From £88,096
We are a Small Family run business with over 30 years experience in the building trade, Carpentry is my main trade, with NVQ Level 2.
From £87,144
We are a small family run business with over 20 years experience in brickwork, bathroom/kitchen fitting, roofing, landscaping, fencing, tiling and ...
From £86,992
Member since August 2026
H P Building Services Sussex is a one-stop solution for all your extension buildering needs. Establish over 10 years ago and covering 20 miles arou...
From £87,112
, BN18
Futureways Design and Build are here to help customers who need an Extension Builder in PO20. We offer a competitive rate to complete all your exte...
From £86,752
Park Building Services Ltd is a trusted extension builder serving customers in PO20 and the surrounding area. Contact us to today to get a competit...
From £87,440
Need to find an Extension Builder near you for all your extension buildering work?
Main Construction provides a local, trusted extension bu...
From £87,200
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £87,376
Giles Dixon is an experienced Project Manager with over 30 years experience, having worked from the ground up starting in 1984 as an apprentice ele...
From £87,128
Reliable and experienced extension builders with competitive rates and good at keeping within budget. Happy to provide examples of extension builde...
From £86,880
Trusted and professional extension builder in PO20. Experienced in all extension buildering work and keeping within budget and on quote. Stretch My...

Building a granny annexe ranges from £86,752 (Park Building Services Ltd based in PO9) to £88,096 (R&B Property Improvements based in PO9), 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 PO20 by posting a job with HaMuch. We will send it to extension builders in PO20 who will be happy to help you.
| Location in UK | Hourly Rate | Daily Rate |
|---|---|---|
| Granny Annexe near Chichester | £34 | £242 |
| Granny Annexe near Bognor Regis | £35 | £247 |
| Granny Annexe near Arun | £35 | £241 |
| Granny Annexe near Havant & Waterloo | £35 | £248 |
| Granny Annexe near Havant | £35 | £249 |
| Granny Annexe near Littlehampton | £35 | £244 |
| Granny Annexe near Rustington | £36 | £246 |
| Granny Annexe near Waterlooville | £36 | £250 |
| Granny Annexe near Horndean | £35 | £253 |
| Granny Annexe near Portsmouth | £36 | £250 |
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 - £17,712

Two storey extension - £88,318

Build a timber frame extension - £26,212

Build a swimming pool - £81,212

Single storey extension - £59,240

Side return extension - £43,885

Install an RSJ - £2,412

Outbuilding - £10,212

Build a Mansard loft conversion - £52,212

Loft conversion - £35,738

Build a kitchen extension - £42,212

Hip to gable loft conversion - £42,212

Granny annexe - £87,212

Garden office - £10,212

Convert a Garage - £16,212

Garage - £18,712

Build a flat roof extension - £22,212

Build a dormer loft conversion - £42,212

Concrete foundations - £6,462

Convert a bungalow loft - £29,212

Convert a basement - £39,885