Planning law regulates the way that property owners use and develop their property in the interests of the wider community. Local planning authorities are required to follow the national legal framework in their decision making. Planning law is often interwoven with other branches of the law, such as environmental, local government and judicial review. Clients might include landowners, developers, local authorities, public and private utilities, government departments, amenity groups and individuals.

Environment law seeks to protect both humans and the physical environment against pollution and the impact of human activity on the natural world. Environment lawyers find themselves involved in a wide range of matters, including health and safety risk management, contaminated land, waste, renewable energy, environmental finance, commercial and property transactions, and nuclear law.

Clare Parry is a barrister at 2-3 Gray's Inn Square. She read jurisprudence at the University of Oxford and, over the course of her degree and thanks to various mooting experiences, decided that she wanted to be an advocate. Clare felt a general inclination towards constitutional and administrative law: "I think academically it's interesting because it's connected with politics and the relationship between state and the individual." After her BVC at BPP in London, Clare secured a pupillage at 2-3 Gray's Inn Square.

"I saw quite a wide variety of work during pupillage," Clare recalls, "including lots of High Court judicial review and challenges. I saw some planning inquiries and some county court work. We always had a policy that if another member of chambers was doing something particularly interesting, you'd go and watch. For example, in my first month of pupillage our head of chambers was in the House of Lords, so all the pupils went along to watch. It was really interesting to see Anthony Scrivener QC in action, especially when you're so junior. The case was to do with people who had suffered from deep vein thrombosis. It was trying to see whether they could bring a claim under one of the treaties and regulations that apply to various aircraft. On the planning side, I saw quite a lot of fairly short planning enquiries, maybe one or two days long each. They're a useful exercise at that time because if you sit on a six-week planning enquiry as a very junior person, you can get lost. The one-day enquiries tend to be on less controversial issues - although I do remember quite a few people attending and barracking the barristers!"

Clare has recently been seeing an increasing amount of planning cases, including some High Court and advisory work. But she maintains a varied practice which includes housing and immigration. She gives us an idea of the kind of work she does that relates to planning: "At the junior end you tend to do a lot of enforcement appeals, which is where somebody's already built something without planning permission and you're having a discussion about whether they ought to remove it. Then there are issues to do with listed buildings which often tie in with planning permission. I once did an entire day's case about a dormer winder on a planning permission issue and a listed buildings issue. But that was unusual; I don't spend my days arguing abut dormer windows! Normally a case like that takes an hour."

Clare also highlights a three-week inquiry on behalf of some local residents in Wales. "It was in relation to some reservoirs near Cardiff that the council wanted to drain partly to build some houses. Another member of chambers was working for the council, so I was on the residents' side in the inquiry as they prepared the evidence. We reviewed that, discussed tactics and decided which bits of evidence were useful and which were not. In the inquiry itself we took the witnesses' statements, cross-examined the witnesses on the other side and made opening and closing statements - classic advocacy."

Clare says that she's in court three to four times a week, but it never intimidates her. "Personally I don't find it scary - I just really enjoy it. It's one of those things that you know whether you can do. If you go to court and want to be up there explaining everything, then you should be an advocate; whereas if you're glad it's not you then it won't be for you. I just think you know whether you want to be the person in the firing line."

She adds: "It's wonderful to win, particularly if it's a case that you've had concerns about or have advised the client there may be problems. It's very exciting in cases where you've had a lot of involvement yourself and suggested various bits of evidence and then the judge agrees with your analysis of the case. It's particularly enjoyable when the client's really pleased with the result."

But a lot of hard work goes on behind the scenes in order to achieve that kind of result. "You need good attention to detail," she counsels. "Lots of cases come down to specific points. You have to be quite good at picking up an area of law quite quickly and not being afraid of tackling an area of law you've never dealt with before - there's a lot of overlap and you increasingly find that the principles hold good even if there's a lot of difference in the detail."

Clare has solid advice for budding barristers - she sits on the pupillage committee at 2-3 Gray's Inn Square. "The key thing is to do some mini-pupillages in appropriate sets," she says. Clare did several mini-pupillages herself, mainly in planning and environment, but also in a general common law set. "They differ a lot in the sense that it depends on what's going on the week you happen to be there. But I think that the totality of them was very useful. I did three or four and so I saw a range of work, from what I might be doing in 15 years' time to what I might be doing as soon as I was taken on. That's very helpful because you need to see which bits interest you and keep you going at 10:00pm on a Sunday night!"

Clare insists that applicants must also be able to show academic ability or be able to explain why it's not on their CV. "It is an intellectual job," she says, "and unless you've got a good degree from a good university, I would want to see an explanation." Clare's final piece of advice is to understand truly that the hours a barrister works can be very demanding. "When you're a student it's easy to read that the hours are long, but it's different when you're working at 10:00pm on a Sunday night again!"