house extension

[northantsman]

is there a maximum size to the extension I could build onto my house(percentage?) or will any size be considered when applying for planning permission?

[ajwt2]

# A detached / semi detached house can add up to 70 cubic metres or 15% of the un-extended house volume up to a maximum of 115 cubic metres

# A terraced property can add up to 50 cubic metres or 10% of the un-extended house volume up to a maximum of 115 cubic metres

http://www.whatprice.co.uk/conservatory/conser vatory-planning-permission.html

[rhona_j]

The council may also have a guideline that states the percentage of garden that must be left after the extension is constructed. This ensures that you don't build something the full size of the garden.
Check with your council's planning department to be sure.

[thundercrack]

if the other answers are correct, why is it that my next door neighbour got permission to build an extension to his bungalow that was actually larger than the original bungalow? also, I have seen lots of farm type cottage buildings that have extensions(not conservatorys) as large as the original house? is it different planning areas and not a general thing the country over?