes sense for larger models, glass glazing, awkward or sloping sites, or when you have no second pair of hands. Here is the honest split.
Doing it yourself
DIY works if you are comfortable with flat-pack furniture, you have a clear day plus a helper, and the site sits reasonably flat. Budget a weekend: one day for the base, one day for the frame and glazing. According to the fitter guide from GreenhouseStores, a 6x4ft takes roughly 4 to 5 hours for two people, a 6x8ft around 6 to 8 hours, and an 8x12ft can run to a second day. Wooden frames take about 50 per cent longer than the aluminium equivalent, so factor that in if you build in timber.
You need a second person throughout. One of you holds the end walls upright while the other connects the side bars, and glazing wants two pairs of hands. The same fitter guidance is firm on one safety point: never glaze in strong or gusty wind, and wear goggles and gloves with a glass sucker for handling panes. That safety limit covers manhandling panels in gusts on the day, and says nothing about how the finished greenhouse stands up to weather.
Why a Waldenhaus greenhouse does not need a paid fitter
Our greenhouses are built to go up by hand. Each one arrives as pre-cut, numbered panels with an illustrated step-by-step guide, so two adults can raise it over a weekend with everyday tools and no trade skills. The ground anchors hold the frame down, so no concrete is needed and the groundwork stays light. For a Waldenhaus greenhouse you do not need to pay a fitter, and the install fee stays in your pocket.
If you would rather not lift a spanner, or the site is steep or tight, a fitter is still an option, and our cost guide covers what that runs to. Most people with a helper and a free Saturday will not need one. Follow the numbered panels in order, keep the bolts finger-tight until the frame stands square, then anchor it down, and you will have built it yourself in a weekend.
Prefer to see it first? Our own step-by-step build video runs the whole assembly, the way two adults would tackle it over a weekend.
Bringing in a professional
A trained two-person team can install a 6x8ft in under 4 hours, per the same retailer guide. A professional install typically covers assembly, glazing, door and vent fitting, frame squaring and site cleanup, usually with a 12-month workmanship warranty. Costs vary by size and glazing, so rather than quote a figure here we have put the full breakdown in our greenhouse installation cost guide, with timber totals in our wooden greenhouse cost guide.
The install order, and three craft rules
Professional fitters work in a set sequence, and it pays to know it even if you never lift a spanner. Prepare the level base, assemble the base frame, build the end walls flat and stand them upright, connect the side bars, fit the ridge bar, hang the door and vents, glaze last, then anchor down. Glazing goes in near the end because the panels lock a squared frame in place. Our full weekend assembly guide walks every step.
Three habits separate a frame that lasts from one that rattles. Keep every bolt finger-tight until the whole frame stands, then go round and tighten so it settles square before anything locks. Leave shelving unloaded for 24 hours, and run a bolt check at six months. Our greenhouses arrive as pre-cut, numbered panels with an illustrated guide, so two adults can follow this order over a weekend without specialist tools. That is the thinking behind the NORDIC Swedish pine greenhouse.
How long does a greenhouse take to install?
Plan a weekend. Give one day to the base if you are laying a slab or pad, and one day to the frame and glazing. A small aluminium 6x8ft takes about a day for two people. A large model or a wooden frame can stretch to two full days, partly because timber takes around half as long again to assemble as aluminium.
Twin-wall polycarbonate glazing speeds this up against glass. The panels weigh less to lift, handle more safely if a gust catches you, and screw-fix rather than clip into place. Your build day runs more forgiving as a result, though you still want a calm one.
Do you need planning permission for a greenhouse?
Usually you do not. A domestic greenhouse counts as an outbuilding and falls under permitted development if it stays within the size and siting limits. Rules vary by nation and area and change over time, and this is general guidance rather than legal advice, so check the official source for where you live before you build.
England
The Planning Portal sets the limits for England. A greenhouse must sit no higher than 4m with a dual-pitched roof or 3m with any other roof, with eaves no higher than 2.5m. Within 2m of a boundary the maximum height drops to 2.5m. Nothing should go forward of the principal elevation, the front wall of the house, and buildings must not cover more than half the land around the original house. Listed buildings need permission for any outbuilding, and designated land such as national parks, areas of outstanding natural beauty and conservation areas carries extra restrictions. An Article 4 direction can remove permitted development rights altogether. The Planning Portal notes its guidance covers England, and that policy in Wales may differ.
Scotland
Per mygov.scot, a greenhouse should sit at the back of the house and must not take up half or more of the grounds behind the home. It must be no higher than 4m, with eaves no higher than 3m, and any part within 1m of a boundary must be no higher than 2.5m. In a conservation area or the grounds of a listed building the footprint is capped at 4 square metres, and the building cannot become a separate dwelling.
Wales, Northern Ireland and building regs
Wales and Northern Ireland set their own rules, which we have not detailed here, so check the Planning Portal Wales note and your local planning authority. On building regulations, domestic greenhouses are generally exempt as lightweight single-storey structures not used for sleeping, though any mains electrics must comply with Part P. Your council planning department will confirm in a phone call.
Frequently asked questions
Can I install a greenhouse on grass?
Yes, if the ground holds firm. Ground anchors grip well in an established, compacted lawn, which is why anchors are standard and no concrete foundation is required. Level the ground first, and remember a firm base improves stability. On soft, wet or recently dug ground, lay slabs instead.
Do I need a foundation for a greenhouse?
No concrete foundation is required, because ground anchors are standard and hold the frame down. For extra stability we recommend a firm, level base, which keeps doors aligned and the frame square through the seasons. Concrete pads serve mainly large commercial structures.
How level does the base need to be?
Within 5mm across the full diagonal, per professional fitter guidance. Check it with a long spirit level before assembly, and square the base by matching both diagonal measurements. A few minutes here saves a frame that twists or a door that will not close.
What delivery should I expect from Waldenhaus?
Delivery to the UK mainland is free and typically takes around 1 to 2 weeks. Your greenhouse arrives as numbered, pre-cut panels with an illustrated guide, ready for two adults to build over a weekend once the base sits level.
Get the site, the base and the squaring right, and a greenhouse will stand straight and dry for years. Walk the garden this weekend, watch where the sun falls, and decide whether your ground will take anchors or wants a slab. That single decision shapes everything that follows.
