Indoor growing ranges from the very small scale - a few pots on a window sill (herb and pea shoots etc if its shady, or tomatoes, chillis etc on a sunny sill), to traditional greenhouses and polytunnels which increase productivity significantly, up to systems like hydroponics and biosperics..
Greenhouses and polytunnels
Build a plastic bottle greenhouse http://www.reapscotland.org.uk/wp-content/uploads/2011/04/Plastic_Bottle_Greenhouse_Instructions_2004.pdf
Greenhouse from old windows http://www.inspirationgreen.com/greenhouses-made-from-old-windows-and-doors.html
Growing in a greenhouse http://apps.rhs.org.uk/advicesearch/Profile.aspx?pid=613
Beginners tips for greenhouse growing http://www.realmensow.co.uk/?p=2838
See Shopping and Sharing for more on this topic
Advanced indoor systems
There are also a number of new technical systems which may suit the more adventurous grower, including hydroponics and aquaponics (which can also be carried out outdoors).
This is essentially growing in water, not soil or compost. Feed Leeds occasionally has access to equipment which is available free to gardeners
Aquaponics goes one stage further than hydroponics. The water tank contains fish which fertilise the plants, and can themselves be harvested.
Aeroponics goes one stage further than aquaponics - growing plants in a misted environment without any growing medium
Biospherics is, ideally, a complete, closed growing system.
Biospherics Foundation, Salford http://www.biosphericfoundation.com/projects/production/
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