Exterior rendering styles fall into two layers. The first is the material on the wall: lime, cement, monocouche, acrylic or silicone. The second is the finish: smooth, scraped, roughcast, pebbledash, Tyrolean or ashlar. The same phrase is also used for CGI, where it means how a building is visualised. This guide covers both, because developers and architects have to specify the wall and then show it convincingly before anything is built.

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Visual Trick creates exterior CGI and verified photomontage to help present render finishes clearly before a project is built.

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TL;DR

  • Render has two choices: the material (lime, cement, monocouche, acrylic, silicone) and the finish (texture). Most finishes can be had in most materials.
  • Old, traditionally built properties generally need breathable lime render. Strong cement renders can trap moisture and cause decay.
  • Silicone render typically costs more per square metre than sand and cement, but it is the more common premium choice for new work.
  • In CGI, the finish only reads correctly when texture scale, colour and lighting are set deliberately. A wrong finish on a planning image invites questions.
  • We produce exterior CGI and verified photomontage in-house, so finish choices can be tested visually before anything is built.

Table of Contents

Two meanings of exterior rendering

On a building site, “rendering” is a coat of sand-based mix applied to an external wall. In our industry, it is a computer-generated image of a building’s exterior. Search results for this topic lean heavily towards the first meaning, and rightly so: the finish you choose is what a visualiser then has to reproduce.

If you are a developer, architect or planning consultant, you will meet both. The render specification goes into the drawings, and the CGI shows the planning officer, the investor or the buyer what that specification will look like at 4pm on a grey October afternoon.

Material and finish are different decisions

The most useful distinction in this subject is the one most guides blur. The material is what the render is made of. It sets how breathable the wall is, how long the coating lasts and what it costs. The finish is the surface texture applied to it. Weber’s guide to façade textures lists the common finishes: scraped, fine scraped, roughcast, dry dash or pebbledash, Tyrolean, travertine, textured, smooth and ashlar or lined. The finish changes how the surface looks and how cracks and dirt show, but it does not change what the render is.

That is why a brief should always state both. “Cream render” tells a visualiser very little. “Silicone render, fine scraped finish, off-white” tells them exactly what to build in the model.

Render finishes compared

The table sets out the finishes you will meet most often in the UK and what each tends to look like on an elevation.

Finish Appearance What it means for visualisation
Smooth Flat, uniform, contemporary Shows every shadow line and joint, so the model must be precise
Fine scraped Subtle grain, softly matt Needs a fine texture map that holds up in close views
Scraped Pronounced vertical or random grooves Texture catches raking light and changes with sun angle
Roughcast Coarse, gravelly, heavy texture Large surface relief, visible even in wide elevations
Pebbledash (dry dash) Loose aggregate pressed onto the wall Speckled colour variation across the surface
Tyrolean Sprayed, stippled, uneven Reads as a soft, irregular peppering
Travertine Pitted, stone-like Works well for a premium, natural-stone impression
Ashlar or lined Smooth render scored into blocks Joint pattern must align with openings and corners

Two practical rules apply, both noted by Bright Home UK. The smoother the finish, the better the wall underneath needs to be. And texture hides dirt and hairline cracks but also holds algae, which is why a self-cleaning material matters more on a heavily textured wall.

Roughcast and pebbledash are not the same thing

They are often confused, and the confusion shows up in specifications. The SPAB explains that roughcast has a coarse finishing coat with gravel premixed before it is thrown onto the wall, while pebbledash has the aggregate applied separately onto wet plaster. Roughcast is a lime-based render. South Gloucestershire Council’s guidance on lime render on historic buildings says it should never be replaced by pebbledash, which is a modern, cement-based form of render.

Roughcast and pebbledash application compared

For an image, this matters. Roughcast on a heritage building and pebbledash on a 1930s semi have different colour depth and different shadow behaviour, and a reviewer who knows the area will notice if they are swapped.

The main render materials

Homebuilding magazine’s guide to types of house render names cement, polymer, acrylic, silicone, monocouche and lime renders. In practice, the choice for most projects comes down to a few of them.

  • Lime render. Best for old houses where breathability is essential. It is the traditional choice and the one conservation officers expect on historic fabric.
  • Sand and cement. The traditional budget option, usually painted afterwards to give colour.
  • Monocouche. A single-coat, pigmented system described as hard-wearing, low-maintenance and weather-resistant.
  • Acrylic. A polymer-based, flexible, pre-coloured system.
  • Silicone. A polymer-based system with water-shedding properties, widely used where a self-cleaning, low-maintenance wall is wanted.

Because finishes come in most materials, you can specify a scraped silicone or a scraped lime, and the CGI will show a similar texture with a different colour behaviour and sheen. The material affects how the surface takes light: lime tends to look chalky and softly matt, while pigmented polymer systems can look crisper and more even.

Older and traditionally built properties

This is where a wrong style choice has real consequences. The SPAB’s technical note on why old buildings need to breathe says old buildings rely on breathability rather than barrier systems to manage moisture, and that modern materials such as Portland cement are often incompatible with them. Its advice is to check the construction first and use permeable materials such as lime render.

The New Forest National Park Authority’s guidance on plasters and renders makes the same point for buildings constructed before the mid-19th century: they generally depend on moisture evaporating, and cement render can trap it and damage the building.

