Writing For Radio

The BBC is the main buyer for radio drama, possibly in the world. Before you even start to think about writing for them, listen to as much as you can. They have about two weeks of previously broadcast plays and stories on available to listen to online. The range is diverse as is the subject matter.
Google "Writing for Radio" for some great websites.

Hints:
Build the setting in the listeners head. Use of sound effects can be very effective here. Remember, there is no limitation on where the action can take place. Outer space, a 15th century chateau, The Pyramids, The North Pole, The Trenches, etc.
Music is a great way to get listeners into the mood.
Interior thought is easy to do on the radio compared to, for example, TV or stage. What people say and do and what they actually think are often in conflict so this can be a great tool to use to get inside a character's head.
A radio play only has one chance to be successful. If their attention is not grabbed and held, the listener can change channels at the click of a button. The beginning is everything as far as this is concerned.
Limit the number of characters so as not to confuse the listener. Make each one distinct for the same reason. Use their names in speech more often.
Keep the listeners on their toes by having one short scene after another. Use lots of mini crises and conflicts for cliff-hangers. Use humour too so the tension isn't continuous. Use sound effects to set each scene and don't have consecutive scenes in the same setting. Generally, don't have the last character in one scene being the first one in the next to talk.

Here is some good advice on writing for the 45 minute afternoon play slot. This London-based Theatre writer discusses finding the right producer, which I had never considered before. Otherwise, submit full script to The Writers Room.

The producers look for a writer with some experience, though this need not necessarily be in radio. They also look for a great one or two sentence blurb for them to use to sell the play to the commissioners.

Afternoon Play
45 minutes
14:15-15:00 Monday to Friday
This slots comes right after "The Archers" so I would tend to stay clear of similar, rural type stories and remember the audience demographic. Violence and graphic sex won't go down well. They say "First and foremost we want to tell the listener a good story." Crime, mystery, ghost stories, romance, historical, science fiction have all worked well in this slot. They do use new writers quite a lot for here.
Recent topics include, infertility, London in the 60's, mourning Princess Diana, the feelings of the land over the centuries and burying someone's ashes by the Angel of the North.

Saturday Play
60 minutes
14:30 Saturday
The home of genre fiction: Crime and detective stories, mystery, ghost stories, romance, thrillers. Not an extended afternoon play. Popular high class entertainment. Enjoyment and escapism. Think When "Harry Met Sally," "Gosford Park," "Lock, Stock and Two Smoking Barrells," "Into the West."
Recent topics include a dramatisation of the story that was the basis for the film Vertigo and Noel Coward persuading Ian Fleming to spy during the war.

Women's Hour
15 minute serial
10:45 repeated 19:45 5 consecutive weekdays
Study the market for this one. It's tricky to write something that picks up the story easily 5 times for listeners who don't tune in every day so I wouldn't recommend starting here. They often use serialisations of existing novels or biographies. Recent Topics include an affair between a teenage girl and an older son of a wealthy Chinese family and a farce about ladies involved in local action groups.

Comedy Narrative
30 minutes
11:30 Friday
Light and entertaining comedy drama or sitcom.
Recent topics include a comedy drama set in a Carmelite monastery.

The Friday Play
60 minutes
Friday 21:00
Original, contemporary and ambituous writing. Engaging and challenging.
Recent topics include an amnesty of illegal immigrants and teenage crime.

Afternoon Reading
15 minutes
Monday to Friday 15:30
A short story or abridged book often by writers new to radio.
Recent topics include waiting for a light effect, music heals war-damaged people, post operative surgery insights and a mouse looking for enlightenment from a parrot.

Here is a link to the radio play format. One page per minute in this format.