Walsh Builders Ltd is an established and experienced local extension builder in NN6. Please contact us for a free, no obligation quote and competit...
From £86,688
Experienced extension builder ready to quote for your work. Reco life is the best extension builder in NN6. No obligation free quotes and many happ...

Building a granny annexe ranges from £86,688 (Reco life based in Nn6) to £86,864 (Walsh Builders Ltd based in NN2), but these are just estimates that can help give you an idea of who will be better value in your area.
The best thing to do is to get quotes to build a granny annexe in NN6 by posting a job with HaMuch. We will send it to extension builders in NN6 who will be happy to help you.
"Granny annexe" - NN5, job posted 08/04/26
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Granny Annexe near Northampton | £35 | £239 |
| Granny Annexe near Wellingborough | £39 | £251 |
| Granny Annexe near Kettering | £34 | £237 |
| Granny Annexe near Daventry | £31 | £230 |
| Granny Annexe near Market Harborough | £31 | £217 |
| Granny Annexe near Rugby | £31 | £224 |
| Granny Annexe near Rushden | £34 | £231 |
| Granny Annexe near Corby | £30 | £214 |
| Granny Annexe near Wigston | £28 | £209 |
| Granny Annexe near Milton Keynes | £39 | £263 |
Whether you’re looking to extend your kitchen with a side return extension or you want to convert your basement into a liveable space, read our cost guides to get an idea of how much each project costs before getting a more accurate quote from our database of reliable tradespeople.

Underpin a building - £17,276

Two storey extension - £87,664

Build a timber frame extension - £25,776

Build a swimming pool - £80,776

Single storey extension - £50,520

Side return extension - £38,980

Install an RSJ - £1,976

Outbuilding - £9,776

Build a Mansard loft conversion - £51,776

Loft conversion - £31,650

Build a kitchen extension - £41,776

Hip to gable loft conversion - £41,776

Granny annexe - £86,776

Garden office - £9,776

Convert a Garage - £15,776

Garage - £18,276

Build a flat roof extension - £21,776

Build a dormer loft conversion - £41,776

Concrete foundations - £6,026

Convert a bungalow loft - £28,776

Convert a basement - £34,980