Decoded: Structural Engineer Drawings Compared to Buildings Regulations Drawings

Whether your renovation plans are signed and sealed or you’re just thinking about the logistics, one thing to have in mind is that your project needs to meet UK building regulations. These legal requirements are a set of standards for the structural design, construction and alterations of buildings to ensure they’re safe, sustainable and accessible. The legislation covers a huge spectrum of things, from ventilation and fire safety to structure and electrics. 

If you’re making significant changes to your home (like an extension, loft conversion or reconfiguring floor plans), you’ll need documentation that proves you meet UK building regulations. Enter structural engineer drawings and building regulations packages. These are both important parts of the design and approval process, but they serve different purposes and contain distinct information. Structural engineering drawings focus on the structural integrity of your home while building regulations packages ensure compliance with national or local building standards. 

Here we breakdown the two documents and the purposes they serve so you can figure out what you need for your project. 

What are structural engineer drawings?

Structural engineer drawings are technical drawings including structural calculations carried out by your structural engineer that ensure any modifications maintain your home’s stability and safety. Basically, they ensure nothing’s going to fall down if you’re changing the structure of your property. Knocking through walls or adding new loads to the original structure (like new flooring or heavy fixtures) can compromise the integrity of the building if not done correctly, so it’s important to make sure you have the right measures in place from the off.

These drawings are necessary for approval from building control, plus your contractors will refer to them throughout your construction project. 

Renovation work is also often done on older properties, which might not meet the stricter building codes of today. Structural drawings can help to bring homes up to current standards, addressing issues like poor foundations or outdated materials. 

What do structural engineer drawings cover?

Structural engineer drawings specify the materials, dimensions and techniques needed to ensure your home’s safe to live in. The nitty gritty depends on your project, but here’s what’s typically included:

• Structural layouts: Plans that show the positions of structural elements like beams, columns and load-bearing walls. These might also include details of how features are joined, like welding or bolting details, or concrete reinforcement.
• Foundation plans: Details about the foundation design, including size, depth and reinforcement details to support the building’s weight.
• Weight calculations: Information showing the weight of new structures and their load-bearing capacities, ensuring they can hold people and furniture, plus withstand external pressures like wind. 
• Materials needed: The types of materials required (e.g. what grade steel or strength concrete) and their dimensions.

How much do they cost?

How much you can expect to pay for structural engineer drawings depends on the size and complexity of your project, plus how they charge. Some structural engineers might charge a set fee for drawings, while others work off an hourly rate – on average you can expect to pay structural engineers £100 an hour in the UK, but this might be more in London. For a ballpark of costs, take a look at this breakdown of structural engineers’ rates.

What are building regulations drawings?

Building regulations drawings are detailed plans that show your home is compliant with UK building legislation. These documents are often submitted to a local council or building control for approval before work starts. Your contractor can also refer to them throughout your project to make sure your home ticks all the right boxes legally. 

Some structural engineers can put building regulations packages together but more often than not they’re prepared by architectural technologists (who focus more on the practical aspects of design than architects). If you’ve employed an architect for your project, they’ll likely have colleagues who’ll be able to help. If not, don’t worry – find a practice approved by the Chartered Institute of Architectural Technologists.  

What do building regulation drawings cover?

Everything to ensure the building complies with national or local building regulations and standards, which typically includes details on:

• Structural details: Specs for foundations, floors, roofs and load-bearing walls, detailing materials, sizes, and construction process.
• Fire safety: Requirements for fire escapes, smoke alarms, fire doors and materials that can be used that meet fire resistance standards.
• Insulation and energy efficiency: Insulation standards, heating and ventilation specifications and any renewable energy requirements.
• Electrics and plumbing: Placement and safety of wiring, outlets, switches, plumbing fixtures and pipes.
• Ventilation and drainage: Requirements for natural or mechanical ventilation, as well as water drainage and waste disposal systems.
• Sound insulation: Details on soundproofing to limit noise transfer between rooms or adjacent buildings.
• General safety: Additional details on safety standards like balcony and stair dimensions, handrails and slip-resistant flooring.

How much do they cost?

Much like the fees for structural engineer drawings, the cost of  building regulations drawings can vary depending on factors like complexity and location, plus who you hire. 

Here’s what you might expect to pay:

• Small extensions or minor renovations: £500 – £1,500
• Larger extensions or conversions: £1,500 – £3,000
• Building from scratch or extensive refurbishments: £3,000+

Do I need structural engineer drawings and building regulations drawings?

If your renovation involves anything structural, chances are you’ll need both sets of documentation. 

For smaller projects that don’t involve structural changes – like installing new windows or redoing the bathroom – you might only need building regulations drawings without the need for a structural engineer. It’s very rare to be able to go ahead with a project on structural engineering drawings alone – where it could potentially be okay is something like a balcony. 

Getting both sets of drawings not only ensures your home is safe, and compliant should you come to sell, but also protects your contractor. With watertight structural plans to adhere to, they’re safe in the knowledge that they’re carrying out work that adheres to regulations. 

Not started your project yet? Book a call and we can advise you on the renovation process from start to finish, plus match you to a highly skilled, pre-vetted contractor that’s perfect for your project.

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