The 10 extension builders from Google's results for Oxford, ranked on Google rating, online presence and other factors. Updated 10 September 2026.
on GoogleSummertown, Oxford
Knights Builders Oxford provides a design-and-build service covering loft conversions, kitchen extensions, period property renovations, and new home builds. The firm serves clients across Oxford, Abingdon, Didcot, and the surrounding Oxfordshire areas.
07909 551826 Prama House, 267 Banbury Rd, Summertown, Oxford OX2 7HT
on GoogleDidcot
Oxon Conversions delivers construction services across Oxford and Oxfordshire. The company offers a complete design and build package that encompasses loft conversions, new house builds, home extensions, and property renovations.
01865 537403 Harwell Innovation Centre, 173 Curie Ave, Didcot OX11 0QG
on GoogleNewbury
Philip Wadge Architecture is a design studio drawing up new houses, barn conversions, extensions and renovations for homeowners across Oxfordshire and around Newbury. Its projects stretch from Henley-on-Thames to villages in the Chilterns, with each design shaped by the setting of the property.
01635 736440 Unit 4B Kingfisher Ct, Newbury RG14 5SJ
on GoogleYarnton, Kidlington
Clarus Construction provides house extensions and full property renovations across Yarnton, Kidlington, and Oxford. The team offers complete project management for domestic conversions and structural alterations designed to expand ground-floor accommodation.
01865 608518 31, Yarnton, Kidlington OX5 1NG
on GoogleOxford
Resonant Architecture delivers architectural design for two-storey house extensions, garden studios, and Grade II listed townhouses in Oxford. Projects range from timber extensions to community hall rebuilds and sustainable residential schemes.
01865 403235 The Old Music Hall, 106-108 Cowley Rd, Oxford OX4 1JE
on GoogleIslip, Kidlington
Planning and design for house extensions, loft conversions, and kitchen-dining additions are handled by Extension & Alterations, Headington, Oxford. Based in Islip, the firm updates older properties through two-storey side extensions and rear structural alterations.
07884 331216 North St, Islip, Kidlington OX5 2SQ
on GoogleCumnor, Oxford
Lynch Brother Homes delivers full building and decorating services across Cumnor and the Oxford region. The company undertakes new builds, house extensions, loft and garage conversions, kitchen and bathroom installations, alongside exterior rendering and redecoration.
01865 420063 Unit 2, Bradley Farm, Cumnor, Oxford OX2 9QU
Summertown, Oxford
Home Extensions Oxford constructs residential additions including new dining spaces, expanded kitchens, and additional bedrooms across Summertown and Oxford. The builder also carries out loft conversions to help clients increase internal living areas.
01865 339500 267, Prama House, Summertown, Oxford OX2 7HQ
Oxford
Specialising in rear, side return, and two-storey builds, House Extensions Oxford covers all stages from initial groundworks to final painting. Operating across the city, the division handles planning approvals and structural work for residential additions.
Oxford
Oxon Builders constructs single-room and two-storey additions for residential properties across Oxford. Its work centres on expanding existing living spaces as a practical alternative to moving home.
In Oxford, single storey, per m² typically costs £2,000 – £2,800. Labour in Oxfordshire runs 12% above the UK median, which accounts for most of the difference from the same job elsewhere.
These are the firms from Google's results for "house extensions oxford". They are ranked on Google rating, online presence and other factors.
The figures above are Oxford ranges. These explain what drives them, so you can read a quote properly.
Per-square-metre prices for single-storey, two-storey, side return and kitchen extensions, costs by size, the fees outside the build price, and planning limits by nation.
The permitted development limits for extensions, lofts, porches and outbuildings in England, where the rights do not apply, what prior approval and a certificate cost, and how Wales, Scotland and NI differ.
When the Party Wall Act applies, which notice to serve and how far ahead, what your neighbour can do, what a surveyor's award costs, and the rules in Scotland and NI.
Under permitted development, three metres for a terrace or semi and four for a detached, doubled to six and eight under the prior approval process. Height, materials and how much garden you cover all carry separate limits, and none of it applies in a conservation area.
If you are excavating within three metres of a neighbour's foundations or building on the boundary, yes. You must serve notice two months before work starts. Skipping it is the most common reason extension projects stall.