Full Plans Application or Building Notice?

There are different routes for dealing with Building Regulations approval.

 

Full Plans Application

A full-plans application is usually the most suitable route for a house extension.
 

Detailed drawings and supporting information are submitted before or during the early stages of the project.
 

The plans are reviewed and, where acceptable, an approval notice is issued.
 

This approach gives the homeowner and builder a clearer understanding of the technical requirements before construction progresses too far.
 

It can also help identify issues before they become expensive problems on site.

 

Building Notice

A building notice may be available for some smaller domestic projects.
 

This route allows work to begin shortly after the notice has been submitted, but the detailed plans are not formally approved in advance in the same way.
 

The builder must still ensure that the work complies with the Building Regulations.
 

For a straightforward alteration, this approach may be appropriate.
 

For a more substantial extension, a full-plans application is often preferable because it provides greater clarity before construction begins.

 

Who Approves the Work?

For most domestic house extensions in England, the homeowner can choose between:
 

• The local authority Building Control department

• A private registered building control approver
   

The chosen building control body will review the relevant information and inspect the work at appropriate stages.
 

The builder should coordinate inspections as the project progresses.

 

What Site Inspections Are Required?

Building Control will normally inspect the work at several stages.
 

The exact sequence will depend on the project, but inspections may include:
 

• Excavation before foundations are poured

• Completed foundations

• Drainage before it is covered

• Ground-floor construction

• Damp-proof course

• Structural steelwork

• Roof construction

• Insulation

• Fire-safety measures

• Completion
   

Do not cover important work before the relevant inspection has taken place.
 

The builder should allow for the inspection process within the construction programme.

 

Do I Need a Structural Engineer?

Many extensions require a structural engineer.
 

You are particularly likely to need structural calculations if the project involves a wide opening between the original house and the new extension.
 

This is common where homeowners want a large kitchen, dining and family room.
 

The engineer may specify:
 

• Steel beams

• Columns

• Padstones

• Connections

• Foundation details

• Roof structure

• Temporary support requirements

• Structural calculations
   

The structural engineer and the designer should coordinate their information so that the builder receives a clear package.

 

Can I Start Building Before Approval?

The answer depends on the type of application.
 

However, it is usually sensible to prepare the technical information before substantial work begins.
 

Starting too quickly can create avoidable risks.
 

For example:
 

• The foundations may need to be deeper than expected

• A drain may need to be diverted

• The proposed steel beam may need to change

• The insulation design may not satisfy the requirements

• The glazing area may be excessive

• A roof detail may need to be redesigned
   

Resolving these issues on paper is usually easier and cheaper than making changes after construction has started.

 

What Happens When the Extension Is Complete?

Once the work has been completed and the necessary inspections have taken place, the building control body should issue the relevant completion certificate where the work complies.
 

Keep this certificate safely.
 

It may be important when you sell or remortgage the property.
 

The completion certificate provides evidence that the work has been inspected through the Building Control process.

 

What If I Build Without Approval?

Carrying out work without the appropriate Building Regulations process can cause serious problems.
 

You may face:
 

• Difficulty selling the property

• Questions from solicitors and mortgage lenders

• The cost of opening up completed work for inspection

• Remedial work

• Additional professional fees

• Delays

• Enforcement action

• Disputes with builders
   

Retrospective approval may sometimes be possible through a regularisation application, but this is not the best way to approach a new extension.
 

It is far better to deal with the requirements properly before work begins.
 

Building Regulations Approval Does Not Replace Other Permissions

Building Regulations approval is only one part of the process.
 

Depending on the project, you may also need:
 

• Planning permission

• Confirmation of permitted development rights

• A lawful-development certificate

• Party Wall notices

• A Party Wall Award

• A build-over agreement

• Freeholder consent

• Leaseholder consent

• Listed-building consent

• Conservation-area advice

• Specialist structural advice
   

Each issue should be considered separately.

 

Prepare the Technical Details Before You Build

A well-designed extension needs more than an attractive layout.
 

The construction details, structural calculations, drainage arrangements, insulation and Building Control process all need to work together.
 

Preparing a proper Building Regulations package can help builders quote more accurately, reduce uncertainty on site and give the project a stronger foundation from the outset.

 

Find the Right Support for Your Extension

Depending on your project, you may need architectural design support, Building Regulations drawings, structural calculations, Building Control input, Party Wall advice and an experienced extension builder.
 

Tell us a little about your property, the extension you are considering and the stage you have reached. We can help connect you with suitable professionals for the next steps.