We want a conservatory and does the maximum of 3m deep apply to internal or external size of the conservatory, my neighbour has a 3.5m deep one which he did not get planning permission for 8 years ago

Hi Anne we build 15 to 20 conservatories per year the planning issues are exact throughout the country. If you follow this link it will take you to your local planning portal which is a three dimensional simulation which will show you what you can and cannot do. www.planningportal.gov.uk As you live in a semi detached you will see on the portal that you can only go out three meters deep to external brick work unless you get planning. Your neighbour was lucky he did not get caught but unless a neighbour complains they will probably never know. Hope this helps. Many Thanks Barry Major Glass and Glazing

Hi Anne unfortunately when your neighbour had his conservatory built, different permitted development rules were in place to those that exist today. One of the factors was cubic volume created by all additions to the existing dwelling. Now it all depends on measurements and distances from boundaries. As per the answer above, the current rules are on the planning portal website. The 3m applies externally for planning permission. Your council are correct with the boundary issues, it's not that they won't help, it's more that they can't as there is nothing in the Town and Country Planning Act that allows them to get involved. It is a private civil issue. My suggestion would be to review the portal and see if you can find a conservatory that fits your needs that doesn't need permission. If this is possible for you I would also advise you apply for a "Lawful Development Certifictate for a proposed development" to your Council's planning team. The fee is £75 and will need drawings but it will give you a full legal document proving you didn't need to apply (this is extremely useful in disputes and property sales). regards paul

Give your local building control officer, via your local council, he will advise you what you can do, and get it in writing beforehand. Some councils are relaxed about sizes and some quite strict.