Condensation between panes and fogged-up seals can leave your home feeling cold, damp and uncomfortable, and your heating bills climbing every month.
We replace tired, failing glazing with thermally optimised double-glazed units, fitted by FENSA-registered installers, with a free home survey and a 10-year guarantee for complete peace of mind. Our made-to-measure windows and rooflights use low‑E, argon‑filled units with certified U-values, warm-edge spacers and insulated frames to keep more heat in and draughts out. Every installation includes correct flashings, vapour control and advice on ventilation to reduce the risk of condensation.
Whether you are upgrading old windows or planning loft conversions and extensions in Manchester, we’ll help you choose the right size, glazing and shading for comfort all year round.
Read on to see how our double glazing service works, what it costs and what to expect from installation.
Takeaways
- A‑rated double or triple glazing with argon and low‑E glass slashes heat loss and heating bills.
- Frames with verified whole‑window U‑values and psi‑values to EN/ISO standards deliver predictable energy performance.
- Thermally broken aluminium, reinforced uPVC or factory‑finished timber with continuous gaskets boosts airtightness and comfort.
- Insulated upstands, warm‑edge spacers and sealed vapour barriers prevent cold bridges, damp patches and costly condensation damage.
- Correct SHGC, roof pitch and multiple smaller rooflights reduce summer overheating while keeping rooms bright and usable.
Thermally Efficient Skylights: Choose the Right Option
Pick a skylight on its figures, not just how it looks. Ask for the U‑value, solar heat gain coefficient (SHGC) and visible light transmission on the quote, and make sure they’re based on a tested 28mm argon‑filled unit with a soft‑coat low‑E glass, not a guess off a brochure.
Glazing build makes a big difference. A double‑glazed, argon‑filled, low‑E unit with warm‑edge spacer will usually sit around A‑rated performance, cutting heat loss through the roof far better than an old single pane. Triple glazing can bring U‑values down further, but it adds weight, so the roof structure and opening gear need checking.
Frame material matters as much as the glass.
- Aluminium needs a proper thermal break and decent gaskets or it will pull heat out and cause condensation.
- uPVC gives good insulation and is low maintenance if it’s steel‑reinforced and sealed with a Q‑LON gasket.
- Timber works well thermally if it’s factory finished and the external cappings are correctly flashed.
Match the SHGC to the roof pitch and direction. On south‑facing slopes in the UK, a lower SHGC glass helps cut summer overheating. On north‑facing areas, a slightly higher SHGC can help you gain free heat without glare if the visible light figure is still good.
Check details that affect draughts and damp, not just U‑values. The skylight should have tested airtightness, decent drainage channels and a frame design that resists internal condensation around the edges of the unit. Properly packed and foamed reveals, with vapour‑tight tapes, stop cold spots and mould forming.
Installation is where a lot of performance is lost. The price should allow for:
- Correct flashing kit matched to your roofing material
- Insulation brought tight to the frame, not left with gaps
- Internal trims sealed and caulked, not just pushed in dry
Cheap fittings, weak hinges and light‑duty opening gear will sag or leak and wipe out the benefit of the A‑rated glass. Ask for the skylight’s certified test data on the paperwork and have the installation sequence written into the contract, so the unit that goes into your roof in, say, Manchester actually performs like the one on the certificate. A FENSA certificate number on completion confirms it’s been fitted to current Part L standards.
Skylight Types Compared: Pitched, Flat, Tubular, Fixed, Ventilated
All skylights bring in natural light, but the frame design and how they open make a big difference to heat loss, condensation and how they sit on your roof.
Pitched skylights are built for sloped roofs and work well with proper lead or aluminium flashing kits. With a 28mm argon-filled, low‑E double-glazed unit and continuous insulation around the frame, you get steady thermal performance, better condensation control and good noise reduction, especially with laminated or acoustic glass.
Flat rooflights suit low‑pitch or flat roofs but must be fitted on a correctly sized, insulated upstand to keep the 28mm sealed unit above standing water and stop cold bridging. Good drainage detailing and a continuous Q‑LON gasket around the sash keep draughts and leaks out.
Tubular skylights are useful where you can’t alter the roof much or space is tight. A small weathered roof dome feeds light down a reflective tube to a ceiling diffuser, so you only need a modest opening and minimal trimming to the rafters, but the light spread is limited and not suitable for larger rooms.
Fixed skylights don’t open, so there are fewer moving parts and less to go wrong. With internally beaded frames, A‑rated glass and fully sealed corners, they’re secure, low‑maintenance and hold their U‑values well.
Ventilated skylights open on hinges or electric actuators to let out warm, moist air from kitchens, bathrooms and lofts. To keep within conservation and acoustic requirements in areas like older parts of town, we use slimline profiles, trickle vents where allowed, multi‑point locking and tight compression seals tested for air and water tightness, then register the job with FENSA and issue your certificate number on completion.
Glazing & Frame Specs: U‑Value, SHGC, Low‑E and Spacer Bars
Glazing and frame specs are what actually decide how warm your house feels and how much you spend on heating, not whatever’s on the sales leaflet. Treat U‑values and SHGC (solar gain) figures as hard limits, same as you would a boiler output or cavity width. For most homes we aim for an A‑rated, argon‑filled 28mm sealed unit with a low‑E coating, keeping the U‑value down for winter while using the right solar gain to make use of free heat from the sun.
