Velux windows and rooflights supplied and fitted across Northampton. New installations, replacements and sealed unit repairs — correct flashing kits, 10-year guarantee.
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Velux and rooflight installation is one of the fastest-growing areas of our work in Northampton — driven by loft conversion activity on 1930s semis and post-war stock, and the large number of existing units now reaching the age where sealed units and flashings need attention.
Northampton's housing lends itself to Velux installation. The 1930s semis throughout Abington, Kingsthorpe and Duston have roof pitches and rafter spans that accommodate standard Velux sizes without structural alteration in most cases. The post-war semis on Blackthorn and Rectory Farm offer similarly straightforward installation conditions.
Installation is only half the job. The flashing kit — the lead and aluminium collar that makes the junction between the frame and surrounding tiles weathertight — must be specified to the correct tile profile and correctly dressed. Flashing failures are the most common source of Velux-related leaks, almost always the result of using the wrong kit for the tile or cutting corners on the dressing. We specify EDW or BDX flashing kits by tile profile as standard.
For existing Velux units, we replace failed sealed units (the double-glazed pane), repair or replace corroded flashings, and replace complete windows where frames have deteriorated. Sealed unit replacement is a cost-effective alternative to full window replacement where the frame is still sound.
📞 Free quotes — no call-out fees across Northampton
Call 0160 428 1189Velux and rooflight installation in Northampton includes supply-and-fit, sealed unit replacement and flashing repair. A standard Velux fitted costs £600–£1,200; sealed unit replacement £200–£400. We specify the correct flashing kit for your tile profile. Free no-obligation surveys on 0160 428 1189.
A well-fitted rooflight transforms a loft; a badly-flashed one leaks for years. Here is what a proper job involves.
When it is not the answer: If an existing Velux only leaks at the flashing, that is a re-flash, not a new window Read the full guide.
Victorian terraces off the Wellingborough Road and in Semilong mean rear-access scaffold and permit-controlled pavement space, while the post-war estates have easier side access. Nene Valley humidity keeps north-facing roofs damp and slow to dry through autumn.
We cover Semilong, St James, Wellingborough Road and the wider NN1, NN2, NN3, NN4, NN5 area, and price every velux & skylights job against the specific stock and access on your street — not a one-size guess.
Most Northampton homeowners who call us about velux & skylights have noticed a dark loft room or landing you want to light. The way we approach it depends on your property and street. Victorian terraces off the Wellingborough Road and in Semilong mean rear-access scaffold and permit-controlled pavement space, while the post-war estates have easier side access. That local reality — the stock era, the access, and nene valley humidity keeps north-facing roofs damp and slow to dry through autumn — is exactly what we price against, rather than a one-size national rate.
Done properly, locally. Rooflights are set with the correct flashing kit for your covering so they stay watertight for good. Workmanship is guaranteed for 10 years; Velux units carry their own manufacturer warranty. Because we are based here and rely on our Northampton reputation, we turn up when we say, keep the site tidy — some internal dust where the ceiling is opened; we sheet the room and clear up thoroughly — and stand behind every job in writing. We cover Semilong, St James, Wellingborough Road and the surrounding roads, and we are happy for you to get other quotes: a proper roofer expects it.
Based in Northampton since 2004. We know the housing stock and the problems that return every winter.
Our own team on every job — not a national company farming leads to subcontractors.
No call-out fees, no hidden extras. You'll know the full cost before we start.
Written guarantee on all workmanship. We stand behind every job.
Industry-recognised standards for quality, safety and workmanship on every project.
"New Velux fitted into the loft bedroom conversion on the 1930s semi. Correct flashing kit specified for the clay plain tiles, dressed properly. No leaks in two winters and the light upstairs is transformed."
"Existing Velux had failed double-glazing — misting and condensation between the panes. Sealed unit replaced rather than full window, at a fraction of the cost. Quick, clean and exactly what was needed."
"Leaking Velux that three previous roofers had patched with sealant — still leaked. Northampton Roofing replaced the full flashing kit with the correct profile for the tile. Bone dry ever since."
