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Our Oversized Custom Size Roof Windows Calculator is specially designed for ambitious projects that require large dimensions. This intuitive tool allows you to customize the dimensions and features of your skylight, ensuring that even the grandest visions can become a reality.
This calculator is uniquely designed to handle large sizes, perfect for both flat and pitched roofs. You have the freedom to specify widths from 300mm to an impressive 2700mm, and lengths from 1500mm to a remarkable 5800mm. This flexibility enables you to create a skylight that’s perfectly sized for your expansive roof.
Further, tailor your skylight by selecting the border or overhang of your choice. With options of 50mm, 100mm, or 150mm available, you can ensure the overhang perfectly complements your skylight design and enhances the overall aesthetics of your architecture.
Our Oversized Custom Size Roof Windows Calculator also enables you to select your preferred glass tint. Opt for a Clear Tint to maximize light penetration, a Green or Blue Tint for a touch of colour, or Solar Glass to maintain optimal light transmission while minimizing heat gain.
All of our custom size skylights are triple-glazed for excellent thermal efficiency. Please note that the quoted size is the internal size, which ensures a precise fit for your installation.
Upon placing your order, you can expect delivery within an estimated 3 to 6 weeks. We’re committed to ensuring your bespoke skylight reaches you as swiftly as possible. To add to your convenience, we offer Free Nationwide UK Delivery.
Start realizing your grand visions today using our Oversized Custom Size Roof Windows Calculator. Enjoy the freedom of customizing each aspect of your oversized skylight and anticipate the transformation of your space with abundant natural light. With our bespoke, perfectly fitting skylight, your dream space is within reach.
All our shipping is Free of charge on orders over £400 within the London (M25) Area.
All standard sizes Flat & Pitched Skylights are delivered between 3 to 6 working days.
All Custom Size orders take 3 to 6 weeks to be produced and shipped over to the UK. They are free of delivery fees.
Roof Lanterns delivery is within 10-14 working days from the day the order was placed.
Framed Skylights delivery is within 10-14 working days from the day the order was placed.
Electric Opening Skylights delivery is within 10-14 working days from the day the order was placed.
Walk-On Skylights delivery is within 10-14 working days from the day the order was placed.
Skylight Blinds delivery is within 10-14 working days from the day the order was placed.
Monday to Friday from 8 am until 5 pm.
We will contact you to arrange a suitable delivery time, once payment has been processed.
Please add to cart the products you want and enter the shipping address to view delivery cost.
Our own drivers deliver within London (M25) in order to guarantee the safe arrival of all our products.
Please be aware that as our drivers are alone and pre-loaded in our warehouse, we will require you or your builders to be on-site for the acceptance of all orders.
For orders outside M25, we use an external shipping network. Once sent, they will call you to book a suitable date and time for delivery.
The Extra Economy Shipping options work for all areas, except Northern Ireland and Scotland.
Some of these companies may not have the correct vans in place and might not be able to deliver to your door, so we might have to ask you to pick it up from the local depot (usually within 20 min drive) however this is rare.
Most of our products weigh a considerable amount varying from 10kg to 280kg, therefore it may need more than two, four, or even six people to unload depending on the size and weight of your product.
We will not accept liability for any broken skylights during the unloading process, as it is down to the customer to organise this process.
In the event that the customer does not attend the delivery appointment or no one is there to accept your product, we will try and contact you via phone, text, and voicemail before our driver leaves your delivery address.
If no contact is made, we will have no option but to return your product to our warehouse.
Installation Guides
Our skylight installation guide provides clear and concise instructions to help you easily install our range of roof windows. From flat roof windows to pitched roof windows, our guides guide you step-by-step through the process, ensuring a hassle-free installation.
Bear in mind our Skylights sizes are the sizes of the bottom (internal) glass panel. The top panel is stepped by 100mm on each side, and the overall externally visible size is 200mm bigger in both directions:
For example, only in this guide will we present installation sketches for a Skylight 600mm x 600 mm. For all other sizes, we provide installation sketches in the gallery of each size separately.
Double/Triple Glazed Skylight 600x600mm has the following sizes:
A minimum pitch of 8-10 degrees relative to the horizon must be provided to avoid water pooling in the middle of the glass panel (for every metre of Skylight a 10cm fall is required). It is worth spending a few extra minutes before applying the silicone to run a water test to ensure the water is not pooling (even though you are installing glass it will still bend in the middle). The internal distance upstand to upstand needs to be 10mm bigger than the quoted skylight size (in our example: 610mm by 610mm).
Upstand opening should allow for 5mm tolerance on each side:
Install the support in such a way that the top of support is as follows:
-Triple Glazed Skylight – 46mm below the top of upstand
The Skylight support is a 25x50mm (2”x1” ) timber:
Apply the roof covering material to cover the external face and top of the upstand.
