A rooflight, often called a skylight, is a window installed in a pitched or flat roof to provide more light. Rooflights can reduce CO2 emissions by cutting down on electric lighting.
Installing a new rooflight usually requires Building Regulations approval, though some exemptions exist.
Property owners must ensure compliance with planning rules and building regulations. Non-compliance can result in liabilities, including demolition or restoration.
Always consult with local planning authorities and building control services before starting work to avoid issues.
Planning permission is often not required for rooflight installation. However, Building Regulations approval is usually needed to ensure the roof's integrity and safety. Factors include the rooflight's weight and thermal performance.
There's no size limit for rooflights from a planning perspective if it fits within a historically reasonable size.
A glazing bar can reduce the perceived size and may be required for traditional properties by local planning authorities.
Always check with local planning officers for specific requirements.
Read more about glazing bars
Part B of the Approved Document recommends enhanced glazing/fire integrity with a minimum unobstructed openable area for emergency escape or smoke ventilation (BS EN 12101-2).
Rooflights should meet these classifications based on their material. Non-plastic rooflights must adhere to the relevant classification in the table opposite.
All Stella rooflights use grade 316L stainless steel, which offers numerous benefits over other materials. Stainless steel is ideal for construction due to its oxidation resistance and strength at high temperatures.
While stainless steel lacks an intrinsic fire rating, its fire resistance is tested under precise conditions (BS476 parts 20, 21, and 22). Stainless steel resists ignition and minimises flame spread. It remains stable and inert under oxidizing conditions found in flames and heat sources.
Research shows stainless steel surpasses carbon steel, aluminum, and galvanized steel in corrosion resistance, durability, and fire prevention. For more details, visit the Gov.uk Planning Portal.
Read more about Part B Fire Regulations
Part F aims to ensure proper ventilation to limit moisture and pollutants, preventing mold and health hazards. Stella rooflights offer fixed and opening designs. Smaller casements can be manually operated, opening to around 250mm, while larger ones use electric actuators. These actuators are customised and offer various options based on specific customer needs.
Our electric rooflights include accessories for Part F compliance, like sensors and remote controls.
Stella use the most technically advanced ventilation control systems, manufactured in Germany by D+H Mechatronic. Ensuring industry leading performance, safety and energy efficiency.
Please note, Stella Rooflights do not incorporate trickle vents due to their low-profile design.
For more details on Part F, visit the Planning Portal.
Read more about Part F Ventilation Regulations
There is no legal requirement for non-fragile rooflights, unless specified by the customer. A risk assessment should be undertaken to control the risks around any roof work.
Use safety glass, like toughened, laminated, or wired glass, for all overhead applications. Rooflights on accessible but non-traffic roofs should be non-fragile to prevent accidents.
Assess roof access needs during design and specify accordingly, supported by risk assessments.
Stella conservation rooflights are fragile and not for walk-on use.
Architects, engineers, and manufacturers should discuss large installations early to avoid issues. Ensure large, high-up glazing areas meet BS 5516-2: 2004 standards.
Inner panes must be laminated if rooflights are over 5 meters above floor level or over water. Toughened glass can be used in other cases with a thorough risk assessment.
Avoid leaving these considerations to the builder at the last minute to prevent complications.
Read more about Part K Building Regulations
When specifying rooflight glass, the combination of interlayer and glass panes is crucial for performance. Laminated glass, made of two or more glass sheets bonded with a plastic interlayer, ensures safety as it holds together when broken and can be used overhead.
Annealed glass is weaker than toughened glass and prone to thermal fracture, caused by temperature differences due to shadows or nearby reflective surfaces.
Stella's bespoke rooflights allow customers to specify the right glazing for their projects.
Part L of the Building Regulations were recently updated, as the UK Government continues its drive towards greater thermal efficiency in house building.
Find out how this impacts the rooflight industry by reading our blog.
Rooflights provide bright, natural light, reducing the need for artificial lighting. Natural daylight is free and unlimited, lowering CO₂ emissions from reduced energy use.
Buildings without rooflights can have over 50% higher CO₂ emissions. An optimal rooflight area is 15% or more of the floor area.
Building regulations require roof windows to have a thermal performance of WER Band C or U-value 1.6 W/(m².K). Roof windows should be tested per BS EN ISO 10077-1:2017 for thermal transmittance.
There are some exceptions which include where the replacement windows are unable to meet the requirements because of the need to maintain the external appearance of the façade or the character of the building, replacement windows should therefore meet a centre pane U-value of 1.2 W/m2K.
There are also additional exemptions for Listed buildings and those in designated conservation areas and we would advise that further guidance is sought from your local authority concerning any requirements which specifically relate to your project.
What this test will provide is a thermal performance (u-value) figure based on installation at both horizontal and vertical inclination. This is somewhat problematic for most in-plane rooflights as their design does not allow for their use in either horizontal or vertical settings, so it is always advisable to discuss your roof pitch with your rooflight supplier.
There are also other factors which need to be taken into account as most rooflight companies will provide their highest specification as the test sample. This means that any changes to glazing specification and addition of things such as glazing bars are likely to alter the u-value as much as the pitch of the roof.
For more on rooflights and U-values, read our blog.
U-What?! Understanding Rooflight U-Values
Minimising uncontrolled air leakage is crucial for energy efficiency, often assessed through a weather performance test.
Part L of Building Regulations mandates standards for air permeability, water-tightness, and wind resistance in rooflights. Air permeability, rated from Class 1 to Class 4 (highest), measures draftiness.
Stella Rooflights achieve the highest ratings for Air Permeability and Wind Resistance.
Read more about Part L Building Regulations
For listed buildings, significant internal or external work requires consent. Homes in conservation areas or areas of outstanding natural beauty may have additional restrictions; consult your local authority for guidance.
Navigating Building Regulations can be complex. Seek advice from a qualified professional to ensure compliance.
Stella offers bespoke rooflights, tailored to your project's needs. We are available to discuss requirements and provide guidance on framing materials, glass, thermal performance, and safety.
For more information, email info@stellarooflight.co.uk.
If you would like to receive a printed version of our brochure feel free to email us at info@stellarooflight.co.uk. A digital version is also available to download.
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Speak to usWe would love to hear about your unique project! Contact us with your rooflight enquiry and our knowledgeable team will be pleased to help.