Yes, for most extensions, garage conversions and structural alterations in England and Wales, you will need building regulations drawings or equivalent information to show your project complies. These drawings prove to building control how the work meets the Building Regulations 2010, and they’re what allow the inspector to issue the completion certificate you’ll need for future resale or remortgaging.
TL;DR:
- A full plans application gives you a formal decision before work begins; a building notice suits simpler jobs but leaves more compliance risk later.
- A complete submission needs site and floor plans, elevations, sections, structural calculations where needed, drainage and ventilation details, insulation junctions, and a compliance statement.
- Use 1:50 or 1:100 for plans and elevations, but show complex junctions at 1:20 or 1:10; loadbearing changes need a structural engineer’s calculations.
- For full plans, the local authority should decide within five weeks of receiving the application, unless the parties agree in writing to an extension.
- Building control issues a completion certificate after inspections, and conveyancers commonly request it; missing paperwork can delay a sale or mortgage application.
Table of Contents
- What building regulations drawings are and when you need you them
- What a full plans pack usually contains
- How detailed do the drawings need to be?
- Who prepares the drawings, and what do they cost?
- How to submit drawings and why the completion certificate matters
- Our checklist for North West homeowners starting this process
- Why precise drawings save money and stress
- How we help with building regs drawings and approvals
- FAQ
- Sources
What building regulations drawings are and when you need you them
Building regulations drawings are the technical plans that show how your project will meet the Building Regulations 2010, covering structure, fire safety, insulation, ventilation and drainage. They’re separate from planning permission drawings, which deal with appearance and land use rather than construction detail.
Most home building projects fall under one of two routes. A full plans submission means detailed drawings and calculations go to the council or an approved inspector before work starts, and you get a formal decision. A building notice is a simpler route where you tell the council you’re starting work, but it carries more risk if something doesn’t comply later. According to Planning Portal guidance, building control approval is required for most structural alterations, extensions and conversions.
Projects that typically need building regulations drawings include:
- Single-storey and two-storey house extensions
- Garage conversions into habitable rooms
- Removing or altering loadbearing walls, including new RSJ installations
- Conservatory roof replacements where structural work is involved
What a full plans pack usually contains
A council or approved inspector will expect a complete pack, not just a sketch of the new layout. Each document proves a different part of compliance, from how the building sits on the plot to how loads travel through the structure.
- Site plan showing the property boundary and the new build’s position
- Existing and proposed floor plans with room uses and dimensions
- Elevations and cross sections showing heights, roof pitches and floor build-ups
- Structural calculations for any loadbearing work, steel beams or foundations
- Drainage and ventilation drawings, including falls and connection points
- Thermal and insulation details at junctions such as walls, floors and roofs
- A building regulations compliance statement linking each drawing to the relevant approved document
Official Gov recommends uploading clearly labelled drawings alongside a compliance statement that ties them to the specific functional requirements they satisfy, which helps the building control officer find what they need without back-and-forth queries.
Pro Tip: Number every drawing and keep a one-page index with a short description of each sheet. It saves days when building control asks a follow-up question.
How detailed do the drawings need to be?
Scale matters more than most homeowners expect. A site plan usually sits at 1:1250 or 1:500, floor plans and elevations at 1:50 or 1:100, and tricky junctions such as a steel beam bearing or a new foundation detail need to be drawn at 1:20 or 1:10 so the inspector can see exactly how materials meet.
Building control officers tend to focus on a handful of details every time:
- Structural connections, such as how a new beam transfers load to a wall or padstone
- Fire separation between a garage conversion and the rest of the house
- Insulation continuity at wall, floor and roof junctions
- Drainage falls and connections to existing systems
A simple single-storey extension with standard foundations might only need a competent designer’s drawings. The moment you’re removing a loadbearing wall, extending at two storeys, or dealing with poor ground conditions, you’ll need a structural engineer’s calculations alongside the architectural drawings.
Who prepares the drawings, and what do they cost?
Different professionals handle different parts of the pack. An architect or building designer produces the layout drawings, elevations and sections. A structural engineer calculates loadbearing work such as beams, foundations and openings. Building control, whether the local authority or an approved inspector, reviews everything and carries out site inspections.
