Which Velux size is most common in Worthing properties?

MK04 (78×98cm) and MK06 (78×118cm) are the most common sizes in Worthing's 1930s–1960s residential stock, where rafter spacing is typically 400–450mm centre-to-centre. We confirm the correct size at the survey stage based on your specific rafter spacing and the desired finished opening.

What is the difference between a roof window and a rooflight in Worthing planning terms?

A roof window (Velux-type, opening) and a rooflight (fixed, flush or raised) are both normally permitted development on residential properties in Worthing, subject to the same 150mm protrusion limit. Conservation area and listed building exceptions apply. We advise on the planning position for your specific property before quoting.

Velux & Skylights Worthing | Installation & Repair

Q: Can a leaking Velux be repaired without replacing the unit?

In the majority of Worthing cases, yes. Blocked drainage channels, failed foam flashing and degraded sealants are all repairable without unit replacement. We diagnose the specific cause before recommending. Call 01903 905 128 to arrange a diagnosis visit.

Velux & Skylights Worthing

Velux Installation & Repair in Worthing

Roof window installation is one of the most frequently botched roofing jobs we encounter in Worthing. The standard Velux EDN foam flashing kit is adequate for sheltered inland properties — but in a coastal environment, foam degrades faster, salt air attacks the adhesive bond, and the thermal cycling from direct south-facing sun causes premature failure. We install Velux windows with hand-dressed lead flashings and Code 4 soakers as standard, giving a joint that will outlast the unit itself.

The most common Velux problem we diagnose in Worthing is a failed or blocked drainage channel on the bottom rail — a design element that regularly silts up on coastal properties due to salt and algae deposits in the glazing channel. We clear and reseal these as a first step before recommending replacement, and in the majority of cases this resolves the leak without the need for a new unit.

Velux & Skylight Services in Worthing

New Velux roof window supply and installation — all sizes
Replacement of failed or outdated roof windows
Velux leak diagnosis and repair
Lead flashing kit upgrade on foam-flashed installations
Fixed rooflights and flat roof domes
Loft conversion window installations
Drainage channel clearing and seal replacement

Velux Prices — Worthing

Single Velux supply & install (MK04)£600–£900

Single Velux supply & install (MK06)£750–£1,100

Replacement unit (same size)£400–£750

Lead flashing upgrade (existing unit)£250–£450

Leak diagnosis & repair£150–£350

Why Lead Flashing on Coastal Worthing Installs?

Foam flashing lifespan (coastal)8–15 years

Lead flashing lifespan40–60 years

Salt air resistance (foam)Poor

Salt air resistance (lead)Excellent

Included in our coastal spec✓ Standard

Worthing Roofing Experts 📍 Worthing, West Sussex BN11 📞 01903 905 128 🕐 Mon–Fri: 8am–6pm · Sat: 8am–2pm ⚡ Emergency: 24/7

Velux & Skylights Worthing

Velux Installation in Worthing — What to Know

Foam Flashing Kits vs Lead — The Coastal Reality

The standard Velux EDN foam flashing kit is adequate for sheltered inland properties — it is what most Velux installations in the UK use and it works for its design life of 15–20 years in benign conditions. In Worthing's coastal environment, the same foam kit degrades significantly faster. Salt air attacks the adhesive bond between foam layers. Thermal cycling from intense south-coast sun causes foam expansion and contraction that opens micro-gaps over time. The result is foam flashing failure at 8–12 years on Worthing coastal properties — sometimes less on direct seafront installations. We install all Worthing Velux units with hand-dressed lead flashings as standard. The lead adds cost to the installation — approximately £150–£250 per unit — but eliminates the replacement cycle entirely on the flashing element.

Diagnosing a Leaking Velux in Worthing

The majority of leaking Velux calls we attend in Worthing do not require a new unit. The most common cause of Velux leaks on Worthing coastal properties is a failed or blocked drainage channel in the bottom sill rail — a design element that accumulates salt and algae deposits on coastal properties, restricting drainage and causing water to back up behind the lower seal. Clearing and resealing this channel resolves the leak in the majority of cases. The second most common cause is failed foam flashing at the uphill edge of the unit — resolvable by replacing the foam kit with lead. Only if the glazing seal or the frame itself has failed is unit replacement required. We diagnose before recommending.

