Resource guide | 8 min read
Building Regulation Drawings Guide — What Homeowners Need to Know
Building regulation drawings are the technical documents that show how a building project will be constructed in compliance with the Building Regulations 2010. This guide explains what these drawings include, how they differ from planning drawings, who approves them, what the approval process involves, and what UK homeowners can expect to pay.
What Are Building Regulation Drawings?
Building regulation drawings (also called building regulation plans or working drawings) are detailed technical documents that show how a building project complies with the Building Regulations 2010 and associated Approved Documents.
Unlike planning drawings, which show what a project will look like, building regulation drawings show how it will be built — including structural details, fire safety, insulation, drainage, and accessibility provisions.
You need building regulation drawings for most structural building works, including:
- House extensions
- Loft conversions
- Garage conversions
- New builds
- Structural alterations (removing walls, adding beams)
- Changes of use
- Basement conversions
Planning Drawings vs Building Regulation Drawings
Many homeowners confuse planning permission drawings and building regulation drawings. They are different documents for different purposes.
Planning drawings show what you plan to build and are submitted to the local planning authority to obtain planning permission. They typically include floor plans, elevations, and site plans at scales of 1:100 or 1:200.
Building regulation drawings show how you will build it and are submitted to a building control body to obtain building control approval. They include structural details, insulation, drainage, and fire safety information, usually at scales of 1:50 or 1:20 for details.
You usually need both sets of drawings for projects requiring planning permission. Some projects (e.g. permitted development extensions) may only need building regulation drawings.
What Do Building Regulation Drawings Include?
A full building regulation drawing package covers several technical areas, each addressing a specific aspect of the Building Regulations.
Architectural Drawings
The architectural set establishes the layout and dimensions of the works.
- Floor plans showing room dimensions, wall thicknesses, openings
- Elevations showing heights, window positions, roof pitches
- Sections showing internal construction details
- Roof plans
Structural Drawings and Calculations
Structural drawings and accompanying calculations demonstrate compliance with Part A (Structure).
- Foundation details (type, depth, concrete specification)
- Beam and column sizes and specifications
- Structural calculations signed by a structural engineer
- Load paths and point loads
- Steelwork connections
- Temporary works notes where relevant
Thermal and Energy Compliance
Thermal information demonstrates compliance with Part L (Conservation of fuel and power).
- U-value calculations for new walls, roof, and floors
- Window and door energy ratings
- Overheating risk assessment
- SAP/SBEM energy performance calculations (for new builds)
- Thermal bridging details
Fire Safety
Fire safety provisions are set out under Part B.
- Escape routes from each room
- Fire door positions and ratings
- Smoke alarm/heat detector positions
- Sprinkler provision (where required)
- Cavity barriers and fire stopping details
Drainage and Plumbing
Drainage details satisfy Part H requirements.
- Foul water drainage routes
- Surface water drainage
- Rainwater harvesting (where included)
- Soil and vent pipe positions
Accessibility (Part M)
Accessibility provisions demonstrate compliance with Part M.
- Step dimensions and handrail provision
- WC dimensions where required
- Accessibility provisions for visitability
Ventilation
Ventilation details demonstrate compliance with Part F.
- Background ventilation (trickle vents or equivalent)
- Extract ventilation in kitchens and bathrooms
- Whole house ventilation where required
Who Approves Building Regulation Drawings?
Building regulation drawings must be approved by a building control body. There are two options.
For most residential projects, local authority building control is used. From April 2024, under the Building Safety Act 2022 reforms, the regime changed for Higher Risk Buildings — your architect or building control officer can advise if your project is affected.
1. Local Authority Building Control (LABC)
Your local council's building control department. Applications go through the Planning Portal or directly to the council.
2. Approved Inspector (Private Building Control)
A private building control inspector registered with the Construction Industry Council (CIC). Approved inspectors can sometimes process applications more quickly.
The Building Regulation Approval Process
The full plans application route involves several stages, from appointment of professionals through to a Completion Certificate at the end of works.
Step 1: Appoint an Architect or Structural Engineer
For any structural project, you need a professional to prepare detailed drawings. For projects involving structural alterations or new structural elements, a structural engineer's calculations are required.
Crown Architecture prepares both architectural drawings and structural calculations in-house, removing the need to appoint separate consultants.
Step 2: Prepare the Full Drawing Package
The drawing package is submitted with a Building Regulations application (Full Plans Application). This is the recommended route for most projects as it gives you formal approval before work starts.
Alternatively, a Building Notice can be used for smaller projects — no drawings are submitted in advance, but the building control officer inspects work in progress. This carries more risk if problems are found on site.
Step 3: Submit the Application
Applications are submitted to the building control body with the required documentation and fee.
Fees are set by the local authority and vary by project size.
- Completed application form
- Full set of building regulation drawings
- Structural calculations (where applicable)
- Application fee
Step 4: Plan Check
Building control will check the drawings for compliance with the relevant Approved Documents. They may raise queries or request amendments.
Step 5: Approval (or Conditional Approval)
Most full plans applications receive an approval or conditional approval within 5 weeks (extendable to 2 months with agreement).
