Is It Worth Retrofitting a Motor to an Old Rooflight?
Retrofitting a motor to an old rooflight is rarely worth it. It only works on compatible ranges to begin with, and even where a kit fits, you are adding a new mechanism to a tired frame with hardened seals and dated controls, so you spend on the one part that will still be surrounded by everything that is worn. On a unit that is more than about ten years old, replacing the whole rooflight usually costs little more once you count the renewed seals, flashing and warranty, and it lasts far longer. The exception is a compatible, sound, fairly recent manual unit, where a solar conversion kit is a fair upgrade.
The compatibility limit
You cannot motorise just any rooflight. Retrofit kits, usually solar conversion kits, are made for specific current or recent ranges of manual roof window, and they mount to that unit’s frame and hinge geometry. If your unit is an older or discontinued range, there may be no kit that fits at all. The first question is always the make, model and generation, which is on the data plate on the top edge of the sash. Photograph it before planning anything, because it decides whether the conversation is even possible.
Why a tired frame rarely justifies the outlay
Say a kit does fit. The question then is whether the rest of the unit is worth building on, and on an old rooflight the answer is usually no.
- Hardened seals. A ten or fifteen-year-old gasket has gone hard and lost its compression. Adding a motor does nothing for the seal, so you can end up with a nicely motorised unit that still lets driven rain past.
- A tired frame. Old frames flex and their fixings loosen. A retrofit actuator pushing and pulling a frame that has lost its rigidity is not a recipe for a long, reliable life.
- Dated weathering. The flashing around an old unit is as old as the unit. Replacing the rooflight renews it; retrofitting a motor leaves it.
- No warranty on the outcome. You are combining a new kit with an old unit, and if it leaks or binds, the responsibility is muddy. A new unit carries a fresh manufacturer warranty and our 10-year workmanship guarantee.
The numbers, side by side
| Factor | Retrofit a motor | Replace the unit |
|---|---|---|
| Fits your unit? | Only compatible ranges | Always |
| Seals and gaskets | Left as they are | Renewed |
| Flashing and weathering | Left as it is | Renewed |
| Controls | New kit, but on an old frame | Current, supported system |
| Warranty | Muddy, mixed old and new | Fresh manufacturer and 10-year workmanship |
| Typical cost | £520 to £850 on a compatible unit | From £1,600 like-for-like |
| Sensible when | Sound, recent, compatible manual unit | Unit over about ten years old, or incompatible |
The honest split. A solar conversion kit on a sound, fairly recent, compatible manual unit is a genuine bargain, often the cheapest useful upgrade in the house at 520 to 850 pounds. A motor retrofit onto an old, tired or incompatible unit is money after a lost cause. The dividing line is the age and condition of the frame, not the price of the kit.
When the mechanism has already failed
This page is about adding a motor to a working manual unit. If your electric unit’s motor has already failed, that is a different question with a clearer answer: a seized actuator strains the frame and seals, and on an out-of-warranty, out-of-support unit we replace rather than repair. The reasoning is on the failed opening mechanism page. If it is the controls that have gone obsolete rather than the motor, the obsolete controls page covers why legacy parts strand otherwise-sound units.
If replacement is the answer
Replacing renews the seals, the flashing, the controls and the warranty in one go, and it is the moment to get the specification right: the actuator type, whether a rain sensor is worth heating for coastal fret, and whether a solar or mains unit suits the room. The whole decision is on the electric skylight installation page, and if you are weighing whether the replacement even needs to open, the electric versus manual rooflight comparison helps.
Common questions
Can I add a motor to my existing manual rooflight?
Only if it is a compatible range. Solar conversion kits are made for specific current or recent manual roof windows and mount to that unit’s frame, so an older or discontinued unit may have no kit that fits. Photograph the data plate on the top edge of the sash and send it with your enquiry, and we will tell you whether a kit exists for your unit before you plan anything.
Is it cheaper to motorise or replace?
On a sound, recent, compatible unit, a conversion kit at 520 to 850 pounds is cheaper and a genuine bargain. On an old unit with hardened seals and dated flashing, the kit is money spent on the one part surrounded by tired ones, and a replacement from 1,600 pounds usually gives far better value because it renews the seals, flashing, controls and warranty together. The dividing line is the age and condition of the frame.
Will retrofitting a motor stop my rooflight leaking?
No. A leak comes from hardened seals or tired flashing, and adding a motor does nothing for either. You could end up with a motorised unit that still lets driven rain past. If the unit is old enough to leak, it is old enough that replacing it, which renews the seals and weathering, is the better spend. A conversion kit is for adding convenience to a sound unit, not fixing a failing one.
Get an honest assessment
Send us a photo of the data plate on the sash edge and a note of the unit’s age and condition. We will tell you plainly whether a conversion kit fits and is worth it, or whether replacement is the better value, and give you one written price fixed after survey with a 10-year workmanship guarantee.
Request a fixed quote for a rooflight conversion or replacement across Ipswich, Suffolk and north Essex.
Thinking about this job? We survey across Ipswich, Suffolk and north Essex and give you a fixed price before any work starts, with a 10-year workmanship guarantee.