Skip to main content

8 Side Extension Design Ideas

Dramatic oak-frame side extension to bungalow
(Image credit: English Oak Buildings)

Once you have assessed whether it is worth extending your home, thoughts often turn to the type and style of extension that would work for you. Whether you want something contrasting or sympathetic, single or two-storey, extending out to the rear or the side, the available options are incredibly varied.

Here we take a look at eight great examples of extending out to the side of the original property.

Do I Need Planning Permission for a Side Extension?

In many cases, you will be able to add a side extension under your Permitted Development Rights, as long as the proposed project meets certain criteria (although this may not be the case in Conservation Areas or AONB):

  • the extension cannot sit forward of the principal elevation
  • it should be built using similar materials
  • if it is within 2m of a boundary, the eaves cannot be higher than 3m and not taller than 4m otherwise
  • the width of the side extension must not be greater than half the width of the original dwelling

(MORE: Want to extend out the back of your property? Check out these design ideas)

If you are looking to extend outside of this criteria, then you will need approval from the local planning department.

If in doubt, always check with your local authority before starting any building work, You can also see the for a full list of caveats.

1. Contemporary Timber Extension

Granite side extension to farmhouse

(Image credit: Nigel Rigden)

A larch and stainless steel addition gives a spacious new wing to a traditional granite farmhouse.

  • Build cost: £466,500
  • Location: Aberdeenshire

2. Charming Oak Frame Addition

Traditional style extension to side of bungalow

(Image credit: Simon Maxwell)

An oak-framed wing by Border Oak has been added to this 1940s bungalow to create annexe accommodation and add traditional charm.

  • Build cost: £200,000
  • Location: Kent

3. Glazed Extensions to Old Cottage

Glazed side extension to cottage

(Image credit: Simon Denison)

An old cottage and two derelict barns have been linked by a glazed structure, unifying the structures to create a family home.

  • Build cost: undisclosed
  • Location: Powys

4. Oak Addition Revamps Tired Bungalow

Dramatic oak-frame side extension to bungalow

(Image credit: English Oak Buildings)

A small bungalow has been transformed by a dramatic oak frame side extension, with floor-to-ceiling glazing to maximise woodland views.

  • Build cost: undisclosed
  • Location: Cornwall

5. Semi-Derelict Barn Transformed

Extension to lochside house

(Image credit: Nigel Rigden)

A converted lochside barn has been extended to house utilities. It was clad in larch to compliment the original stonework.

  • Build cost: £200,000
  • Location: Highlands

6. Contemporary Extension to Thatched Cottage

Glazed side extension to cottage

(Image credit: Luke Foreman)

A contemporary extension with a partially glazed roof doubles the size of the original 17th-century cottage.

  • Build cost: £210,000
  • Location: Oxfordshire

7. Adding Space to Art Deco Home

Curved side extension

(Image credit: Simon Denison)

This single-storey curved addition has been roofed in stainless steel to provide a writing room, utility and kitchen/dining room.

  • Build cost: £392,000
  • Location: Bath

8. Sympathetic Extension to Georgian Farmhouse

Side extension to farmhouse

(Image credit: Dave Burton)

The homeowners of this period farmhouse have added space with a sympathetic side extension. It was a challenge to source reclaimed bricks to match the original house, but was an essential step in ensuring that the extension looked the part when complete.

  • Build cost: £60,000
  • Location: North Yorkshire