If you are planning a loft conversion or replacing a tired old Velux that has started to drip, this is the page for you. We are JD Home Improvements, a family run roofing team in Shirehampton, and we fit and flash roof windows across Bristol and the towns nearby. Here we explain the types, how they work with loft conversions, what makes an installation watertight, and how to get yours in without a leak.
Types of roof window
First, a quick word on names. Velux is a brand, the best-known maker of roof windows, so people often say "a Velux" when they mean any roof window. Skylight and rooflight mean the same thing too. Whatever you call them, there are three main types, and the right one depends on your roof and the room below.
| Type | Best for | Light |
|---|---|---|
| Pitched roof window | Lofts, conversions, any sloped roof | Lots, and opens for fresh air |
| Flat roof rooflight | Extensions, dormers, flat roofs | Bright overhead light |
| Sun tunnel | Dark landings, hallways, bathrooms | Soft daylight into windowless spaces |
Pitched roof windows
These are the classic roof windows set into a sloping roof, the ones you picture in a loft bedroom. They flood a room with daylight and come in a range of sizes to suit the space and the view. For most lofts and conversions, this is the window of choice.
Flat roof rooflights
Where the roof is flat, over an extension or a dormer, a flat rooflight brings light straight down from above. They look crisp and modern and pair naturally with the systems on our flat roofing page. A single well-placed rooflight can transform a kitchen-diner.
Sun tunnels
A sun tunnel is a clever fix for a windowless space. A small dome on the roof funnels daylight down a reflective tube into a dark landing or bathroom. It will not open, but it brings surprising brightness to a spot that would otherwise need the light on all day.
Roof windows and loft conversions
If you are converting a loft, roof windows are usually what make the new room liveable, and getting them in is as much a roofing job as a building one. Our part is the roof side: fitting the window and flashing it so it stays watertight for good. On a full conversion we work alongside your builder, who handles the structural and internal work, while we make sure the roof is sound and the windows are in properly.
Where a conversion includes a dormer, that dormer needs roofing too, often a small flat or pitched roof of its own. We take care of that side so the whole thing ties in with the rest of the house rather than looking bolted on.
What makes a watertight installation
Here is the detail that matters most, and the one cheap jobs get wrong. A roof window is only as good as its flashing. Every window comes with a flashing kit, and there is a different kit depending on whether your roof is tiled or slate. Fit the right kit correctly and the window sheds water perfectly for decades. Fit the wrong one, or rush it, and you get a slow leak that shows up as a stain months later.
Opening the roof matters too. The hole has to be cut cleanly, and where a rafter sits in the way it may need trimming, which on anything beyond a standard window size is where a structural check comes in. We size the opening properly and leave the inside reveal ready for your plasterer. Done right, the only sign of the work is the daylight pouring in.
Roof windows on Bristol homes
Bristol loves a loft conversion, and it is easy to see why. With space at a premium across the city's tall Victorian and Edwardian terraces in Bedminster, Bishopston, Southville and Totterdown, going up into the roof adds a bedroom or a study without losing the garden. Roof windows and dormers are everywhere as a result.
Suburban homes around Downend and Bradley Stoke take rooflights too, often in a kitchen extension to pull light into the middle of the house. Wherever the home, the same rule holds: the window has to be flashed to suit that particular roof, and our varied local housing keeps us working across every tile and slate type going.
Planning and conservation areas
A common worry is whether you need permission, so here is the plain version. On most homes, roof windows that sit in line with the roof slope on a rear or side roof count as permitted development, which means no planning application. That said, front-facing roofs and conservation areas such as parts of Clifton can need permission or a particular style of window.
In conservation settings, a conservation rooflight that sits flush with the roof keeps the traditional look the rules are there to protect. We will point you in the right direction on all of this, though the final planning check rests with you or your architect. Better to know before the work than after.
Replacing a tired or leaking roof window
Roof windows do not last forever. Older units can leak around perished seals or mist up as the sealed glass fails. Swapping an old window for a modern one usually cures a stubborn leak and brings a big jump in warmth and quiet into the bargain. If an old Velux has started marking the ceiling, we handle it under our roof repairs and can replace it with a current model that fits the same opening.
How we fit a roof window, step by step
We keep the whole job clean and watertight:
- We visit and advise. We look at the roof and the room, then suggest the best type and position.
- We quote in writing. A clear, itemised, no-obligation price.
- We set up access. Scaffold or proper access so the work is safe and tidy.
- We open the roof. The opening is cut cleanly and any rafter is trimmed where needed.
- We fit the window. With the correct flashing kit for your tiles or slate, sealed to shed water.
- We make good outside. The roof is finished neatly around the window and left watertight.
- We check and guarantee. A final inspection and our workmanship warranty.
What affects the cost
We price every job after seeing it, so be wary of a figure given over the phone. The main factors are:
- The window. Size and brand both matter.
- Your roof type. Each roof covering needs its own flashing kit.
- How many. A pair or a row works out differently from a single window.
- Access. Height and position decide the scaffold needed.
Our quotes are free and come with no obligation. You can request a free quote and we will come and look.
How to choose an installer
A roof window lives or dies on the flashing, so choose a roofer who treats it as roofing, not glazing:
- Proper accreditation. We are registered with the Confederation of Roofing Contractors (CORC) and our team holds CSCS cards.
- The right flashing kit, fitted right. Ask how they will flash it to your roof. We match the kit to your tiles or slate.
- A written quote after a visit. Never a price guessed from a photo.
- A proper guarantee. We stand behind the work.
- Local and accountable. We are based in Shirehampton, and you only pay once the job is finished to your satisfaction.
If a roof window ever lets water in during a storm, we also offer fast call-outs for sudden leaks.
Areas we cover
We fit and replace roof windows and rooflights across Bristol and the surrounding towns. Loft conversions on the terraces of Southville keep us busy, as do the Victorian villas of Redland, where steep slate roofs leave plenty of room for a loft bedroom. Give us a ring if you are unsure whether we cover your area.
Velux and skylight FAQs
What is the difference between a Velux and a skylight?
Velux is a brand of roof window, and skylight or rooflight is the general term for the same thing. People often say "a Velux" to mean any roof window. We fit all the main makes.
Do I need planning permission for a roof window?
On most homes, a roof window in line with a rear or side slope is permitted development and needs no application. Front roofs and listed buildings can be different, and we will point you the right way.
Can you fit roof windows as part of a loft conversion?
Yes. We handle the roofing side, fitting and flashing the windows, working alongside your builder on the structural and internal work.
My old Velux leaks, can you fix or replace it?
Usually both are possible. A perished seal can sometimes be repaired, but an old or misted window is often best swapped for a modern one that fits the same opening.
Can I put a rooflight in a flat roof?
Yes. Flat rooflights are a great way to light an extension or a dormer, and we fit them as part of our flat roofing work.
Will a roof window cause condensation?
Not when it is fitted and ventilated properly. A good installation and a little airflow keep the glass clear.
How long does it take to fit a roof window?
A single window is often a day's work once access is set up. More windows or a dormer take longer, and we give you a timescale in the quote.
Can a roof window go into a slate roof?
Yes. Slate needs its own flashing kit, and we fit it so the slates sit neatly around the window frame. The finished window stays watertight and looks tidy from outside.
Let us bring some light in
The right roof window turns a dark, forgotten space into somewhere you want to be, and the difference between a good job and a leaky one is all in the roofing. Whether you are converting a loft or replacing a tired old Velux, we will fit it properly and leave it watertight. Browse our other roofing services, or get in touch and we will come and take a look.