Any decent manufacturer should give you certified centre‑of‑glass and whole‑window U‑values, tested to EN and ISO standards, not guessed. We match the glass spec to the opening: south‑facing rooms might get slightly lower solar gain to stop them overheating; north‑facing windows can take a higher gain unit so you keep as much heat as possible.
We normally specify:
- Double or triple glazing with soft‑coat low‑E glass
- Argon‑filled units with 16mm cavities where the frame allows
- Warm‑edge spacer bars to cut down cold bridging at the glass edge
Warm‑edge spacer bars and a good Q‑LON gasket make a big difference to draughts and condensation round the frame. Stainless or thermally broken aluminium frames still need proper thermal breaks or insulating cores, otherwise the frame becomes the cold spot instead of the glass.
On every job in and around Manchester we check frame psi‑values, cavity widths and gas fills, and we only fit units with fully certified edge seals. You get a FENSA certificate number on completion, and we specify glass and frame systems that come with long‑term performance warranties, so the U‑values you paid for are still there years down the line.
Placement, Size and Shading to Maximise Daylight and Avoid Overheating
You get the best from a skylight when the glass and frame are right, and the size and position suit the room. With a decent A-rated, argon-filled, low‑E unit in a thermally broken frame, the next step is to plan where it goes so you gain daylight without the room boiling in summer.
On most homes we fit larger rooflights on the north‑facing pitches for a steady, glare‑free light. On east and west slopes we usually keep the glazed area tighter, as the low sun first thing and late afternoon can cause glare and unwanted heat gain.
We size the opening based on room depth and the daylight level you actually need, not a guess. For bigger jobs we’ll run basic daylight calculations or work from your plans so the skylight is doing its job without being oversized.
To control summer overheating, we allow for shading at the design stage. That might be:
- Fixed external overhangs or kerbs that block high summer sun
- External blinds or shutters
- Automated roof blinds on difficult‑to‑reach units
Several smaller, made‑to‑measure openings usually work better than one large pane, spreading the light, cutting down hot spots and helping cross‑ventilation if some are opening lights with trickle vents and secure night‑vent positions.
We always try to deal with excess heat outside the glass first, using external shading where possible. Glass coatings on the 28mm sealed units help, but on their own they’re no substitute for proper shading and good frame detailing with continuous Q‑LON gaskets to keep things airtight and controlled.
Installation, Insulation and Ventilation to Meet Regs and Save Energy
Getting a skylight right isn’t just about the glass spec. The way it’s fitted into the roof makes the difference between an A‑rated unit saving you money, or leaking heat and causing damp. We install every skylight as part of the roof’s thermal envelope, not as a bolt-on.
We run the loft insulation tight up to the upstand or kerb so you don’t get cold patches around the opening. Joints at rafters and abutments are packed and taped to stop thermal bridging, and we use a continuous vapour control layer, sealed directly to the skylight frame, for proper airtightness.
On most jobs we recommend insulated upstands that help you hit current U‑value targets and cut draughts around the frame. The skylight units themselves are usually 28mm argon‑filled, low‑E double glazing, so there’s no point leaving bare timber around them to leak heat.
Ventilation is planned to suit the room. In kitchens, bathrooms and loft conversions we’ll allow for:
- Trickle vents in the skylight frame for background ventilation
- Mechanical extract if required by Building Regulations for moisture control
We check condensation risk on site, not just on the drawings. On completion you get the FENSA certificate number on your paperwork, along with the glass spec and installation details, so you can prove compliance and know exactly what’s been fitted in your home in Leeds.
Frequently Asked Questions
Do Skylights Increase Home Insurance Premiums?
They can push premiums up a bit, but not in every case. Insurers tend to look at the extra risk of leaks, storm damage and glass breakage, and may add a higher excess for roof glazing. If the skylight’s professionally fitted with approved, toughened or laminated glass and you tell your insurer, it usually keeps things straightforward.
Can Skylights Be Retrofitted Into Tiled Roofs Without Structural Changes?
Yes, in most cases we can fit skylights into a tiled roof without altering the main structure. We cut between the rafters, add the correct support timbers, then use manufacturer-specific tile flashings so it stays watertight and ventilated. A good roofer or FENSA-registered installer will check rafter spacing and load before you go ahead.
Are There Skylights Compatible With Solar Panels or Integrated PV?
Yes, you can get skylights that work with solar panels and integrated PV. We’d use a rooflight system with solar-ready glazing, so the PV laminate or micro-modules sit on or in the glass without affecting the weather seals or U-values. Your electrician would handle wiring routes and inverter position, and we’d confirm loading, fire rating and warranty with the manufacturer.
How Do Skylights Affect Indoor Acoustics and Noise From Rain?
Skylights can make rain sound louder if they’re thin single-glazed or poorly sealed, a bit like a drum. If you go for laminated double or triple glazing, 28mm argon-filled units and good insulated frames, the rain noise is much more muted. Ask for tested Rw sound ratings and proper acoustic seals during installation for the best result.
What Maintenance Schedule and Costs Should I Expect Over 20 Years?
You’re looking at a quick check and clean once a year, with the sealant around the frames usually needing redoing every 8–15 years. A yearly visit lets us spot failed 28mm sealed units, condensation between panes or corroding flashing early; budget roughly £50–£150 a year, £150–£500 for resealing, and maybe £500–£2,000 over 20 years for any bigger repairs or replacement glass.