A standard Velux supplied and fitted including correct flashing kit typically costs £600-£1,200 depending on size and tile profile. Sealed unit replacement is £200-£400. Flashing-only replacement is £250-£500. Flat rooflights and roof lanterns are £800-£2,500. Free no-obligation quotes on all work.
Most Velux installations fall under permitted development — provided the window does not project beyond the existing roof plane and meets size limits. Conservation area properties and listed buildings are different: check with West Northamptonshire Council before proceeding. We can advise on likely requirements during the survey.
Not necessarily. Most Velux leaks trace back to a failed flashing kit (repairable without window replacement), a failed sealed unit (replaceable independently), or a degraded weatherstrip (replaceable on most models). Full window replacement is only needed when the frame itself has deteriorated. We diagnose on site and quote the most cost-effective fix.
Yes — and this is the most cost-effective time. Scaffold and tile removal for re-roofing makes Velux installation almost free in labour terms. If you are planning a re-roof we will always ask whether you want to add or upgrade Velux units at the same time.
The most popular sizes for 3-bed semis in Northampton are MK04 (78x98cm) and FK06 (66x118cm). Sizing depends on rafter spacing and light requirements for the room. We measure and specify during the survey and present size options before confirming the order.
In most cases yes, for installations between existing rafters where no rafter is cut. If a rafter needs cutting to fit a larger window, a structural assessment is required. We assess during the survey and advise if structural involvement is needed before proceeding.
Clean the sealed unit with non-abrasive glass cleaner. Inspect the flashing collar annually for moss growth and ensure drainage channels on the frame are clear. Check the weatherstrip around the frame is not compressed. Most Velux maintenance is straightforward from inside the loft space.
No call-out fees. No obligation. An honest quote from a local Northampton roofer.
0160 428 1189 ✉ Email Us InsteadWe check the pitch, tile profile and structure to size and position the window.
Priced for supply and fit, including the correct flashing kit for your covering.
Rafters trimmed as needed, the window set in, and the flashing dressed to be watertight.
We test for water-tightness and make good inside.
| Job | Typical duration |
|---|---|
| Swap a like-for-like Velux | Half a day |
| New rooflight into existing roof | 1-2 days |
| Multiple or larger units | 2-3 days |
We fit rooflights in dry conditions and weatherproof the opening if work spans more than a day.
Rooflight work is done from scaffold or a tower with the opening protected throughout. Scaffold is specified for: any rooflight above single-storey height - always itemised in your written quote, never a hidden extra, and we arrange it.
Victorian terraces off the Wellingborough Road and in Semilong mean rear-access scaffold and permit-controlled pavement space, while the post-war estates have easier side access. Pavement scaffold and skip permits go through West Northamptonshire Council; allow a few working days on streets like Semilong, St James, Wellingborough Road where space is tight.
| Job | Typical range | Notes |
|---|---|---|
| Swap a like-for-like Velux | £400-£800 | Plus the unit |
| New rooflight into existing roof | £900-£1,800 | Incl. flashing |
| Larger or multiple units | £1,800-£4,000 | Design-dependent |
| Re-flash a leaking rooflight | £250-£600 | Repair only |
Worked example: A new Velux into a loft room on a semi in Duston: around £1,250 supplied and fitted with the correct flashing.
No deposit on repairs under £500. Staged payments on larger jobs - nothing up front before materials are on site. All prices include VAT; a written itemised quote every time.
Covering NN1, NN2, NN3, NN4, NN5 and surrounding postcodes.
Workmanship is guaranteed for 10 years; Velux units carry their own manufacturer warranty.
If a fault appears in covered work, we come back and put it right. No quibbling, no re-charge.
Some internal dust where the ceiling is opened; we sheet the room and clear up thoroughly. You do not need to stay home for external work - we just need power and access agreed in advance.
The roof is never left open to weather; we make the opening safe and dry at the end of each day. Nene Valley humidity keeps north-facing roofs damp and slow to dry through autumn.
Last updated: August 2026
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