Key Takeaways
- Installed costs run from £20 to £50 per m² to repoint brick, £30 to £110 for render at London prices and £60 to £160 for cladding (MyJobQuote, 2026).
- Maintenance is the real cost: cement render lasts 7 to 15 years, silicone render 25 to 30, and brick pointing 40 to 60.
- Re-rendering a whole elevation triggers Part L, which asks for a wall U-value of 0.30 W/m²K unless you fail the feasibility or 15-year payback test.
- On a house under 11m, cladding faces no reaction-to-fire provision if the wall is 1m or more from the boundary, and needs class B-s3,d2 or better if it is closer.
- On solid Victorian brick, a hard cement render is the classic route to trapped damp.
The exterior finish decides how a home looks, how much upkeep it needs and, on a solid-walled London terrace, whether the walls stay dry. Cost per square metre is the least useful way to compare them, so this guide sets out the maintenance cycles and the two regulations that catch people out.
The three finishes compared
Brick is the cheapest to keep and the most expensive to build new; render is cheapest to apply and the shortest-lived; cladding spans both depending on material.
| Finish | Installed per m² | Lifespan | Maintenance |
|---|---|---|---|
| Repointing existing brick | £20 to £50 | 40 to 60 years | Almost none |
| Cement and sand render | £30 to £55 | 7 to 15 years | Repaint every 5 to 10 years |
| Monocouche render | £45 to £90 | 20 to 30 years | Low, but colour-matched repairs are difficult |
| Silicone thin-coat render | £60 to £110 | 25 to 30 years | Very low, sheds dirt |
| Lime render | £55 to £100 | 20 to 30 years | Annual clean, patch repairs |
| Timber cladding | £60 to £100 | 20 to 40 years | Re-treat every 2 to 5 years |
| Fibre cement cladding | £80 to £130 | 30 to 50 years | Minimal |
| Aluminium cladding | £100 to £160 | 40 years plus | Minimal |
| External wall insulation, render finish | £90 to £230 | as the render | as the render |
Add scaffolding at roughly £800 to £1,500 on a two-storey London house, and around £4,500 to strip existing render before you start again. Whole-property external wall insulation runs from about £8,000 on a terrace to £19,000 on a larger detached house.
Brick
On a period London home, keep it. Brick is the only one of the three where the maintenance cycle is measured in decades rather than years: good repointing lasts 40 to 60 years, and repointing a whole semi costs roughly £1,900 to £4,750. Use a lime-based mortar on older bricks, not a hard cement mix, because cement traps moisture and spalls the brick faces. Covering a sound period facade is usually a loss of both character and value.
Render
Render earns its place on tired, mismatched or previously rendered walls, and the system matters more than the price. Modern silicone thin-coat systems are the low-maintenance choice on sound substrates at £60 to £110 per m² in London, lasting 25 to 30 years and shedding dirt. Cement and sand render is cheaper at £30 to £55 but cracks and needs repainting every 5 to 10 years.
On a pre-1919 solid brick wall, breathability decides the outcome. Lime lets the wall dry out; cement and low-breathability thin coats hold moisture in the masonry, which is how you get blown render outside and damp inside. The SPAB position is blunt: cement and similar alternatives can seriously harm historic fabric. Never apply lime over existing cement render either, because you simply trap the moisture behind it. See our rendering cost guide and damp causes and fixes.
Source: MyJobQuote and SPAB, 2025 to 2026.Cladding
Cladding suits extensions, modern elevations and anywhere you want a facade that reads as deliberate rather than patched. Fibre cement at £80 to £130 per m² and aluminium at £100 to £160 are the low-maintenance options, lasting 30 to 50 and 40 plus years. Timber is cheaper at £60 to £100 but needs re-treating with oil or stain every 2 to 5 years, which is a decision about your weekends as much as your budget.
What the fire rules actually say about cladding
Less than the headlines suggest for a normal house, and more than people think for one specific product. The statutory ban in Regulation 7(2), requiring class A2-s1,d0 or A1 materials, applies to "relevant buildings" with a storey at least 18m above ground level. It is not an 11m threshold and it does not catch a two or three storey house. What does catch every building at any height is Regulation 7(1A): relevant metal composite material must not form part of an external wall of any building, so cladding a bungalow in a thin metal composite panel with a combustible core is unlawful regardless of height.
For houses, the working rule is Approved Document B Table 10.1. For residential buildings 11m or less in height, the external surface must be class B-s3,d2 or better where the wall is less than 1000mm from the relevant boundary, and there is no reaction-to-fire provision where it is 1000mm or more away. That one dimension decides whether timber cladding is straightforward or needs a tested classification, and on a London terrace flank wall it very often falls the wrong side. A Building Safety Regulator consultation on Approved Document B also closed on 1 July 2026 proposing a review of the ban's scope, so check the current position before specifying.
Source: Building Regulations 2010 Regulation 7 and Approved Document B Volume 1, 2019 edition with amendments to 2026.The Part L trap when you re-render or re-clad
Re-rendering counts as renovating a thermal element, and most people do not know it. Approved Document L states plainly that "providing a new layer through cladding or rendering the external surface" of a thermal element is a renovation, as is stripping back to the brick and rebuilding. Once more than 50% of that element is renovated, the whole element should be improved to the Part L standard.
The measurement is what makes this bite. For external work, the thermal element is the area of the elevation in which the wall sits, so re-rendering one complete elevation of a semi is the whole of that element, not a fraction of the house. The target is 0.30 W/m²K for a wall upgraded with internal or external insulation, and a solid Victorian wall is always in that category because it has no cavity to fill.
There is a genuine get-out. If achieving 0.30 is not technically or functionally feasible, or would not pay back within 15 years, you upgrade to the lowest U-value that is feasible and does pay back, generally no worse than 0.7 W/m²K. There is also a concession where insulating would reduce the room's floor area by more than 5%. Ignore the common claim that the trigger is 25% of a wall: the 25% figure refers to a major renovation of the whole external envelope, not one elevation. See external wall insulation and building regulations explained.
Source: Approved Document L Volume 1, 2021 edition incorporating 2023 amendments, paragraphs 11.2 to 11.4 and Table 4.3.How to choose
If the brick is sound, repoint it and stop there. It is the cheapest option over 20 years and the only one that keeps a period London facade worth what it is worth. If the wall is already rendered, or is a poor mixed brick, use a silicone thin-coat system on modern substrates and a lime system on pre-1919 solid walls. Paying £55 to £100 per m² for lime on a Victorian terrace is cheaper than a damp problem. Use cladding on extensions and modern elevations, check the 1m boundary rule before choosing timber, and price fibre cement if you want to stop maintaining it.
Whichever route you take, if you are doing a whole elevation, budget for the Part L upgrade rather than discovering it at inspection, and check conservation area rules first: on designated land, cladding or rendering needs planning permission even where it would be permitted development elsewhere, and permitted development does not apply to flats at all. On a wider renovation across London and the surrounding counties, GS Renovation can coordinate a specialist renderer, bricklayer or cladding installer alongside the rest of the job. For advice, contact us or call 07472 424 226.