Render or cladding: Which building materials can I use for my extension?

While it’s typically for the interior space you start an extension project, it’s important to consider the exterior design of any extension. Particularly where it faces into your garden or any other outside area it is likely to provide visual appeal. In this guide. we’ll look at cladding and render extensions, and other popular materials used in architecture that could be perfect for your next extension project.

Material 1 - Brick

Brickwork is a common option and this is for good reason. It is loadbearing, affordable and has excellent aesthetic properties.

Material Pros:

  • Easily accessible and low cost

  • Easy to provide additional flare and aesthetics with different bricks and patterns.

  • Low amount of maintenance.

Material Cons:

  • Wet trades can be messy on-site, be sure to coordinate this early in the construction process.

  • Brickwork does require repointing depending on the quality of the mortar and brick.

Material 2 - Render

Another common material, silicone based renders are often the quickest and most affordable compared to almost any other material on the market.


  • Often the most affordable exterior finish.

  • Normally fast application on-site.


  • The most difficult material to make aesthetically pleasing in large portions. Planting could be explored here.

  • White and other bright colours require cleaning or regular painting.

  • Can be fiddly and more expensive on timber frame extensions.

Material 3 - Timber Cladding

Timber cladding can be applied in a variety of ways with different woods providing unique aesthetic qualities.


  • Simple application and removes wet trade application for the exterior.

  • Some of the best aesthetic qualities available with a variety of options.


  • Often more expensive

  • Longer to install

  • Requires the correct treatment and understanding of how it effects the wood.

  • Sunlight will weather timber differently over time which can cause inconsistent finishes across multiple faces.

Credit @Al-Jawad Pike

Credit: Al-Jawad Pike on @gtsantilas

Material 4 - Alternative Blockwork

Most would not consider blockwork an acceptable exterior material for a building, however many high quality projects show how different block and mortar colours and provide a unique and impressive finish.


  • Very affordable.

  • Quickest to install.


  • Requires design understanding to work aesthetically.

  • Requires correct finishes and maintenance to remain visually high quality.

  • Some bespoke colours and finishes can make this option more expensive.

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Credit @Kirkwood McCarthy

Credit: Kirkwood McCarthy on @archinectuk

Material 5 - Metal Seam

A popular material for contemporary projects, metal seams provide an even rhythm material which compliments most projects.


  • A safe aesthetic choice for any design.

  • Most meal roofs will last for a long time.


  • Often expensive, installers are rare and expensive.

  • Requires correct construction design.

  • Can be noisy in the rain!

Material 6 - Corten

Another common material used in contemporary design, this material consists of steel that has been rusted to provide an industrial red treatment on the outside.


  • A safe design choice for aesthetics.

  • Will last a long time.


  • Also expensive, although installation is often easier than metal seam.

  • It has been used to a lot the last decade and now feels quite overdone in the industry.

Material 7 - Cork

Cork is a material which has been rising in popularity in the last few years. Its unique aesthetic and thermal qualities make for many award winning projects.


  • Safe material for aesthetic design.

  • Can often double as external insulation.

  • Light and easy to install.


  • Still an expensive material that is difficult to source.

  • It is yet to be seen how cork lasts on buildings long term.

Credit @S&M Office

Credit: @officesandm

Material 8 - Shingles

While common on roofs, tiles can also be used on walls as seen on many contemporary and arts & crafts buildings.


  • Many varieties and materials available.

  • Design flare is possible through uncommon types of shingle.


  • Requires the correct construction detailing.

  • Can be expensive depending on the shingles used.

  • Some shingles can be difficult to maintain long term.

Render or Cladding? It’s all about picking the materials that work for your locale and needs…

Some projects will have particular material that will work particularly well for their location and site. Make sure to always establish a material palette and design before jumping into installing your exterior material.

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