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“I genuinely thought I wouldn’t pass the requirements due to Over-glazing. Thankfully ATSPACE talked me through the whole process and we reached our pass! Thank you!”

Brad Newton

Uncomplicated compliance =
Happy customer

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Engineers across England
& Wales

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How Much?!

At ATSPACE, we like to be as transparent as possible. That’s why we’ve provided a breakdown of our costs for every service we provide. Simply click on the filter to find out what you can expect to pay when you select ATSPACE as your building compliance partner.  


Overglazed Extension Calculation

Desk Based Service

When the glazing exceeds 25% of the overall extension floor area, to comply with Part L1b of the Building Regulation
Cost £217

Cost Variances - Warm roof - Complex Shape - Super Large Extension

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Please get in touch with the A-TEAM on 0345 6465 454

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Over Glazed Calculation Performed by Energy Experts
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Building Regulations Signed Off

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U-Value Calculations:
U-Values measure the elements of the building’s fabric for heat loss. You need your U-Values to be as low as possible. The lower your U-Values, the cheaper your build will be to run!

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Energy Statements:
Your energy statement will detail how your build will meet the required energy targets. This will also state any cost saving methods available for your build.

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Air Tightness Drawing Review:
To Pass first time, and to build the best possible structure, you need to know exactly how to build an air tight structure.

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Overheating Assessment:
Whether your build is commercial or residential you may require an overheating assessment. Overheating can easily occur!

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Uncomplicated Compliance

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100% Building Control Certified
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Elmhurst – STROMA Accredited

Over-glazing is usually spoken about in relation to extensions. Over-glazing can be an issue if you exceed the maximum allowance for the total glazed area. This is set at 25% of the extension’s floor area.

To get natural light into your build, you will need glazing. This isn’t a problem if you’re within the requirements, but if you’re over the 25%, then you will come across over-glazing issues.

Over-glazing can be an issue, because it can interfere with the energy efficiency of the build. The glazing you use in your build must meet the minimum energy rating of C. This will ensure less heat loss. These compliances are here to ensure you meet the requirements. You can still have your glazing, don’t fear, but you will need to ensure you do it in the correct way.

Part L of the Building Regulations states alternative methods which can be used to ensure that ever needed pass! The SAP will confirm the CO2 emission rate of the build and ensure that your extension will not affect these figures. ATSPACE can talk you through the whole process, understanding is key.

Here at ATSPACE, we pride ourselves on our ability to know exactly how to ensure that over-glazing won’t cause you problems. You don’t need to fear, ATSPACE will do all the hard work, leaving you to sit back and wait for approval. To get the best possible results, you need to access help from the earliest possible stage. This will provide you with the best possible outcome.

Our engineers know exactly how to ensure Over-glazing won’t be an issue. Uncomplicated compliance is our speciality.

Get the best from your extension and get help at the earliest possible stage! Don't let over-glazing sabotage your project, act FAST

Our FREE extensive knowledge bank will provide you with all the information you need about Over-glazing, coupled with the help from our assessors Over-glazing won’t be a problem on your extension.

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Over-glazed extensions can be a challenge to ensure they meet the requirements. ATSPACE can ensure your Over-glazed Extension won’t be a problem. I am pleased to say we have an experienced team who can assist you at any stage of your build. The earlier you seek advice, the better, as with all Building Compliance. ATSPACE can ensure the whole process is smooth and pain free!

ATSPACE has been involved in many Over-glazed Extensions over the years, and with a high first-time pass success rate, why wouldn’t you call us? If you’re looking to book, ask questions or gather information, ATSPACE is here to help!

  • We can offer you:

  • • Fast Quotation

  • • Fast Certification

  • • Largest knowledge bank in our industry

  • • Expert Energy Advice

You'll often hear the term over-glazing in relation to extensions. This is where an extension exceeds the maximum allowance of the total glazed area. We see more homes being built with extra glazing, which can cause issues when considering building regulations.

Part L of the Building Regulations is the part in which you will have to consider when talking about over-glazing. The rules state that you can't exceed the maximum allowed glazed area, which sits at 25% of the extension's floor area.

If you need any more advice, don't hesitate to contact us! We're proud of our 95% customer satisfaction record! I will continue to push ATSPACE forward while meeting all our client's needs.

Paul Whiffin ATSPACE
Managing Director


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Overglazed Extension Calculations - Questions Answered

How Will Over-glazing affect me?

Overglazing increases the heat loss through the building envelope. The more heat loss there is from the overglazed extension, the more pressure you will put on your heating system. This is just the tip of the over-glazing iceberg.

How Can ATSPACE Help With Overglazing?

ATSPACE can complete the calculations to provide you with the certification to give to building control. If you want fast compliance, you’ve come to the right place!

What Is Overglazing?

Overglazing applies to both domestic and commercial properties which have an extension on them with an excessive amount of glass. You need to ensure that you comply with the regulations set out, ATSPACE can help with this, look no further!

Case Studies

Take a look at some of the many ways we’ve helped our clients achieve building compliance success on their projects.

“We failed the requirements and we had lost all hope. Then we came across ATSPACE who helped us see where we were going wrong, not long after we received our certification!”

Charlie Webdale

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“We knew we would have Over-glazing issues so we called on ATSPACE for help. They assisted us from the beginning of our build and we had no problem when it came to passing any of the requirements.”

Heidi Robertson

Early engagement =
Compliance guaranteed, certificates
delivered next day

Customer Scope

Bring All Your Compliance Under 1 Roof. No work is Sub- Contracted out

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Whether you’re working on a residential or commercial development, rely on us to take care of all your design, consulting, compliance and certification requirements, whatever the stage of your project. When everything is under one roof, why go anywhere else?

Design & planning, part built, as built or energy certification, you can be confident that your project will meet compliance every step of the way. All work is done in-house by our team of dedicated engineers and energy assessors, so you can be sure of an efficient, thorough and top-quality service. To find out more about our multi-disciplinary service offering, simply select the service you require by clicking the icons below. In a rush? Contact us now and get put straight through to a technical expert who will handle your enquiry efficiently.

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