Planning and Building Regulations for Velux in Worthing

Standard Velux roof window installation is permitted development on most Worthing residential properties — no planning application required. The conditions are: the window must not protrude more than 150mm above the roof plane when closed; it must not be on a front elevation facing a highway; and the property must not be in an area where permitted development rights have been removed. Properties in the Tarring conservation area should check with Worthing Borough Council before installation. Building regulations notification is generally required for Velux installation as part of work affecting the thermal envelope.

Installation Type	Flashing Spec	Guarantee	Typical Cost
New unit (MK04) — lead flashed	Code 4 hand-dressed	25yr material + 10yr work	£650–£950
New unit (MK06) — lead flashed	Code 4 hand-dressed	25yr material + 10yr work	£800–£1,100
Replacement (same size)	Lead or foam match	10yr work	£400–£750
Foam-to-lead upgrade	Code 4 replacement	10yr work	£250–£450
Leak diagnosis and repair	As required	10yr work	£150–£350
Drainage channel clear/reseal	Sealant replacement	2yr work	£120–£250

Velux on Loft Conversions in Worthing

Loft conversions in Worthing's 1930s detached stock — common across Goring-by-Sea, Durrington and the larger semis of West Worthing — typically use Velux windows as the primary light and ventilation source. Correct installation in these properties requires understanding the existing roof structure: rafter spacing, batten position and felt underlay type all affect how the flashing kit is installed. We carry out loft conversion Velux installations on Worthing properties regularly and can advise on sizes and specifications that maximise light while meeting the 150mm protrusion limit for permitted development.

Customer Reviews

Velux & Skylight Reviews — Worthing

★★★★★

"Had two Velux units installed in a loft conversion in West Worthing. The flashings were fitted correctly with full lead soakers, not just the foam kit. Still completely dry two years on, including after the January storms."

Tim F. · West Worthing BN11

★★★★★

"Leaking Velux that three roofers had looked at and 'fixed'. These guys found a failed drainage channel on the bottom sill in 10 minutes. Cleaned and resealed, dry ever since. No replacement needed."

Jackie P. · Lancing BN15

★★★★★

"Replaced an old, single-glazed rooflight in our Durrington bungalow with a new Velux. Done in half a day, properly flashed with lead, and the difference in natural light upstairs is remarkable."

Colin R. · Durrington BN13

FAQ

Frequently Asked Questions

A single Velux roof window supply and installation in Worthing typically costs £600–£1,200 depending on size, specification and access. Multi-window projects are costed per unit. Replacement of an existing Velux unit costs £400–£800. Call 01903 905 128 for a free quote.

In most cases no — standard roof windows are permitted development provided they don't protrude more than 150mm from the roof plane. Properties in Tarring conservation area or with Article 4 directions may require prior approval. We check planning status before quoting on every job.

Yes. Salt deposits accumulate on the glazing and frame seals of roof windows on seafront and near-seafront properties in the BN11 postcode area. We recommend annual inspection of the rubber seals and drainage channels, and re-lubrication of mechanisms on opener units every two years.

Yes. Velux leaks are usually caused by failed flashing kits, degraded rubber seals, or blocked drainage channels rather than the unit itself. We inspect and diagnose on site and can often resolve the leak without full replacement. Where the unit is beyond economic repair, we supply and install replacement Velux windows.

MK04 (78×98cm) and MK06 (78×118cm) are most common in Worthing's 1930s–1960s stock where rafter spacing is typically 400–450mm. We confirm the correct size at survey stage based on your specific rafter spacing.

In most Worthing cases, yes. Blocked drainage channels, failed foam flashing and degraded sealants are all repairable without unit replacement. We diagnose the specific cause first. Call 01903 905 128.

Both are normally permitted development on residential properties subject to the same 150mm protrusion limit. Conservation area and listed building exceptions apply. We advise on the planning position for your property before quoting.

Velux & Skylights Worthing

Velux Installation & Repair in Worthing

Velux & Skylight Services in Worthing

Velux Prices — Worthing

Why Lead Flashing on Coastal Worthing Installs?

Velux Leaking?

Velux Installation in Worthing — What to Know

Foam Flashing Kits vs Lead — The Coastal Reality

Diagnosing a Leaking Velux in Worthing

Planning and Building Regulations for Velux in Worthing

Velux & Skylight Reviews — Worthing

Frequently Asked Questions

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