Make sure all surfaces where the silicone will be applied are clean of dirt, dust, moisture, etc.
Once you finish weathering the upstand, you are ready to install the Skylight.
Installation Guides
Accessories
Easily complete your skylight installation with our range of high-quality skylight installation accessories.
We offer a 20 year seal warranty on all our skylights.
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Our warranty is CE certified and meets European standards. As long as you install your skylight unit as per our instructions, the warranty is valid for twenty years. This covers you for any defects or damages, and we offer an aftercare service.
All our Skylight prices are on our product page. Discounts may be given if an order is above £2/5000 given as a trade price. Please contact our Customer Support Team for more information if you wish to make a large order so we are able to give you a discount code.
Yes, you can! Once you have placed and paid for your order, please get in touch with our Customer Support Team who will arrange someone to prepare your order for collection.
Yes, you can, if you go through to checkout, it will work out the delivery costs and options without placing an order.
No, we do not install. We only supply the skylights. We recommend looking for a reputable roofer within your area who can carry out the installation professionally.
Yes, we offer fixed and openable skylights.
The maximum value our skylights has is 0.9 W/m²K
Yes, you can have them installed once your skylight is fitted! As the installation of blinds behind the glazing increases the risk of Thermal Stress Glass Breakage, we advise you to install the blinds at a minimum distance of 150 mm from the glass.
All our Skylights come triple-glazed which provides optimum sound insulation. This, in turn, would help minimise any rain noise. The more panes of glass, the better the noise resistance and the greater the distance between each glass, the better your sound insulation will be. All our skylights are designed with these factors in mind. We offer triple glazed skylights with 6mm toughened safety glass as standard and a generous 15mm gap between the panes and bottom. Panes are 8mm thick reducing noise to maximum.
Our skylights are manufactured in Europe.
Skylights1.co.uk guarantees in supplying top quality products at the Best Price, due to manufacturing and delivering everything in house.
Do these come as standard or do I need to order them separately? You will need foam rope, weather proofing silicone and flashing kits along side your skylight. We have all of these on our website so you can order everything you need from us so you are ready to go.
Yes, we offer express delivery to most postcodes. Please check this service on our website or give us a call.
We accept PayPal, Credit and/or Debit Cards (Stripe), Google Pay, Amazon Pay and Direct Bank Transfer. You will see these payment methods offered to you upon check out. Unfortunately, we only accept payment in advance.
It is important to have your skylight installed at a slight angle relative to the horizon to allow water to run off the glass and avoid pooling. We recommend setting the rooflight at an angle of 45°. It is worth it to spend a few extra minutes before applying the silicone to run a water test.
Lead time depends on the size of the unit and the exact location in the UK, please add the item to your card and your delivery postcode and you will see all delivery options to your location-keep in mind that you will not be charged at this stage.
Minimum 6, maximum 45 degrees.
The website is the only place to place an order, and we don't take orders over the phone- but we are always contactable to answer any questions at any point.
Yes, just let us know any instructions for delivery or delivery dates in the “notes” box during checkout.
You can order a tint for your skylight by selecting the option on our custom calculator, we offer a green or blue tinted option.
No, the skylights arrive ready to install (don’t forget to order your accessories separately so you can be ready to go).
Triple Glazed skylights tend to have a better U-Value and Noise Resistance. What this means is that a triple glazed skylight will have better noise reduction properties if you live in a noisy area. The lower U-Value benefit of them is that they have less heat loss. So if you plan on having a larger skylight or more than one skylight on your extension letting in more natural light we would recommend going for triple as it will save you on your energy bills and lose less heat.
Double Glazed Skylights tend to be lighter in weight and easier for installations however they are not as good on heat loss and noise reduction as triple.
Vanessa Spencer –
The amount of natural light flooding into our living room from the custom size roof window we had fitted is nothing short of a revelation. Morning coffee has turned into a zen-like experience, and even gloomy, rainy days have a certain charm now. Plus, it’s great for our indoor plants, they’ve never looked healthier!
Nathan Davis –
I placed my order for a custom size skylight and was surprised when it arrived so quickly. The skylight itself is fantastic – high quality and just as described.
Patrick Hakansson –
I was really impressed with the fast delivery times, even for custom sizes which is rare these days. The team was knowledgeable and that was what secured the sale for me. I’m glad I found them!
Simon Thomas –
Our experience with Skylights one has been nothing short of fantastic. Their friendly customer support, especially Lily and Tedi, guided us throughout the process and helped us choose the perfect made to measure roof window for our home.
Blake Lee –
Having a custom size roof window in our home office has significantly improved our working from home experience. The abundance of natural light has increased our productivity, and it’s also proven to be a great conversation starter in video meetings!