Comparisons
Precast wall vs wall built on site: which to choose?
The material is the same: concrete. What changes is where it is made. In a traditional wall, blocks or formwork and concrete pouring are carried out on site, with a footing, curing times and finishing. With precast, the pieces arrive ready-made from the factory and on site you only drill the holes, set the posts and slot in the panels. The practical difference lies in the lead time, in the dependence on the weather and in who guarantees the quality of the concrete.
What each solution is
Wall built on site
Foundation footing, concrete blocks laid with mortar or formwork with reinforced concrete cast in situ, followed by rendering and painting. Wet works from start to finish, with setting times between stages and sensitive to rain and cold.
It is the most flexible solution in terms of geometry: it follows curves, angles and varying heights without depending on a module.
Precast concrete wall
Panels and posts moulded in the factory by vibro-compaction, cured under controlled conditions and checked before they leave. C35/45 concrete. On site: holes of 300 × 300 × 800 mm, posts plumbed and concreted, panels slotted in dry.
It is the most predictable solution: what arrives at the plot already has its geometry and strength decided.
Free quote, with no obligation. Tell us the municipality, the length and the height — we reply with a figure.
Criterion-by-criterion comparison
This is the comparison in which the precast option no wins on the starting price. It wins on other things, and each line says which. All the price references quoted come from a professional price generator or from indicative market values, with the source at the end.
| Criterion | Made on site | Precast concrete wall | Criterion conclusion |
|---|---|---|---|
| Price, direct reference | Concrete wall cast in situ for plot fencing, height 1 m, 15 cm thick, with reusable metal formwork: 80.04 €/m, material and labour | Material from 25 €/m² plus installation 59–79 €/linear m, excluding VAT. Market reference for precast panels: 120–180 €/l.m. | Made on siteThis is the fairest comparison there is, because it is the same product — a concrete wall for fencing — and the one built on site starts out cheaper. Note the height: 1 m. |
| Price, block masonry | 15 cm concrete block masonry wall: 23.03 €/m², still without render or paint. Rendered and painted, the market indicates from 80 €/l.m. | Material from 25 €/m², with the texture already as the final finish | DependsPer m² of material the two start from similar prices. The difference shows up later: the block still needs rendering and painting, the panel does not. |
| Lead time | Footing, reinforcement, masonry, render, paint — stages chained together over weeks | 20–30 m per day in normal conditions | ConcreteThis is the advantage that pays for the price difference when the job is on a schedule. |
| Weather dependency | High: rain and cold stop concrete pouring and rendering | Low: the only concreting is the filling of the holes | ConcreteIn the Portuguese winter this line is worth more than it seems. |
| Foundation | Usually a continuous reinforced footing along the whole alignment | No strip footing: one 300 × 300 × 800 mm hole per post, 800 mm buried | ConcreteLess excavation, less concrete and less earthmoving. |
| Concrete class | The reference cast-in-situ boundary wall uses concrete C25/30 with AR42 mesh | Concrete panels C35/45, reinforced with Ø3 mm welded steel mesh + fibreglass | ConcreteTwo classes above the usual reference. It is a difference in specification, not in marketing. |
| Concrete quality control | Made on site: it varies with the mix, the dosage and the workmanship on that particular day | Made in a factory: vibro-compaction, controlled curing, constant geometry | ConcreteThe strength no longer depends on the day and on the team that was on site. |
| Thickness | The reference for concrete cast on site has 15 cm thick along the whole panel run | Panel of 30 mm, with the 120 mm post only every 2 metres | ConcreteLess material, less weight and more usable area on the plot for the same function. |
| Maintenance cost over 10 years | Stated in the reference for the wall concreted on site: 4.00 € per metre | No compulsory cost; painting is optional | DependsNeither solution needs heavy maintenance. It is the render that ages, not the concrete. |
| Freedom of geometry | Curves, free angles, heights varying point by point | Fixed 2 m module; heights in 500 and 300 mm courses | Made on siteOn an irregular layout, a wall built on site solves what the modular one cannot. |
| Finish | Render and paint, to be redone periodically | Texture moulded into the piece itself; paint optional | ConcreteA finish that is part of the piece does not flake and does not require repainting. |
| Cracking | Risk of shrinkage and settlement cracks along the run | Independent panels; movement is absorbed at the joints | ConcreteIt is the classic weakness of a continuous run cast in situ. |
| Repair | Chipping, redoing, repainting — the patch shows | The affected panel comes out and another goes in | ConcreteRepairing a rendered section invisibly is practically impossible. |
| Structural function | It can be sized to retain earth, with a design | Not suitable as a retaining wall: designed for wind loads, not for earth pressure | Made on siteIf the wall has to hold back a slope, a precast wall is out of the question. |
| Waste and disruption on site | Sand, mortar, render debris, a site compound for weeks | Pallets and little more | ConcreteIt matters when the work is in an established garden or an occupied house. |
Delivery is not included in these prices. Delivery of the material to the site is quoted separately, by municipality and volume.
