Modular extension delivery and crane access

What fits on a lorry

Width is the limit people know about. Height is the one that reroutes lorries. A finished module is around three metres tall and rides on a trailer bed about a metre off the road, so the load stands close to four metres high. Bridges lower than 16 feet 6 inches are signed, and the haulier plans a route that avoids them; the route to a house under a railway arch can be much longer than the map suggests.

Length is rarely a problem for an extension. Modules of eight or nine metres sit comfortably on a standard trailer. The awkward part is the last two hundred metres: a tight junction, a row of parked cars, a weight limit on a small bridge. Makers carry out a route survey before they commit to a module size, and you can help by telling them about pinch points they will not see on a satellite image.

Larger rooms are simply made in two or three modules and joined at your house. The joint lands on a line you agree in advance, usually where a beam or a change of ceiling would be anyway.

Choosing the crane

A crane's rating describes what it can lift close to its own centre. Capacity falls quickly as the load moves away, so a machine sold as a 60-tonne crane may manage only a few tonnes at 25 metres. That is why the distance you paced from kerb to base matters. Lifting from a drive straight onto a base beside it needs a small crane. Lifting the same module over a two-storey house from the far kerb can need one several sizes larger, with the hire cost to match.

The crane also needs a firm, level place to stand with its outrigger legs fully extended, which takes a patch roughly seven or eight metres square. The load under each leg is heavy and concentrated. Pavements with cellars or service ducts beneath, block-paved drives and soft verges may need steel mats or be ruled out altogether.

Where a mobile crane cannot work, there are three fallbacks: a lorry-mounted crane for light pods, a compact tracked crane taken through a side passage, or a room sent as panels and assembled by hand.

Who plans the lift

The law on lifting is clear and it protects you. Every lift has to be planned in advance by someone competent, properly supervised, and done safely. In practice the plan is written by an appointed person, who visits or studies the site, chooses the crane, sets out where it stands and writes a method for the day.

There are two ways to hire a crane, and the difference is who carries that duty. Under a contract lift, the crane company supplies the appointed person, the plan, the supervisor and the insurance for the load. Under plain crane hire, the hirer does all of that and the crane firm provides only the machine and operator. For a house, you want your extension firm either to buy a contract lift or to employ its own qualified appointed person. Ask which, and ask to see the lift plan a week before the day.

Permits, closures and parking

A crane standing on a public road or pavement needs a licence from the highway authority, which is your county, unitary or borough council. If the road cannot stay open around it, the council must make a temporary traffic order to close it. Councils set their own fees and notice periods; several weeks is normal for a closure, and some ask for three months. Parking bays in the way are suspended through a separate request.

Your extension firm should apply for all of this and build the lead time into its programme. What you can do is tell them early if the street has a bus route, a school, permit parking or a market day, because each of those limits the dates a council will accept.

If the module will pass over a neighbour's garden or roof, their agreement is needed. Nobody has a right to swing a load through someone else's airspace. Knock on the door well before the day; most neighbours say yes when asked and object when surprised.

Wires, trees and weather

Overhead electricity lines are the hazard a lift plan treats most seriously. The network operator for your area can fit temporary shrouding to low-voltage lines or switch them off for the day, but it needs booking weeks ahead. Telephone wires across the street can sometimes be dropped and rehung by the telecoms provider. Tree branches over the highway belong to the council or a neighbour and cannot simply be cut.

Wind is what cancels lifts. A finished room hanging from a hook behaves like a sail, and the crane's own limits and the lift plan will stop work well before it feels stormy on the ground. Agree in the contract who pays for the crane, the road closure and the lorry if the day is called off for weather. A fair contract shares that risk or gives it to the firm; it should not fall on you by default.

On the day

Expect an early start. The crane arrives, sets up and is tested. The lorry is called forward. If the module passes over the house, everyone inside leaves until it is down, and a neighbour whose house is under the path may be asked to do the same. Each lift takes minutes; the waiting, slinging and levelling take hours.

By mid-afternoon the room is on its base and fixed. As a domestic client you carry few legal duties for site safety, because the regulations pass them to the contractor. Your part is practical: move cars the evening before, keep children and pets indoors or away, and resist the urge to stand close with a camera.

Questions worth asking a firm

• Have you surveyed the route and the street, and what module width did that give?
• Is the lift a contract lift, and who is the appointed person?
• Which permits do you apply for, and are the council's fees in your price?
• What does the module weigh, and what size of crane does the plan call for?
• If wind stops the lift, who pays for the second attempt?
• How will you protect the drive, the pavement and the neighbour's property, and whose insurance covers them?

A firm that does this every month will answer without hesitating. Vague answers here are a better warning than anything in a brochure.