Call Free: 0800 334 5774
Call Free: 0800 334 5774

Granny Annexe Extensions

Category Archives

Differences between a granny annexe and an annexe extension

We are proud to offer a number of solutions for our customer’s annexe housing needs. These solutions might depend on the type of land you have, the size of your garden and particular building regulations for that area.

An annexe building in the garden is usually the preferred solution for people wanting to build a separate home for relatives within the grounds of their house, but sometimes a number of factors might affect if you can build an annexe or not.

In some rare cases when an annexe design has been refused by building control, a solution could be to opt for an extension instead. Our extensions have some advantages over our more traditional garden annexes, whilst still being built with the same SIP technology. A single storey extension can often be built under permitted development as long as it meets a certain set of credentials.

Below is an example of some of the criteria that are required for ‘permitted development for enlargement’ to be allowed. (Other criteria might apply)

  • The total area of ground covered by the extension (not including the original dwelling) is not more than 50% of the garden, not including the ground covered by the original dwelling house
  • The hight of the extension does not exceed the height of the original dwelling house
  • The height of the eves of the extension wouldn’t exceed the height of the eves of the original dwelling house
  • The single-storey rear extension does not extend beyond the rear wall of the original house by more than 6 metres if an attached house or by 8 metres if a detached house
  • The maximum height of a single-storey rear extension should not exceed four metres
  • Materials to be similar in appearance to the existing house


In most cases, a single storey extension can be built within permitted development and might succeed in gaining permission when an annexe does not.


What are the differences between a Granny Annexe and our extensions?




Apart from the obvious difference that one is an auxiliary building and the other an extension joined to the main building, the differences in terms of how the two buildings are used are very small.

Both buildings can function as a separate home for the occupants, with each having its own individual access. Both can also have its own kitchen and separate bedroom. The only real difference is that an extension is linked to the house. This can also reduce the costs of groundworks and services such as laying pipes or connecting electricity.

Another advantage of building an ‘annexe extension’ over a more traditional garden building is that the resulting building is incredibly versatile. For example, it can be incorporated into the main house at a later stage if the property was sold and subsequently turned into a kitchen or living area extension. This can have advantages over a ‘normal’ annexe located separately from the main building, that might not be so versatile in later years. This could also increase the value of your overall home by a higher margin, compared to a similarly sized annexe built in the garden.

Another obvious advantage with an extension over a separate building is when you are limited for space in your garden. An annexe normally requires you to have at least 50 cm space between the boundary and the building, this can mean in a small garden, space is very limited. An extension can be built closer to the boundary when it is attached to the main building meaning that this could afford you a larger building.

It also clear that if you have a small garden then building an annexe might not be possible at all.




Our extensions are built with all of these factors carefully considered. Upon talking to us and booking a free site survey we will be able to advise you on what size and style of extension would be most suitable for your particular house, garden and requirements.


While it’s fresh in your mind why not download a free brochure

Click Here

granny annexe brochure




Recently Completed

Order a free brochure to be posted to your home

The brand NEW Granny Annexe brochure is full of recent customer photos & prices plus full details of all the options for kitchens, bathrooms and more... Please click here to order a free brochure

Ask us all your questions

Contact the Granny Annexe Helpdesk with all your questions. We're open from 9am to 5pm Monday - Friday. Call us free on 0800 334 5774 or Email us.