Exposure matters too. The SPAB notes that roughcast suits exposed districts, because its heavy texture creates a larger surface area that helps moisture evaporate. If you are working on a restoration, understanding what is already on the wall comes first, and historic mortar analysis shows how the existing material is identified before anything is repaired or matched.

For planning, the practical consequence is simple. A scheme that touches a listed building or sits in a conservation area needs a render specification that makes sense for the building, and a visual that shows exactly that specification.

Older and traditionally built properties

What render styles cost in the UK

Cost figures vary by region, access and condition, so treat them as ranges for budgeting rather than quotes.

  • Silicone render is quoted at £45 to £55 per m² for supply only, or £9,000 to £11,000 to render a 200 m² semi-detached house, according to MyJobQuote’s 2026 guide.
  • One contractor’s indicative price guide puts traditional sand and cement at £40 to £70 per m², silicone at £60 to £100 per m² and K Rend at £60 to £110 per m², with a full render of an average semi-detached at £5,000 to £12,000.

Is coloured render more expensive? Usually the colour itself is not the issue; the system is. Another contractor’s colour rendering guide says standard colours are the most affordable, bespoke colours increase material cost, and special textures or custom shades can require extra materials or longer application. The same guide gives £80 to £120 per m² for coloured rendering, materials and labour together.

The finish matters less to price than the material, but a distinctive texture or bespoke shade is exactly the kind of choice worth seeing in an image before it is priced and ordered.

Our perspective

We see render specifications go wrong in images long before they go wrong on site. The usual cause is a brief that names a colour and nothing else. A render is a material, a finish, a colour and a way of meeting the window reveal, the eaves and the ground. Leave any of those out and the image becomes a guess.

Our approach is to ask the project’s purpose first. A planning image needs the finish to match the specification in the application, because it is read against the drawings. A marketing image can lean on mood and light, but it should still be recognisably the same wall. Every image is produced in-house by one experienced operator, so the person who reads your render schedule is the person who builds the scene. That means direct communication, predictable deadlines and no details lost in a hand-off.

If you are choosing between two finishes, we would rather show you both on the same elevation under the same light than argue about them from a sample board.

Paride

Showing render finishes accurately in CGI

The second meaning of exterior rendering styles is visual. Different projects call for different treatments, and we explore the approval side in our piece on rendering styles that win client design approval. Where the finish is concerned, a few points decide whether an image is believable.

  1. Texture scale. A roughcast texture drawn at the wrong scale looks like cardboard. The grain must be sized to real-world dimensions so it reads correctly from both the front door and the street.
  2. Colour under daylight. Render colour shifts with the weather and time of day. Pale colours need careful exposure so they do not burn out, and that is a lighting question. Our note on exterior lighting settings for CGI covers how we approach it.
  3. Weathering. New render looks clean. If the image has to show a building as it will look in a few years, or sit beside existing weathered neighbours, the surface can be adjusted to suit.
  4. Details at junctions. Render stops, expansion joints, window reveals and cills are where the wall looks real or fake.
  5. Context. The wall has to sit alongside brick, cladding, stone, roofing and planting that genuinely match the site.

For planning submissions, the image has to be accurate rather than merely attractive. Our planning visuals include CGI photomontage, aerial CGI photomontage and verified views, and our guide on planning-grade visual documents explains what that standard involves.

Choosing a style by project type

  • New-build housing: a single consistent finish with a considered colour palette usually photographs better than several competing textures.
  • Extensions and refurbishments: match the existing finish first, then show any contrast deliberately.
  • Heritage and conservation sites: use lime-based looks and softer, slightly irregular textures, and make the image match the specification.
  • Care and healthcare buildings: calm, low-contrast finishes with warm tones present a domestic, reassuring character.
  • Contemporary schemes: smooth or fine scraped finishes with crisp junctions, which need a precise model.

Visualise your render before you build it

If you are specifying exterior finishes for a development, extension or planning application, we can show them on your building before anything is ordered. Our exterior CGI service covers photorealistic elevations and street views, and our wider architectural visualisation and rendering services cover planning, marketing and design development. Send us your drawings and render schedule and we will work from them.

Visual Trick - CGIs, Animations, Digital Twins

For a sense of how visuals fit into a wider design process, our guide to why architects use 3D visualisation is a good next step.

FAQ

What are the different types of external house render?

The main types are lime, sand and cement, monocouche, acrylic and silicone, with polymer systems sitting alongside them. Each is a material, and each can be given a finish such as smooth, scraped, roughcast or pebbledash. Lime suits old buildings, while monocouche and silicone are the common low-maintenance options for newer ones.

Is coloured render more expensive?

Not always. Standard colours are generally the most affordable, and bespoke colours or special textures can add material cost and application time. The type of render system usually has a bigger effect on price than the colour.

What is the difference between render and roughcast?

Render is the general term for a coating applied to an external wall. Roughcast is one specific type: a lime-based render whose coarse finishing coat has gravel mixed in before it is thrown on. Pebbledash is different, because the aggregate is applied separately onto the wet surface.

What is an exterior rendering in CGI?

It is a computer-generated image of a building’s outside, showing materials, finishes, light and surroundings. It is used for planning applications, marketing and design approval. A good one reproduces the specified render finish accurately so the image matches what will be built.

Sources