Chelmsford · Essex
Roof Lanterns in Chelmsford
A roof lantern in Chelmsford can flood a dark extension or kitchen with daylight from above, and our glaziers check the roof and upstand before you receive a fixed written quote.
- CM1
- Guide from £1,095
Flat roof skylight in Chelmsford: what to know
A roof lantern is assembled from an aluminium ridge, hip bars and glazing bars that hold sealed glass units on each pitch. It sits on an upstand built around the roof opening. The upstand should be level, weathered into the roof covering and insulated, because a poor upstand causes most leaks and cold spots.
In England, a rooflight on a house is usually permitted development if it projects no more than 150mm beyond the roof plane and is no higher than the highest part of the roof. Raised lanterns often stand taller than that, so check with the council before ordering.
Glass for lanterns usually comes with a self-cleaning outer coating that helps rain wash away dirt, and a choice of clear, neutral or blue-tinted solar-control glass. Solar-control glass limits heat build-up under a south-facing lantern, while clear low-E glass suits shaded or north-facing rooms.
Roof lanterns are not designed to be walked on, so never stand or lean on the glass or bars. Cleaning and inspection should be done from safe access at the edge of the roof. Keep leaves and debris away from the upstand and roof outlets so water drains freely.
What a typical job includes
- Survey of the roof, opening, upstand and drainage
- Made-to-measure aluminium roof lantern or framed skylight
- Written guarantee terms and manufacturer documentation
- Sealed double glazed units with laminated inner pane options

Local details for Chelmsford
- Postcodes covered
- CM1 and the surrounding area, including Billericay, Witham and Maldon
- Coast
- Chelmsford sits roughly 16 km from the nearest coastline, close enough that exposure on open or high ground is worth considering. Coastal lanterns face salt deposits on the glass and frames and strong uplift from wind on exposed roofs. Marine-grade coatings, stainless fixings and secure fixing to a well-built upstand matter, and salt film may need rinsing more often than self-cleaning glass manages alone.
- Daylight and sun
- In Chelmsford the midwinter sun reaches about 15° above the horizon at noon, with roughly 7.6 hours of daylight, rising to about 62° and 16.4 hours in midsummer. Overhead glazing receives far more light than a wall window of the same size, especially when the sun is high in summer. South-facing lanterns may need solar-control glass, while low winter sun and north-facing rooms benefit from clear, high light-transmission low-E glass.
- Access and setting
- Getting a large lantern onto a terraced flat roof may mean carrying it through the house or lifting it over neighbouring property, so access is planned at survey. Lanterns near a boundary raise fire performance questions, and conservation areas may restrict raised glazing.
- Rules in England
- Approved Document K requires safety glass in critical locations in England: glazing in doors and in side panels within 300 mm of a door, up to 1500 mm above floor level, and any glazing in walls or partitions up to 800 mm above floor level.
Guide prices in Chelmsford
| Typical job | Guide price inc VAT |
|---|---|
| Lantern 1500 × 1000 mm, fitted to a kerb | £1,395 – £1,795 |
| Lantern 2000 × 1000 mm | £1,695 – £2,095 |
| Lantern 3000 × 1500 mm | £2,795 – £3,695 |
| Flat glass rooflight 1000 × 1000 mm | £1,095 – £1,395 |
Get a guide price for your size
In England, replacing a whole window, roof window or glazed external door is building work. It has to be notified to building control, either by an installer registered with a competent person scheme such as FENSA or Certass, or through a building notice to the council. Replacing only the glass in an existing frame is a repair and is not notifiable.
Options to choose between
Solar-control glass
Neutral or blue-tinted coatings that reduce heat build-up under south or west-facing lanterns while keeping daylight levels high.
Rectangular hipped lantern
A long ridge with hipped ends, suiting most rectangular extensions and kitchens, sized to the opening and the room below.
Flat framed skylight
A low-profile framed rooflight on a flat roof upstand, fixed or opening, for bathrooms, landings and smaller rooms.
Roof Lanterns in Chelmsford: questions
Should the inner glass in a roof lantern be laminated?
Laminated inner glass is the safer choice and is recommended by the Rooflight Association. If a laminated pane breaks, the interlayer holds the pieces together, so glass is far less likely to fall into the room below. This matters most over kitchens, dining tables, stairs and seating, and it is offered as a standard option.
Does fitting a roof lantern need building regulations approval?
A new roof lantern or skylight generally needs building regulations approval, because the roof structure is cut and must be supported, and the unit must meet energy standards. Fire performance also matters near a boundary. Replacing a lantern on an existing sound upstand is simpler, and we explain which route applies at survey.
Why does my roof lantern get condensation?
Condensation forms when warm, moist air from cooking, bathing or drying clothes meets the colder glass and frames at high level. Older single glazed or non thermally broken lanterns suffer most. Thermally broken frames, warm-edge spacers, extractor fans and opening vents reduce it. Some condensation on very cold mornings is normal and clears as the room warms.
Do I need planning permission for a roof lantern?
Sometimes. In England, rooflights on a house are usually permitted development if they project no more than 150mm above the roof plane and are no higher than the highest part of the roof. Raised lanterns often exceed that, and flats, listed buildings and conservation areas have extra controls, so check with your council first.
Do you cover Chelmsford for roof lanterns?
Yes. We can quote for roof lanterns across Chelmsford and the surrounding Essex area, including postcode districts CM1, and nearby Billericay, Witham and Maldon. Start with your postcode on the quote form and a glazier will arrange a free survey before giving you a written quote.
Get a written quote in Chelmsford
Free survey for new glazing, clear guide prices and one point of contact for every glazing job.