Do you have an upstairs room that is starved of natural light?
Have you considered the installation of a sun tunnel?
The sun tunnel increases the amount of natural light even on a cloudy day, the reflective surface of the tunnel make it as light inside your property as it is outside, meaning you may not need to turn on the light so often therefore reducing your energy bills.
One of the many advantages of fitting a sun tunnel rather than a roof light is that the flexibility of the tunnel between the roof and the ceiling allow you to have the tunnel fitted where you want it rather than being governed by where the timber structure of the roof is.
The most common areas to have a sun tunnel fitted are bathrooms, stairs and landings because they are traditionally areas which have a lack of natural light