Garden Reinstatement Cost Estimator

Garden reinstatement after a UK extension typically costs £2,000 – £6,000 for a standard rear-garden scope: a patio, some drainage, fencing, and re-turfing where the build churned up the lawn. It is one of the most commonly under-budgeted parts of a project, because the work happens last and rarely appears on the builder's quote.

This estimator turns the areas you need putting right into a realistic range. Enter your soft landscaping, patio, and driveway areas, add fencing length, and tick drainage if the building control officer wants surface water dealt with. The result splits by element so you can hand a clear brief to a landscaper rather than accepting one lump-sum number.

What garden reinstatement covers

External works cover the ground a build disturbs and the finishes that make the garden usable again. Soft landscaping (topsoil, turf, and seeding), fencing, and driveway reinstatement are priced per square metre or per metre run, so the tool above scales them with the areas you enter. Hard paving is the item that moves the total most: a 20m² installed patio typically runs £1,400 – £4,000, and the rate per m² climbs steeply once you move from concrete flags to sandstone or porcelain.

Drainage is the element people forget. Surface water coming off the new roof has to go somewhere, and a channel drain feeding a new soakaway adds £700 – £2,500. Anything beyond a basic reinstatement (larger patios, premium materials, extensive drainage rework, or a full garden redesign) pushes the whole job into the £3,000 – £10,000 bracket.

Sequence the works, do not rush them

External works are the tail end of the programme, but they carry two hold points that catch people out. First, the building control officer must inspect and sign off any drainage runs before paving covers them. Pave over an uninspected drain and you may have to rip finished work up again. Second, the finished patio surface has to sit well below the damp-proof course line on the extension wall. A patio laid too high bridges the DPC and causes rising damp, which is the most commonly reported post-extension defect.

Book the groundworker or landscaper during second fix, not after completion. Good contractors are booked several weeks ahead, and mortar for patio laying needs mild weather, so a build finishing in autumn often means the patio waits until spring.

A worked example

Take a 30m² rear garden that the build churned up, with a 15m² patio and a new soakaway to handle roof water. The soft landscaping is priced per square metre in the tool above, so enter the lawn area and it scales the topsoil and turf line for you. The patio scales from the £1,400 – £4,000 benchmark for a 20m² installation, and ticking the drainage box adds the £700 – £2,500 range for the channel drain and soakaway. Add fencing by the metre if a boundary panel came down for access.

The calculator sums these into the total shown above. Treat it as a planning figure to carry in your overall budget, then use it to sanity-check the landscaper's quote element by element rather than accepting one headline price.