Can I Start Building Before Building Regulations Approval Is Granted?
Short answer: Technically, yes—but it is usually a very bad idea.
Many homeowners assume that once planning permission has been granted, they can immediately start construction. However, planning permission and Building Regulations approval are two completely separate processes. Starting work before your Building Regulations drawings have been approved can lead to costly delays, expensive remedial works, and difficulties when selling your property in the future.
In this guide, we explain when you can start work, the risks involved, and why obtaining Building Regulations approval before construction begins is almost always the safest option.
Planning Permission and Building Regulations Are Different
One of the most common misconceptions among homeowners is that planning permission automatically allows construction to begin.
Planning permission focuses on matters such as:
Appearance and design
Impact on neighbours
Size and scale
Conservation areas
Local planning policies
Building Regulations, on the other hand, deal with:
Structural safety
Fire safety
Insulation and energy efficiency
Ventilation
Drainage
Accessibility
Electrical and mechanical systems
Even if your planning application has been approved, you will usually still need Building Regulations approval before carrying out construction work.
If you're unsure whether your project requires approval, read our guide to Building Regulations Drawings:
https://www.drawandplan.com/building-regulations-drawings
Can You Legally Start Work Before Approval?
Under the Building Regulations system, it is possible to commence work before Full Plans approval has been formally issued.
However, this does not mean your proposals have been approved.
The Building Control officer may later review the drawings and require significant changes to work that has already been completed.
This can result in:
Demolition of newly built elements
Additional structural work
Delays on site
Increased construction costs
Disputes with contractors
For this reason, most experienced designers and builders recommend waiting until approval has been obtained.
You can read the government's Building Regulations guidance here:
https://www.gov.uk/building-regulations-approval
The Risks of Starting Too Early
Structural Issues
Building Control may require additional steel beams, foundations, or structural alterations once calculations have been reviewed.
If construction has already progressed, these changes can be difficult and expensive to implement.
Insulation and Energy Compliance
Part L of the Building Regulations sets minimum standards for thermal performance.
If wall, roof, or floor constructions do not achieve the required U-values, completed work may need to be altered.
Fire Safety Problems
Fire safety requirements can affect:
Escape windows
Loft conversion stairs
Fire doors
Smoke alarm systems
Structural fire protection
Changes introduced after construction has started can be disruptive and costly.
Drainage and Ventilation Issues
Drainage layouts and ventilation systems often require careful coordination before work begins.
Late design changes can involve opening up completed construction and re-routing services.
What Happens If Building Control Rejects Part of the Design?
If Building Control identifies non-compliant work, they can require corrective measures before issuing a Completion Certificate.
Without a Completion Certificate, homeowners may experience difficulties when:
Selling their property
Remortgaging
Obtaining indemnity insurance
Demonstrating compliance to future buyers
The cost of remedial work is often significantly greater than the cost of obtaining proper Building Regulations drawings in the first place.
What Is the Best Approach?
The safest route is:
Complete detailed Building Regulations drawings.
Obtain structural calculations where required.
Submit the package to Building Control.
Receive approval.
Start construction.
This provides certainty for both homeowners and contractors and reduces the risk of unexpected site changes.
For a step-by-step overview of the design process, see:
https://www.drawandplan.com/services-prices
How Long Does Building Regulations Approval Take?
Approval times vary depending on the complexity of the project and the Building Control provider.
For many residential extensions and loft conversions, approvals are typically received within a few weeks, provided the drawings contain sufficient information and any queries are addressed promptly.
Preparing a comprehensive Building Regulations package from the outset can significantly reduce delays.
Frequently Asked Questions
Can I start foundations before Building Regulations approval?
Technically, yes, but it is risky. If Building Control later requires deeper foundations or alternative structural solutions, completed work may need to be altered.
Can I start internal alterations before approval?
Minor work may be possible, but proceeding without approved drawings can still create compliance issues later.
Is planning permission enough to begin construction?
No. Planning permission and Building Regulations approval are separate requirements.
What happens if I build without Building Regulations approval?
You may face enforcement action, expensive remedial works, and difficulties obtaining a Completion Certificate.
Need Building Regulations Drawings?
At Draw & Plan, we prepare detailed Building Regulations drawings for extensions, loft conversions, renovations and new-build homes throughout London and the South.
Our drawings are designed to help achieve approval quickly while giving builders the information they need to construct the project correctly and efficiently.
Contact us today:
https://www.drawandplan.com/contact-us
Disclaimer: This article is for general informational purposes only and does not constitute legal or professional advice. Always consult relevant professionals and local authorities before undertaking any development or change of use
