Planning Permission Rules for Extensions in Kettering, Corby and Wellingborough (2025 Guide)

By L F Builders Ltd – Your local building specialists in Northamptonshire

Planning a home extension can be exciting, but navigating the planning permission rules across Northamptonshire—especially in areas like Kettering, Corby and Wellingborough—can feel confusing. The good news? Not every extension needs full planning permission.

However, the rules can vary depending on the size, layout, materials used, and whether the property is in a conservation or restricted area.

This guide breaks down everything homeowners need to know before starting an extension project in 2025.

Do You Need Planning Permission for a Home Extension?

Many standard extensions fall under Permitted Development Rights (PDR), meaning you don’t need planning permission as long as your project meets specific criteria.

To qualify for PDR:

1. The extension must not exceed certain size limits

• Rear extension:

  • Up to 3m deep on a semi-detached or terraced house

  • Up to 4m deep on a detached house

  • Larger “Neighbour Consultation Scheme” extensions (6m or 8m deep) may be possible but require the council to notify neighbours first.

• Side extension:

  • Must be single storey

  • Maximum height 4m

  • Must not be wider than half the width of the original house.

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2. Height restrictions apply

• Must not exceed the height of the existing roof.

• Single-storey extensions must be no higher than 4m overall.

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3. Materials should be similar

Extensions under PDR must use materials similar in appearance to the existing house unless otherwise approved.

4. Extensions cannot cover more than 50% of your outdoor garden/land

This includes any previous extensions or outbuildings.

Special Conditions in Kettering, Corby & Wellingborough

While the above rules apply nationally, your local council may apply stricter controls for certain areas.

Kettering

Kettering has several Article 4 Conservation Areas, including Montagu Street, Headlands, and Kettering Town Centre.In these zones:

• Permitted Development Rights may be restricted

• Any extension usually requires full planning permission

• Additional design guidelines may apply (materials, height, window style)

  
  

Corby

Corby Borough has seen significant growth and regeneration, meaning:

• Some new-build estates have developer restrictions (“covenants”)

• Conservation areas such as Corby Old Village impose stricter planning regulations

• Semi-detached and terraced extensions may have more neighbour-impact considerations

  
  

Wellingborough

Wellingborough contains several historic zones and older housing stock:

• Victorian terraces and listed buildings require special care

• Heritage impact statements may be required in some streets

• Rear extensions must consider light-impact on adjoining properties

  
  

When Planning Permission Is Required

You will likely need planning permission if:

• Your home is listed

• The property is in a conservation area

• You plan a two-storey extension

• The extension is close to a highway or alters the front appearance

• You live in a flat, maisonette, or converted property (PDR usually do not apply)

• Your proposed extension significantly affects neighbours’ privacy or light

  
  

What About Building Regulations?

Even if planning permission is not required, Building Regulations approval is always needed for structural work.

This ensures:

• Structural integrity

• Fire safety

• Proper drainage

• Energy efficiency

• Electrical safety

• Insulation and ventilation standards

  
  

L F Builders Ltd ensure full compliance by:

• Preparing and submitting plans where required

• Working closely with local building control teams

• Following all 2025 regulations and industry best-practice standards

• Only using qualified tradespeople for specialist work

  
  

How Long Does Planning Permission Take?

• Standard applications: 8 weeks

• Larger/more complex projects: up to 13 weeks

• Neighbour Consultation Scheme (for extended rear extensions): 42 days

  
  

How Much Does Planning Permission Cost?

As of 2025:

• Householder planning application fee: £258

• Lawful Development Certificate (to confirm PDR compliance): £129

  
  

Many homeowners choose the Lawful Development Certificate option even when full permission isn’t required—because it adds legal protection when selling the house.

How L F Builders Can Help

We provide a complete extension service throughout Kettering, Corby, Wellingborough and the wider Northamptonshire area, including:

• Free on-site consultation

• Advice on planning permission requirements

• Architectural drawings and planning submissions

• Full building regulation compliance

• Fixed, detailed quotes

• Transparent communication throughout your project

Whether you're planning a small side extension or a large two-storey remodel, our team ensures your project is fully compliant and stress-free from start to finish.

Planning an Extension? Let’s Get Your Project Started

Contact us today to arrange a free, no-obligation consultation.

📞 07810 635504📍 Serving Kettering, Corby, Wellingborough & all surrounding Northamptonshire villages🌐 www.lfbuildersltd.co.uk