Building Regulation Drawings in London

As a Chartered Architectural Technology practice, we often get questioned whether or not Building Regulation drawings are required. Some clients try to save in the wrong places. It is true that not all projects legally require them; however, they’re crucial for ensuring compliance with Part A through Part R of the Building Regulations 2010 (as amended).

Building Regulation Drawings go far beyond basic architectural plans. They’re detailed technical documents that specify critical elements like:

• Structural calculations and beam specifications
• Foundation depths and construction details
• Thermal efficiency calculations (Part L compliance)
• Fire safety measures and escape routes
• Ventilation systems and condensation control
• Drainage layouts and connection details
• Sound insulation specifications for party walls
• Detailed section drawings at 1:20 scale

So why leave this to your builder on site? We understand your builder has built extensions over and over again, but that does not mean they are equipped to design the whole scheme. For example, 100mm thick insulation does not have the same U-value between each manufacturer; therefore, you’re ending up with a specification made up by a builder which may, down the line, cause many issues.

Through our extensive experience, we’ve found that even when Building Regulation Drawings aren’t legally mandated, they prevent costly errors and disputes. For example, a recent kitchen extension project saved our client £12,000 in potential remedial works because our detailed drawings identified a drainage issue before construction began.

For MCIAT professionals, these drawings serve as a vital communication tool between architects, structural engineers, contractors, and building control officers. They form part of the building contract and can protect you legally if construction disputes arise.

While some might suggest basic drawings suffice for smaller projects, our professional experience shows that comprehensive Building Regulation Drawings typically reduce construction costs by 5-15% through improved material specification and elimination of on-site decision making.

• Unlike basic plans, our Building Regulation Drawings include:
• U-value calculations for all thermal elements
• Detailed cavity tray and DPC positioning
• Precise specification of fire-rated materials
• Structural engineer’s calculations integration
• Full material specifications to building control standards

The real question isn’t whether you need Building Regulation Drawings, but rather what level of detail will best protect your investment and ensure full compliance with current regulations.

Planning drawings are what we call RIBA stage 3 conceptual drawings. They demonstrate what the project will look from the outside and its impact on the surrounding area. These drawings typically show elevations, site plans and basic floor plans with key dimensions to demonstrate the scale, appearance and location of the development. They may also include 3D visualisations or streetscape views to show how your project fits within its surroundings.

Building Regulations drawings are highly detailed technical drawings that show exactly how the project will be constructed. This is where a professional chooses the correct or most cost-effective materials to follow on from the grant of approval. For example, your planning permission drawings may have been attached to material conditions or specific ratings for inner rooms. Building regulations include construction details, structural calculations, material specifications, ventilation, insulation, drainage, fire safety measures and compliance with Part L (energy efficiency).

Building Regulations drawings include:

• Detailed construction drawings and specifications
• Wall, floor and roof construction details
• Structural calculations and beam sizes
• Drainage layouts and connections
• Fire strategy and escape routes
• Ventilation and heating systems
• Thermal calculations and SAP ratings
• Sound insulation details
• Access provisions
• Full material specifications

While planning focuses on visual appearance and local impact, Building Regulations ensure the development is structurally sound, safe, energy efficient and built to current standards. You’ll often need both types of approval for your project. Planning is obtained first, followed by detailed Building Regulations drawings once the design is approved. These drawings, depending on complexity, are then passed on to third parties such as quantity surveyors, who will produce a Bill of Quantities, or sent straight out for tender.

For high-rise buildings (7+ storeys or 18+ metres), Building Regulations drawings must now meet additional requirements under the new Building Safety Act, including more comprehensive fire safety information and maintenance of the “Golden Thread” throughout the building’s lifecycle. This includes detailed documentation of all safety-critical decisions and changes during design and construction.

To answer the question broadly, the simple answer is Yes. All Permitted Development projects require Building Regulations drawings, regardless of whether you need planning permission or not. This is a crucial distinction that many homeowners don’t initially realize.

Even when your project falls under Permitted Development rights, like a rear extension up to 6 metres, a loft conversion within 50 cubic meters, or a garage conversion, you must still submit detailed Building Regulations drawings. These technical drawings are essential for ensuring your construction meets all safety and building standards.

We must make a difference between obtaining grant of approval of planning permission and Building regulations these are two differently elements. Usually Architects will draw plans for planning permission only it does not mean they 100% accurate as this will be adjusted at the Detailed design stage (another name for Building Regulations Drawings) so it is vital you engage with a consultant to provide building regulations drawings.

The legal requirement for Building Regulations approval exists independently of planning permission. Without proper Building Control certification, your construction work is considered unauthorised, potentially leading to enforcement action and expensive remedial work.

Almost all the time when a property is sold, solicitors check for Building Control certificates. Missing documentation can significantly complicate or even prevent your property sale. Obtaining retrospective approval is substantially more expensive and complex than getting it right from the start.

From a practical perspective, detailed Building Regulations drawings help builders provide accurate quotes and prevent costly mistakes during construction. These drawings specify crucial details like foundation depths, structural calculations, insulation requirements, and fire safety measures.

This eliminates the common misconception that builders start with a lower price which then keeps increasing. Such price escalations often occur because there were no detailed drawings for builders to price from. Remember, one size doesn’t fit all – just because a previous house is similar, it doesn’t mean this particular house is the same. There may be issues with the soil or problems with heights where a qualified MCIAT professional will need to assess what to do to ensure all requirements are met. With updates in building regulations meaning new rules to adhere to, it’s imperative to get a professional to provide detailed building regulations drawings in London.

For specific projects under Permitted Development, the requirements vary. A single-storey extension needs drawings showing foundation details, wall construction, and drainage plans. Loft conversions require structural calculations for floor strengthening and detailed fire escape routes. Garage conversions must demonstrate adequate ventilation, damp proofing, and insulation specifications.

Building Regulations drawings will help save you from unforeseen costs, issues with coordination, and ensure you get approval from your chosen building control company.

This question varies dramatically depending on the type of works for example where there is multiple flats this may take longer it may go and fourth with consultations with the fire authority. However a general rule of thumb The Building Safety Regulator (BSR), Local Authority Building Control, or Approved Inspectors typically take 5-8 weeks to review and approve Building Regulations applications. Fast-track services are available in some areas, which can reduce this to 2-3 weeks.

Your Building Regulations application remains valid indefinitely once work has commenced and Building Control has been notified of the start. Remember to notify your building control body both when you start and complete the works.

For high-rise buildings (7+ storeys or 18+ metres), the process is now managed by the Building Safety Regulator under the new Building Safety Act, which may affect timelines.

It worth noting it best to get the project approved first before starting works, this is to ensure the principal designer is satisfied all consultants are satisfied with the work delivery and everything has been approved avoiding costly mistakes.

To deliver a safe and compliant design that meets the standards outlined in the Building Safety Act 2022.

To ensure all design work aligns with Building Regulations and supports effective construction, occupation, and long-term building management.

To establish and maintain a comprehensive Golden Thread of information for life safety and structural integrity.