Extending Your Home: How Far Can You Go?

A glazed extension is a popular way for homeowners to get more out of their property, providing a light and airy space that connects the interior and garden.

However, before you plunge ahead with your plans, it’s important to ensure that you aren’t inadvertently breaching the planning permissions which apply.

Wading through the technical wording can seem a bit daunting but our overview below highlights the most important points you need to bear in mind.

Is there a maximum size I can extend without needing planning permission?

Yes. Presuming it's a single-storey extension, you won’t be able to extend beyond a maximum of three metres (for terraced and semi-detached homes) or four metres (for detached homes).

This distance is measured from the original rear wall, regardless of what the structure looks like now.

This means the place where the rear wall stood when it was originally built or in the case of ambiguity in older properties, where it would have stood on 1st July 1948.

But I thought I could extend my home by 6 metres?

Planning permissions in England were relaxed on 1st June 2019, allowing single-storey extensions up to six metres (or eight metres for detached properties). This new rule only applies to glazed
extensions which are outside ‘Sites of Specific Interest’.

Will my neighbours be consulted before planning permission is granted?

Single-storey extensions which are bigger fall within the Neighbour Consultation Scheme.

This is often referred to as prior notification and gives your neighbour 21 days to raise an objection.

There must be valid reasons for their objection to succeed.

Once this initial 21-day period has elapsed, there is a further 21-day period for your local authority to confirm you are able to proceed.

If your extension requires planning permission, neighbour notification is mandatory.

What building regulations must a single-storey extension conform to?

Don’t confuse planning permission and building regulations; they’re not the same thing.

Planning permission is about the way development is carried out within an area, the general look and how the work will impact on the surrounding environment.

In contrast, building regulations specify standards that work must abide by in order to ensure the health, safety and well-being for those inside the property and others who live around it.

A glazed extension such as a conservatory, orangery or garden room may still require building regulations if any of the following apply:

• The roof is not at least 70% translucent
• The internal floor space exceeds 30 square metres
• There is less than 50% glass coverage on walls that have been newly constructed
• The extension is not at ground level
• There is no physical barrier that separates the extension from the main building, such as doors

Do I need planning permission to extend upwards?

Of course, not all extensions move outwards; some are upwards. From 31st August 2020 homeowners have been able to extend upwards without requiring full planning permission, but only
if certain criteria are fulfilled:

• The property must have been built between 2nd July 1948 and 29th October 2018
• Detached houses must have two or more storeys
• Terraced or semi-detached houses can only build to a maximum of 3.5 metres above the attached neighbours’ houses

Due to the potential impact on the surrounding homes, prior notification applies and building regulations must still be adhered to. Due regard must be given to the appearance of the extension.

To find out more about planning permission and building regulations, get in touch with us today.