Flat rooflights in Grantham: what is involved?
Thinking about flat rooflights in Grantham? The short answer: fixed double or triple glazed rooflights for flat roofs and extensions. The longer answer depends on your roof, which is why we survey before we price.
Many Midlands semis have had a single-storey rear extension added, and a larger flat rooflight or lantern is often the change that makes it feel finished. Typical uses for flat rooflights include kitchen extensions, side returns and flat-roofed back rooms.
Grantham sits about 21 km from Newark-on-Trent and 23 km from Melton Mowbray, and we cover the whole NG31 postcode district and the roads in between.
Options we can specify in Grantham
- Solar-control or self-cleaning outer pane
- Integral or fitted blinds
- Double or triple glazing
- Frame colours: anthracite, black, white or RAL
- Plastered or lined internal reveal
- Double or triple glazed with a warm-edge spacer
- Pairs with an opening unit where you also need ventilation
Before you order: points to check
- Needs a properly formed upstand — usually at least 150 mm above the finished roof surface (check the manufacturer's figure)
- New openings in an existing roof need a structural check on joists
Planning, building control and Grantham
Most rooflights on English houses do not need planning permission, provided they keep within 150 mm of the roof surface and below the ridge line. A rooflight on a side-facing slope must be obscure-glazed, and fixed shut unless the opening part is more than 1.7 m above the floor.
Building Regulations Approved Document L sets a limiting U-value of 2.2 W/m²K for new or replacement rooflights in existing homes, measured in the horizontal plane; roof windows need 1.4 W/m²K or a Band B energy rating. In an extension, glazing including rooflights is normally limited to 25% of the new floor area plus any windows or doors the extension covers, unless a whole-house calculation shows otherwise.
See our building regulations guide for U-values, glazing limits and self-certification.
Flat rooflights prices in Grantham
Prices below are shown including and excluding VAT. In Grantham, as elsewhere, making good inside and access equipment are the main variables.
| Option | Guide price inc VAT | Ex VAT |
|---|---|---|
| Large or triple glazed (1500 × 2500 mm and up) | £2,395 – £4,195 | £1,995 – £3,495 |
| Mid-size double glazed (1000 × 2000 mm) Typical | £1,675 – £2,395 | £1,395 – £1,995 |
| Small double glazed (up to 1000 × 1000 mm) | £1,195 – £1,795 | £995 – £1,495 |
From enquiry to finished job
- Send the details. Postcode, rough size and a photo of the roof and room.
- Free site visit. For new installs we survey free, measure and confirm the roof detail.
- Agree the quote. You approve the specification and price before anything is ordered.
- Fitting and handover. We install, clean down and leave product and warranty documents.
Nearby towns
More we do in Grantham
Questions about flat rooflights in Grantham
Can you fit into my existing flat roof?
Yes. We form a new opening, trim the joists, build and waterproof an upstand and make good the ceiling. A survey confirms the joist direction and roof build-up first.
Can a flat rooflight be walked on?
Not unless it is designed as a walk-on unit with structural laminated glass. A standard flat rooflight is for light only — if the roof is used as a terrace, choose a walk-on rooflight instead.
Will it make the room too hot?
A big unglazed-to-sky area can add solar gain in summer. Solar-control glass, a blind, or pairing a fixed unit with an opening one keeps it comfortable.
Will I need planning permission in Grantham?
In England a rooflight on a house is usually permitted development under Class C if it projects no more than 150 mm beyond the roof slope and sits no higher than the ridge.
Can you work alongside my builder in Grantham?
Yes. On new extensions we fit once the opening and upstand are ready and coordinate dates with your builder.
