Can you put a lantern into a flat roof I already have?
Often yes, and it is one of the quickest ways to transform a dark back room. The two things we check first are what the flat roof is built from and what condition the covering is in, because cutting into a roof that is at the end of its life means you will be back doing the whole thing in two years. If the deck and covering are sound, forming the opening, building the upstand and fitting the lantern is normally a job of a few days.
Why do rooflights leak?
Nearly always because of how they were fitted rather than the unit itself. Upstands built too low, flashing dressed badly, the roof covering not carried up high enough, or a lantern set straight onto a deck with no kerb at all. Water finds every one of those. Getting it right is not complicated, it is just a job that has to be done in the right order by the people who also own the roof, which is exactly why we do both.
Bifolds or sliding doors, which is better?
It depends what you want from the opening. Bifolds give you the whole gap open, which is lovely on the handful of really warm days a year, but you get more frame in the view when they are shut. Sliders keep the glass cleaner and the view wider when closed, which is how you look at them for most of the year, and modern ones open plenty wide enough for most people. We will show you both on site against your actual opening rather than in a brochure.
Do I need permission for a rooflight?
On most houses rooflights fall under permitted development as long as they do not project more than a set distance from the roof plane and are not above the highest part of the roof. On the front elevation of a house in a conservation area it is a different conversation, and listed buildings are different again. It also needs building regulations for the structure and the glazing. We will check what applies to your house before anything is ordered.
How much light will a lantern actually add?
A lot more than the same area of glass in a wall, because a rooflight faces the whole sky rather than one direction. As a rule of thumb, glass in the roof does around two to three times the work of glass in a wall for daylight. That is why a deep kitchen extension with a lantern over the middle feels bright all day while the same room with only patio doors is dark at the back.
Can you fit glazing supplied by someone else?
Yes. If you have already bought a lantern or a set of bifolds we will form the opening, build the upstand or set the lintel, and fit them. What we will ask for is the manufacturer's sizes and details before we build the opening, because a kerb built to the wrong dimension is an expensive thing to discover on delivery day.
