Help / advice with fig tree

I have a fig tree which is about 10 years old. Its in the kitchen with loads of light, I dont overwater it and there are no draughts and yet the leaf coverage is very very poor. What can I do to increase and improve leaf growth?
any help appreciated...

 

Is it a house plant type fig ie weeping fig, rubber plant type plant. I assume its not the plant we get figs from.

 

no its a ficus benjamina or something like that. Tall plant with (usually) lots of bright green leaves. Every other one I;ve seen look so much healthier than mine..

 

Ficus Benjamina is sometimes called the 'weeping fig'.
10 years, has it been repotted at all? How tall is it?

 

Its about 5 ft tall I repotted about 4 years ago. If it needs it again would this inhibit leaf growth?

 

Well it could. But growth would probably not be taking place at the moment anyway, due to the time of the year.
I reckon its probably pot bound, and next month a repot, a couple of inches bigger would do it the world of good. Then after six weeks or so feed it regularly.
You could prune any straggly growth back now but dont go mad, it will bleed white sap for a while,but this will stop.