If you’re planning an extension, loft conversion, or other home improvement, you’ll almost certainly come across two terms that cause confusion: planning permission and building regulations.
Many homeowners assume they are the same thing — or that one replaces the other. In reality, they are two separate approval processes, and misunderstanding the difference can lead to delays, extra costs, or even enforcement action.
At Your Plans UK, we guide clients through both processes every day. In this article, we explain what planning permission and building regulations are, how they differ, and why most projects need both.
What is planning permission?
Planning permission controls how developments affect the surrounding area. It is governed by your local planning authority and focuses on issues such as:
- The size, height, and appearance of a development
- Impact on neighbours (loss of light, privacy, outlook)
- Design, materials, and character of the area
- Parking, access, and highways considerations
In simple terms, planning permission asks: “Is this development acceptable in this location?”
What is permitted development?
Many residential projects fall under permitted development (PD) rights, meaning formal planning permission may not be required. Common examples include:
- Single-storey rear extensions within size limits
- Certain loft conversions
- Small outbuildings
However, permitted development is subject to strict rules, and rights can be removed if:
- The property is in a conservation area
- The house has already been extended
- A planning condition restricts development
For this reason, many homeowners apply for a lawful development certificate to confirm their proposal is permitted.
What are building regulations?
Building regulations deal with how a building is constructed, rather than how it looks or affects neighbours. They ensure that all building work is:
- Structurally safe
- Energy efficient
- Fire safe
- Accessible
- Properly ventilated and insulated
Building regulations approval asks a different question to planning: “Is this building safe and built correctly?”
What do building regulations cover?
Building regulations apply to almost all construction work, including projects that don’t need planning permission. They cover areas such as:
- Foundations and structural stability
- Walls, roofs, and insulation
- Fire escape routes and smoke detection
- Drainage and water supply
- Electrical and ventilation standards
Approval is usually granted through building control, either via the local authority or an approved inspector.
Do you need both planning permission and building regulations?
In many cases, yes — you need both.
For example:
- A rear extension may require planning permission and building regulations approval
- A permitted development extension may not need planning permission but will still require building regulations approval
A common mistake is assuming that if planning permission isn’t required, building regulations aren’t either — this is not the case.
What happens if you ignore one or the other?
Failing to obtain the correct approvals can lead to serious consequences, including:
- Enforcement action by the council
- Difficulty selling the property
- Problems with mortgage lenders or insurers
- Costly remedial work
Building without building regulations approval is particularly risky, as safety issues may only become apparent years later.
How the processes work together
Although planning permission and building regulations are separate, they work best when considered together at the design stage.
At Your Plans UK, we design projects that:
- Meet planning policy and local authority expectations
- Comply with building regulations from the outset
- Avoid redesigns later in the process
This joined-up approach helps keep projects on track and within budget.
How Your Plans UK can help
Your Plans UK provides a full design service to support both approvals, including:
- Feasibility advice before you apply
- Planning drawings and applications
- Building regulations drawings
- Ongoing guidance through the approval process
We explain requirements clearly and help you understand what approvals you need and why, before any work starts on site.
Unsure which approvals your project needs?
If you’re planning an extension, loft conversion, or renovation and aren’t sure whether you need planning permission, building regulations approval, or both, get in touch with Your Plans UK. We’ll review your proposals and provide clear, practical advice tailored to your property. Contact us here today here for a free initial consultation.