Frequently Asked Questions

A kitchen extension is an investment in your home, so you likely have a few questions before you get started. Over the years we have worked on a vast range of extension projects. As a result, we can advise on every aspect of the design, planning and construction process.

Below you will find some common questions asked by our clients. If you have any further questions, our team of experts are more than happy to help. So feel free to contact us or give us a call on 0800 917 7127.

How long does an extension take?

A standard extension from Plus Rooms usually takes between 8 and 10 weeks for the initial build, with a further 6 to 8 weeks to install all required facilities and add those important finishing touches.

Can you extend an extension?

While it is certainly possible to extend an existing extension, it can be a complex process depending on the age, size and design of the current extension. More often than not, it is simpler and more cost-effective to simply demolish the old extension and start from scratch.

Does a kitchen extension add value?

Generally speaking, a kitchen extension will add value to your property. This recent article from Uswitch estimates that an extension in the London area will add up to £3k per m2. However, we strongly recommend that you speak to an estate agent in your area before estimating the added value of your extension.

How much does an extension add to the value of a house?

Many variables can affect how much value an extension adds to your home, such as the size and age of the extension, not to mention the location of your property. Again, we advise you to consult with an experienced local estate agent before assigning a monetary value to your extension.

How close to my boundary can I build an extension?

You have a legal right to build up to the boundary line of your property, subject to planning permission and complying with all requirements of the Party Wall Act 1996.

What size extension can you build under permitted development?

Permitted development guidelines for extension size can vary based on the type of property you are extending. As a general estimate, the maximum extension size is 3m for terraced and semi-detached houses and 4m for detached properties.

What is the maximum extension without planning permission?

If you do not obtain planning permission, the maximum extension size is 6m for terraced and semi-detached properties and 8m for detached properties. This would need to be approved under Prior Approval, which is an extension of Permitted Development rights. You can learn more about this by visiting our planning services page.

When do you need planning permission for an extension?

You need planning permission for an extension when the size or design of the extension exceeds the provisions of Permitted Development or Prior Approval. However, if you live in a flat or your property is located in a conservation area (an area with significant historical or architectural interest), you will usually have to apply for planning permission regardless of the size or design of the extension.

How long does planning permission take for extension?

Once you’ve submitted your application to your local authority, the process usually takes 8 weeks. However, you should also allow between 6 and 8 weeks to prepare and submit plans. Overall, we advise instructing your architect or construction company at least 4 months before your ideal start date.

How far can you extend a semi-detached house?

Under permitted development you can extend a semi-detached property by up to 3m, this increases to 6m under Prior Approval. However, you could potentially extend your house further subject to local authority approval.

Need help refining your house extension ideas into a single, cohesive vision? Why not browse our bespoke kitchen extensions? If you’ve got any questions, contact Plus Rooms today.

Kitchen Extension Projects

Kylemore Rd

West Hampstead

Beauval Rd

East Dulwich

Braemar Ave


Bromar Rd


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Tulse Hill

Dassett Rd

West Norwood

Lime Grove


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Revelstoke Rd


Shawbury Rd

East Dulwich

Shenley Rd


Upland Rd 2

East Dulwich

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