First greenhouse checklist

Before you choose a model

Define the first-year growing plan

Write down the crops and jobs that matter most. Seed trays and cuttings need accessible staging. Tomatoes and cucumbers need height, ventilation and strong supports. Pots moved in for winter need clear floor space and a wide route. If the list is mostly herbs, salads and seedlings, a tall wall greenhouse or mini growhouse may be more efficient than a walk-in.

Avoid planning the interior around the small size of plants in spring. A few vigorous summer crops can remove the aisle and block vents surprisingly quickly.

Measure the whole working area

• Mark the exact base dimensions from the product specification.
• Add the overall dimensions, including roof or gutter overhangs.
• Mark the open or sliding door and the approach path.
• Allow room to clean the glazing and reach gutters.
• Reserve a separate area for unpacking and assembling long components.
• Walk the delivery route and measure gates, turns, steps and narrow passages.

Photograph the marked plot from several angles. It is easier to spot conflicts with a downpipe, fence post or tree branch when reviewing a clear outline than when imagining a finished greenhouse.

Position and permissions checklist

Choose a position with useful daylight, manageable wind exposure and no obvious risk from falling branches. Look at the site at different times of day rather than relying on one sunny visit. A location that receives morning light and remains accessible can be more useful than an all-day sun trap with poor ventilation.

Check boundaries, roof eaves, drains and services before digging. Greenhouses often fall within general outbuilding rules for houses, but planning circumstances differ for listed buildings, designated land, flats, leaseholds and properties where permitted-development rights are restricted. Ask the local planning authority when the property or position creates doubt.

Base and anchoring checklist

Read the exact instructions before preparing the foundation. Confirm whether a perimeter base is included, sold separately or not part of the system. The supporting surface must be level enough to keep doors and panels square, stable over time and compatible with the specified anchors.

Decide whether the interior will be paved, gravelled or planted into soil. That choice affects drainage, cleaning, pests and how staging is fixed. If you use a perimeter foundation with soil inside, plan the path before assembly. If you pave the whole area, include falls and drainage without twisting the greenhouse base.

Never treat the weight of the frame as its anchoring system. Wind acts on a large glazed surface, so use the manufacturer's fixing points and hardware suitable for the foundation.

Delivery and assembly checklist

• Confirm the number, length and weight of packages where published.
• Arrange a dry, secure place to store panels and fixings.
• Check how many people the instructions require.
• Choose a calm forecast and allow more time than the shortest estimate.
• Sort fixings into labelled groups without removing part references.
• Check the frame for square at each stage rather than correcting it after glazing.
• Wear suitable gloves and eye protection for the materials being handled.
• Keep children and pets away from the assembly area.

Large glass panes demand especially careful handling, while lightweight polycarbonate panels need control in wind. Do not substitute adhesives, extra holes or improvised fixings unless the manufacturer approves them.

Ventilation and temperature checklist

Count the opening vents and decide how replacement air will enter. A roof vent releases hot air; an open door or low vent helps cooler air replace it. Automatic vent openers are useful when compatible, but they do not remove the need to inspect hinges, seals and opening clearances.

Place a maximum-and-minimum thermometer away from direct sun so you can learn the overnight low and daytime peak. Use those readings to decide whether shading, fleece or extra ventilation is actually needed.

Water checklist

Identify the water source before filling the greenhouse. A nearby outdoor tap simplifies regular watering; a water butt can collect from compatible gutters; cans remain reliable for small spaces. Keep hoses and irrigation tubes away from the aisle and door.

Watering needs change with weather, crop size and container volume. A timer is not a substitute for checking the compost and emitters. Start with a simple system you can inspect, then add automation when the crop layout is stable.

Interior layout checklist

Draw the door, aisle, vents and usable height to scale. Add staging only where it does not block access or force tall crops into the eaves. Keep the main path clear enough to carry a watering can and turn safely. Shelves above staging are excellent for light trays but can shade plants below.

Leave at least one flexible area. It may become a potting surface in spring, support tomatoes in summer and hold tender pots in autumn. A completely fixed interior often feels efficient for one month and restrictive for the rest of the year.

The day-before checklist

Recheck the base level, diagonals and anchor positions. Compare the delivered model and glazing option with the order. Read the instructions from beginning to end, charge tools, gather protective equipment and move unrelated garden furniture away from the assembly route.

After construction, inspect every panel retainer, door stop, vent and anchor before loading the greenhouse with plants. Keep the manual and component references somewhere dry; they are valuable when ordering replacement parts later.

If you have not chosen a structure yet, start with how to choose a greenhouse. For foundations and siting, continue to greenhouse bases, positioning and installation.

For model-specific preparation, start with the maker's manual. The Halls assembly library provides an example of the documents you should obtain before buying, rather than discovering foundation or glazing requirements after delivery.