What the price per metre does not show
The schedule. Published figures for a rendered and painted block wall start at 80 € per linear metre, below the market reference for precast panels, which is 120 to 180 €/linear m. What that figure does not include is time: sequential stages, curing times between them and stoppages for rain. On a wall that has to be ready for a date, that difference stops being abstract.
Where quality is decided. In a wall cast in place on site, the strength depends on the mix and the workmanship on that particular day, on that particular plot. With a precast system, that is decided before the piece leaves the factory.
What happens ten years from now. A rendered wall face needs repainting and shows the patches when it is repaired. A modular system replaces the affected piece and stays the same.
Frequently asked questions
Is precast weaker than a wall cast in situ?
They are designed for different purposes. The panels are C35/45 reinforced concrete with a Ø3 mm welded steel mesh + fibreglass and withstand wind load and impact. What they do not do is retain earth — for ground pressure a calculated structure is needed, whatever the system.
Do I need a foundation footing?
There is no strip footing. Each post is concreted into its own 300 × 300 × 800 mm hole, with 800 mm buried; the minimum is 700 mm. It is that embedment that provides the wind resistance of the whole run.
And if the plot is on a slope?
The wall follows the level in panel steps. Intermediate heights are resolved by combining 500 mm courses with 300 mm courses.
Can I render and paint the precast wall?
Painting yes, and it is advisable: a paint system with a primer seals the surface and increases resistance to UV rays. Rendering makes no sense — it would lose the texture, which is precisely the finish you are paying for.
My plot has curves. Will it work?
A curved line requires faceting into straight 2 m segments. If the curve is gentle it can be resolved; if it is tight, a wall built on site follows it better.
Free quote, with no obligation. Tell us the municipality, the length and the height — we reply with a figure.
Completion
Precast concrete wall or built on site: how to decide
Against traditional in-situ concreting, precast wins on lead time, predictability, foundation, finish, cracking and repair; it loses on starting price, freedom of geometry and structural capacity. Translated: if the line is regular and there is a schedule, precast; if the wall has to retain earth or follow a free geometry, the wall built on site — and there we do not even compete.
Choose the concrete wall if…
- there is a set date, or the wall follows the pace of another job;
- the perimeter is long and you want the same look from start to finish;
- you want the finish sorted with no render or compulsory painting;
- you do not want wet works or rubble on the plot;
- want to be able to replace a piece in the future.
Choose cast on site if…
- the wall has to retain earth — there you need a calculated structure;
- the geometry is irregular: tight curves, angles outside the 2 m module;
- the wall continues an existing structure, with no joint;
- the lorry cannot reach the alignment and unloading is impossible;
- the quote is the only criterion and the lead time does not matter.
Where they are equal
- material: it is concrete in both cases;
- durability: both last for decades when properly built.
How much it costs in your case
Tell us the municipality, the length and the height. We reply with a price and the lead time for the material — and if the right solution for you is the other one, we say so.
Sources
The third-party figures quoted on this page are not our own estimates. The references they came from are given here so that you can check them.
- Concrete wall cast on site to fence a plot, 80.04 €/m at 1 m high and 15 cm thick, C25/30 concrete, ten-year maintenance 4.00 € geradordeprecos.info
- Concrete block masonry wall, 15 cm, 23.03 €/m² geradordeprecos.info
- Block wall from 80 €/lin.m, reinforced concrete wall from 200 €/lin.m and precast panel wall 120–180 €/lin.m — indicative market figures naveganteconstrucoes.pt