15 Rear Extension Design Ideas

If you are looking to add space to your home, a rear extension might be the easiest to accommodate from a planning and spatial point of view. Architecture North shares projects to inspire you

If you’re looking to add value as well as extra space to your home, then a rear extension may be the project for you.

If you are carrying out your work under Permitted Development, you will be expected to build in the same material as the existing dwelling. This must be done carefully, perhaps requiring you to source reclaimed materials to get a good match, or tint the bricks for a seamless look.

Alternatively, you could design an addition in a contrasting style. This makes a statement and can be easier to achieve success with than trying to match old and new.

Here, we take a look at some of the finest examples of rear extensions in recent times.

1. A Striking Clad Extension


This grey rendered blockwork ground floor extension supports a timber frame bedroom ‘box’ above.

  • Build cost: £175,000

  • Location: Hampshire

2. A Sensitive Extension


A contemporary-style addition clad in western red cedar contrasts with this original Grade II-listed cottage.

  • Build cost: £175,000

  • Location: Hampshire

Do I Need Planning Permission for a Rear Extension?

If your home is not in a conservation area or restricted by Listed Building consent, you may find your rear extension falls under Permitted Development.

This means that you can extend up to 8m from the original rear wall of your property on a detached home, or up to 6m on a semi detached or terraced home. In either case, your extension must not be higher than 4m. There are further restrictions if your project is to sit within 2m of a boundary (in this case the eaves must not be higher than 3m).

These measurements apply to single-storey extensions only, but some two-storey additions are allowed too.

3. An Extended and Renovated Cottage


A new glazed space to a traditional whitehouse croft, provides a kitchen and utility room filled with natural light.

  • Build cost: undisclosed

  • Location: Isle of Skye

4. A Modernist Addition

A cantilevered timber-clad roof appears to float on clerestory windows set above a white rendered wall on one side, and sliding doors on the other.

  • Build cost: undisclosed

  • Location: Denbighshire

Thinking about a single storey extension? Here’s what you need to consider

5. A Listed Stone Cottage Extension


The sympathetic oak frame addition, with reclaimed triple Roman clay tile roof, offers a family sunroom.

  • Build cost: undisclosed

  • Location: Bath

6. An Extended Farmhouse


Two new structures, clad in timber and Cor-ten steel, are linked to this old farm building with a glazed corridor.

  • Build cost: £355,800

  • Location: Inverness-shire

7. An Extended 1950s Home


This large rear addition incorporates a spacious kitchen diner and separate open plan living room, which open on to a patio.

  • Build cost: undisclosed

  • Location: Cardiff

8. A Glazed Kitchen Addition


This single-storey kitchen extension opens onto the garden with powder-coated bifold doors from Origin.

  • Build cost: £120,000

  • Location: West Midlands

9. A Zinc-Clad Rear Extension

This rear single-storey addition to a London flat in a conservation area has been clad in a pre-coloured dark zinc.

  • Build cost: £240,000

  • Location: North-west London

10. A Frameless Glass Extension


Using contemporary frameless glass, a new bright open plan kitchen/dining/living space has created, which opens on to the rear garden without impacting on the traditional brick shell of the building.

  • Build cost: £400,000

  • Location: Hampshire

11. A Dramatic Remodel


This 1930s dormer bungalow has been transformed into a stunning chalet-style home thanks to a series of rear and side additions.

  • Build cost: £150,000

  • Location: Worcestershire

If you’re thinking about adding a single storey extension, make sure you read this first

12. A 1950s Home Extended


This 1950s home has been opened up thanks to a rear extension which houses a new kitchen diner that connects with the garden through bifold doors. The addition has been clad in white render to contrast against the existing brick building.

  • Build cost: £95,000

  • Location: Bedfordshire

13. A Budget Addition


Thanks to a new kitchen extension, this formerly cramped 1930s semi-detached home now offers the family with much-needed additional space. The crisp white render and modern glazed openings create a clear distinction between old and new.

  • Build cost: £40,000

  • Location: Nottingham

14. A Cantilevered Wing


As part of the conversion of the stone barn on site, a dramatic cantilevered timber-clad bedroom wing extension has also been added to create the space the homeowners need and create a clear separation between living and sleeping quarters.

  • Build cost: £350,000

  • Location: Northern Ireland

15. An Extended Barn Conversion


Built of and clad in CLT (cross-laminated timber) with frameless glazed openings, this lateral extension spans the rear of the site, consequently reorientating the outlook of the existing Grade II-listed barn, to make the most of the garden views.

  • Build cost: £250,000

  • Location: Hampshire