Step 6: Site Inspections
Even after drawings are approved, building control will carry out site inspections at key stages:
- Commencement of works
- Foundation excavation
- Concrete pour
- Damp proof course
- Structural frame/beams
- First fix (electrical, plumbing)
- Roof structure
- Insulation
- Completion
Step 7: Completion Certificate
On satisfactory completion, building control issues a Completion Certificate. This is an important document — you will need it when you sell the property and your solicitor's searches will look for it.
Common Building Regulation Approved Documents
The Building Regulations are supported by Approved Documents that give practical guidance. The most commonly referenced parts for residential works are:
- Part A — Structure
- Part B — Fire safety
- Part C — Site preparation and resistance to contaminants
- Part D — Toxic substances
- Part E — Resistance to sound
- Part F — Ventilation
- Part G — Sanitation, hot water safety and water efficiency
- Part H — Drainage and waste disposal
- Part J — Combustion appliances and fuel storage
- Part K — Protection from falling, collision and impact
- Part L — Conservation of fuel and power
- Part M — Access to and use of buildings
- Part N — Glazing safety
- Part O — Overheating
- Part P — Electrical safety
- Part Q — Security
- Part R — High-speed electronic communications networks
- Part S — Infrastructure for charging electric vehicles
How Much Do Building Regulation Drawings Cost?
Building regulation drawing costs vary depending on project complexity and what's included. Typical drawing cost ranges for common residential projects are:
- Single-storey rear extension: £600–£1,500
- Double-storey extension: £900–£2,500
- Loft conversion: £800–£2,000
- Garage conversion: £400–£900
- Internal structural alteration: £400–£1,200
- Structural calculations — simple steel beam: £200–£500
- Structural calculations — complex multi-beam or foundation design: £500–£2,000+
Integrated Pricing
Structural calculations are usually charged separately if a structural engineer is involved. Crown Architecture provides integrated architectural drawings and structural calculations with no need to appoint separate consultants.
What Happens if You Build Without Building Regulations Approval?
Building without required building regulations approval is a criminal offence. If you build without approval and it is discovered, several consequences can follow.
Some homeowners try to regularise work after the fact with a Regularisation Certificate, but this requires the building control officer to inspect and may require opening up work to check compliance.
Always obtain proper approval before starting structural works.
- The local authority can issue an enforcement notice requiring you to undo the work.
- You may face a fine.
- When you come to sell the property, your solicitor will find that no completion certificate exists, which can cause a sale to fall through.
- Your insurance may not cover work done without building regulations approval.
Building Regulations for Common Project Types
Different project types have different building regulation focus areas. Below is a summary of the main considerations for typical residential works.
Rear Extension
Every rear extension needs building regulation drawings covering: foundations, structural frame (if steel), external wall construction, roof construction and insulation, windows and doors, drainage, and fire safety.
Loft Conversion
Loft conversions are complex from a building regulation perspective, requiring: structural floor design, staircase design, fire safety (including protected escape routes), thermal insulation, and window ventilation.
Garage Conversion
Converting a garage to a habitable room requires: thermal upgrades to walls, floor, and ceiling, dampproofing, ventilation, and electrical work.
Structural Alterations (Wall Removal)
Removing a load-bearing wall requires a structural engineer to specify the replacement beam, its connections, and any point load provisions — all of which must be shown on building regulation drawings.
Related routes
Continue to the service pages most relevant to this topic
These links move readers from research into the service pages that best match the project stage they are in now.
Building regulation drawings
Technical drawing packages for building control approval.
Architectural drawings
Planning and building regulation drawing packages for homeowner projects.
Structural engineer
Structural calculations coordinated with the drawings.
Project pricing
Indicative fees for typical residential drawing packages.
FAQ
Questions homeowners often ask next
Do I always need building regulation drawings?
Not always. Some minor works, such as replacing like-for-like windows or fitting a new bathroom without structural changes, may not require formal approval. Your architect or building control officer can advise whether your specific project needs a building regulations application.
Do I need both planning permission and building regulations?
Planning permission and building regulations are separate processes. Some projects need both, some need only planning permission, and some need only building regulations. Many projects carried out under permitted development still need building regulations approval even though planning permission is not required.
Can I use the same architect for both planning and building regulation drawings?
Yes, and it is usually more efficient to do so as the architect understands the project throughout. Crown Architecture handles both the planning and building regulation stages as part of a single service, which reduces duplication and coordination problems.
How long does building regulation approval take?
A full plans application typically takes 5 weeks, extendable to 2 months by agreement with the building control body. The building control officer will notify you when drawings are checked or if queries arise.
Can I start work before getting building regulation approval?
Starting work before full plans approval is not recommended. If you use a building notice route instead, you can start work, but this carries risk if the building control officer identifies problems during inspections that then require remedial work on site.
What is a Completion Certificate and why does it matter?
A Completion Certificate is issued by building control once works are signed off as compliant with the Building Regulations. It is an important document for future property sales — your solicitor's searches will look for it, and missing certificates can delay or jeopardise a sale.
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Crown Architecture & Structural Engineering Ltd prepares integrated architectural drawings and structural calculations for extensions, loft conversions, and structural alterations across London and the South East. Call +44 7950 114633 or email info@crownarchitecture.co.uk for a fixed-fee quote and indicative timeline.