If you’re buying a new build home constructed with light steel frame (LSF), you’re purchasing a property built using one of the most modern construction methods available in the UK today. Light steel framing offers numerous advantages, from rapid construction times to excellent thermal performance and design flexibility. However, understanding what standards should govern this type of construction can help you make a more informed purchase and know what to look out for during your snagging inspection.
We’ve just published a comprehensive guide to NHBC Standards Chapter 6.10, which covers light steel framed walls and floors in detail.
Light steel frame construction is becoming increasingly popular with major UK housebuilders. The method involves creating the structural framework of the home from cold-formed steel sections, typically between 0.45mm and 4.0mm thick, which are then clad externally (often with traditional-looking brick or render) and lined internally with plasterboard.
From the outside, an LSF home often looks identical to a traditionally built property. You might not even realise your new home uses steel framing unless you specifically ask or check the construction details. This modern method can deliver homes that are energy-efficient, quick to build and structurally sound, but only when constructed to the correct standards.
Why Standards Matter for LSF Homes
The NHBC publishes detailed technical standards that builders must follow when constructing LSF homes. Chapter 6.10 runs to 18 pages of technical requirements covering everything from the grade of steel and corrosion protection to acoustic performance and moisture control. These aren’t arbitrary rules but essential safeguards developed through decades of construction experience and research.
Understanding these standards matters because light steel frame construction is fundamentally different from traditional building methods. Steel behaves differently to timber or masonry. It conducts heat readily, so thermal bridging must be carefully managed. It can corrode if not properly protected, particularly at low level where moisture is present. The connections between steel members must be precisely designed and executed. The integration with cladding, insulation and weatherproofing requires careful attention to detail.
When these standards are properly followed, you get an excellent home. When they’re not, problems can range from minor inconveniences to serious structural or weatherproofing issues that are expensive and difficult to rectify.
The Hidden Nature of LSF Construction
One of the key challenges with light steel frame homes is that many critical elements become hidden as construction progresses. By the time you view your nearly-complete new home, the steel frame is completely concealed behind internal plasterboard and external cladding. You cannot see the structural connections, the corrosion protection on the steel, the wall ties connecting the frame to the masonry, the breather membranes and vapour control layers managing moisture, or the insulation preventing heat loss.
This hidden nature makes it absolutely essential that proper inspections are carried out during construction by building control and NHBC inspectors. It also means that a snagging inspection, whilst valuable for identifying visible defects, cannot verify that all these hidden elements have been correctly installed. What a snagging inspection can do is identify visible symptoms that might indicate hidden problems, along with all the finishing defects that commonly occur in new build homes.
Key Areas of Concern for Buyers
Our detailed knowledgebase article covers all aspects of NHBC Standards Chapter 6.10, but several areas are particularly important for buyers to understand.
Structural certification is a crucial safeguard. LSF homes with primary structural components should have undergone a two-stage certification process. First, the manufacturer’s LSF system itself should be certified by the Steel Construction Institute. Second, the specific design of your home should be checked by an independent NHBC-registered LSF certifier. This two-stage process provides assurance that both the system and its application in your particular home have been reviewed by qualified engineers.
Moisture control requires careful attention in LSF construction. The base of the steel frame should typically be kept at least 150mm above external ground level, with enhanced corrosion protection required where this isn’t achievable. Clear cavities must be provided between cladding and insulation to allow drainage and ventilation. Breather membranes and vapour control layers must be correctly installed to manage moisture movement through the structure. When moisture control fails, the consequences can include corrosion of the steel frame, deterioration of insulation, and conditions conducive to mould growth.
Fire safety is rigorously addressed in the standards, with specific requirements for fire-stopping around service penetrations, cavity barriers to prevent fire spread, and materials selection to achieve required fire resistance periods. Following recent tragic incidents involving external wall systems, the fire performance of insulation and cladding has come under increased scrutiny, making compliance with these standards more important than ever.
Acoustic performance is achieved through careful design and construction of separating walls and floors between dwellings. Even small gaps in construction can significantly compromise sound insulation, allowing noise from neighbours to impact your quality of life. The standards specify how walls and floors should be constructed to meet building regulations requirements for sound insulation.
What Can Be Checked During a Snagging Inspection
When our qualified inspectors examine an LSF new build home, we focus on what can be seen, measured and tested without destructive investigation. We look for visible construction defects, poor finishes, missing components, and symptoms that might indicate hidden problems.
For example, we can identify cracks around openings that might suggest inadequate lintels, floors that feel excessively bouncy indicating deflection problems, signs of moisture penetration suggesting inadequate weatherproofing, missing or blocked weepholes in cavity walls, poorly finished joints in plasterboard, gaps around service penetrations that should be fire-stopped, and evidence that external cladding hasn’t been properly detailed to accommodate movement.
What we cannot do is verify that hidden structural connections have been made correctly, confirm that the specified grade and thickness of steel has been used, check that corrosion protection extends to areas we cannot see, verify that wall ties are present at the correct spacing within closed cavities, confirm that breather membranes and vapour control layers have been correctly installed, or measure the thickness and coverage of concealed insulation.
This is why inspection during construction is so important, and why understanding the standards helps you ask the right questions of your developer.
Learning from the Standards
Our comprehensive knowledgebase article breaks down NHBC Standards Chapter 6.10 section by section, explaining what each requirement means in practical terms. We cover structural design requirements for floors and walls, the specification and protection of steel and fixings, how roofs should interface with LSF construction, requirements for insulation and moisture control, the critical role of breather membranes and vapour control layers, how cladding should be integrated with the frame, and much more.
The article is written in plain English rather than technical jargon, making these complex standards accessible to homebuyers who want to understand what should have been done during construction of their new home.
Whether you’re considering purchasing an LSF new build, you’re waiting for one to be completed, or you’ve already moved in and have concerns about the construction quality, understanding these standards empowers you to make informed decisions and ask pertinent questions.
Taking Action
If you’re buying a light steel frame new build home, we recommend reading our full guide to NHBC Standards Chapter 6.10 in our knowledgebase. Understanding these requirements will help you appreciate the complexity of modern construction and the importance of ensuring standards are met.
Before you complete on your purchase, consider commissioning a professional snagging inspection. Our experienced inspectors will examine all visible and accessible aspects of your new home, identifying defects and issues that should be rectified by the developer whilst the property is still their responsibility. Our detailed reports provide you with clear documentation to support your discussions with the developer, helping ensure you move into a home that meets the standards you have every right to expect.
Light steel frame construction, when executed properly to NHBC standards, delivers excellent homes that are energy-efficient, durable and comfortable. Our role is to help you verify that your particular home has been built to these standards by identifying any visible defects or concerns.
Read the full guide to NHBC Standards 6.10 for Light Steel Framed Homes
Or contact us today to discuss how our snagging inspection services can give you peace of mind about your new build purchase.