Costs vary by project size and complexity, but realistic UK bands for a typical single-storey extension include:
- Architectural drawings for a straightforward single-storey extension: typically costing several hundred to a couple of thousand pounds
- Structural engineer’s calculations: generally several hundred pounds depending on project complexity
- Building control fees: often a few hundred pounds for a standard domestic extension, with higher fees for larger or more complex projects
One of the most consistent factors in cost is scope: a project with unusual ground conditions, listed building constraints or a complicated roof line will push fees towards the top of these ranges, because it demands more calculation and more detailed drawing work.
When commissioning drawings, ask what’s included in the price, whether structural calculations are covered, and whether the quote includes liaison with building control. A fixed-price quotation that bundles these stages together tends to be easier to compare than several separate quotes from different professionals.
How to submit drawings and why the completion certificate matters
Submitting is straightforward once your pack is ready, though the steps matter.
- Choose your route: deposit full plans for a formal decision before work starts, or submit a building notice if you’re confident the project is simple and compliant.
- Submit the pack: drawings, calculations and the compliance statement go to your local authority or approved inspector.
- Wait for the decision: for a full plans application, the local authority should respond within five weeks of receipt, extendable by written agreement.
- Arrange inspections at key stages, such as foundations, damp-proofing and completion.
- Receive your completion certificate, the official record that the finished work complies.
That certificate matters well beyond the build itself. It’s commonly requested during conveyancing, and its absence can delay a sale or a mortgage application further down the line.
Our checklist for North West homeowners starting this process
Before your first meeting with a designer, bring rough measurements, your title plan, photographs of the affected area, and a clear idea of scope and budget. It makes the first conversation far more productive.
We coordinate the drawings, structural checks and building control submission as one managed process rather than separate appointments, which avoids the gaps that cause delays. Local considerations we handle regularly include:
- Party wall enquiries for extensions close to a boundary
- Drainage connections and ties into existing systems
- Current energy efficiency expectations for new walls, floors and glazing
Why precise drawings save money and stress
We’ve seen enough projects stall over vague drawings to know that a missing detail on site almost always costs more to fix than it would have cost to draw properly the first time. We treat the drawing stage as the foundation of a smooth build, not a formality to rush past.
— Gareth
How we help with building regs drawings and approvals
We manage the whole process for you, from initial design through structural checks to building control liaison, so you’re not juggling separate professionals and crossed wires. A typical fixed-price package covers:
- Design and drawings tailored to your project
- Structural calculations where loadbearing work is involved
- Submission and liaison with building control through to completion
When comparing quotes, ask whether structural calculations, building control liaison and site inspections are included, so you’re comparing like for like. 
If you’re planning an extension or structural alteration anywhere across our North West coverage area, get in touch and we’ll talk through what your project needs: explore our house extensions service.
FAQ
Do I need architect drawings for planning permission?
Not always. Planning permission drawings can often be produced by a building designer rather than a qualified architect, and some smaller projects fall under permitted development with no planning application needed at all. Building regulations drawings, which cover construction detail and compliance, are a separate requirement and are usually needed regardless of planning status.
What is the standard sequence of architectural drawings?
A typical sequence runs from a site plan, through existing and proposed floor plans, to elevations and cross sections, finishing with detailed junction drawings for anything structurally complex. Structural calculations and a compliance statement are usually added once the layout is confirmed.
Are drawings protected by copyright?
Yes, architectural and technical drawings are generally protected by copyright, which sits with the designer or firm that produced them unless otherwise agreed in writing. It’s worth clarifying ownership and usage rights when you commission drawings, particularly if you later want to reuse them or switch contractors.
How do I apply for building regulations approval in the UK?
You can either deposit full plans for a formal decision before starting work, or submit a building notice if you’re confident the project is simple and compliant. For a full plans application, the local authority should issue a decision within five weeks of receiving your submission, though this period can be extended by written agreement.
Sources
- Gov
- Planning Portal — When you need building control approval
- Designing Buildings — Full plans application
- The Building Regulations 2010 (SI 2010/2214) — Part 3: Notices, plans and certificates
