House extensions in Warrington.

As a rough guide for Warrington and the surrounding area, a good-quality single-storey rear extension typically starts around £2,000–£2,500 per square metre. Double-storey works out lower per m² because you're getting more space for the same roof and foundations. We give you a proper fixed price after a site visit — no vague estimates.

Many extensions fall under Permitted Development, but limits vary by property type, size, boundary distances and whether you're in a conservation area or a listed building. We'll tell you honestly at the enquiry stage whether you need full planning, a lawful development certificate, or nothing at all — and can recommend a local architect if you don't already have one.

A single-storey rear extension is usually 10–14 weeks on site once foundations start. Double-storey and wrap-around extensions typically run 16–20 weeks. Kitchen fit-out and finishes tend to be the last stretch. We give you a proper programme up front so you can plan around it.

We work with a network of party wall surveyors and can point you to the right one if your project needs a Party Wall Award. We flag it early — long before you're mid-build with an unhappy neighbour.

For most rear and side extensions, yes. We seal the works off from the existing house wherever possible and time noisy phases so you're not caught out. For larger wrap-arounds or projects that involve the kitchen, we'll be upfront about the disruption and can help plan around it.

All our work is backed by ICW warranty cover where applicable, plus a workmanship guarantee direct from HJK. Manufacturer warranties (boilers, windows, roofs, etc.) pass through to you on handover.