House Extension Builders in Maidstone

An extension is usually the biggest building job a homeowner takes on, and much of the risk sits in the planning before anyone digs a trench. Work out the route early and your builders' quotes will be more accurate.

Start with the council. Most of the area is in Maidstone borough, but Aylesford, Larkfield, Ditton and Kings Hill are in Tonbridge and Malling, and Walderslade and Lordswood are in Medway. Planning applications go to the council for your address.

Many single-storey rear extensions can go ahead under permitted development, without a full planning application. The basic limits are 3 metres deep for a terraced or semi-detached house and 4 metres for a detached house, no more than 4 metres high, and materials similar to the house. Larger single-storey extensions, up to 6 metres or 8 metres, can use the prior approval process, where the council notifies your neighbours. Side extensions and anything two storeys high are more restricted. Permitted development rights are more limited in conservation areas and don't apply to flats. Maidstone borough has 41 conservation areas. In the Holy Trinity Church conservation area, near the town centre, an Article 4 direction removes permitted development rights for most changes to the outside of a house, and parts of Headcorn, Lenham, Loose Valley and Hollingbourne have Article 4 directions too. If you're relying on permitted development, a Lawful Development Certificate from the council gives you proof for when you sell.

Every extension needs Building Regulations approval, whatever the planning route. This covers foundations, structure, insulation, drainage, fire safety and ventilation. You can use Maidstone Borough Council's building control service or a private approved inspector, and you'll need a completion certificate at the end.

Drains are a common surprise. Many terraces and semis have a shared sewer running under their back gardens, and since 2011 these belong to the water company, which in Maidstone is Southern Water. If you build over or close to a public sewer, you'll need Southern Water's approval before work starts. A CCTV drain survey or Southern Water's sewer records will show where the pipes run.

Two more local checks. The council has more than 1,000 tree preservation orders, so check before any tree near the footprint is touched. And if your home is near the Medway, the Len, the Loose or the Beult, check its flood risk on GOV.UK, as an extension in a flood zone may need a flood risk assessment with the planning application.

Steel beams to open up the back of the house need calculations from a structural engineer, and work on or near a shared wall will need a party wall notice to your neighbour. A single-storey extension usually takes three to four months on site. Allow extra time before that for design, approvals and ordering steel and glazing.

When comparing builders, give them all the same drawings and specification. Ask for itemised quotes with any provisional sums clearly marked, a written contract, a programme and staged payments tied to progress. Check their insurance and ask to see extensions they've finished. Reviews on Trade Pilot come from real, invoiced jobs.