Civil engineering Vienna what lies underground determines the price.

Civil engineering Vienna: costs 2026

Guide values net, as of 2026. The individual services have their own pages with complete price tables.

Cross-cutting prices that occur in every civil engineering project

We complete driveways, car parks and private roads after the civil engineering work: asphalting with sub-base, drainage and surface course.

If it is not about individual civil engineering works but about a whole route with utilities and carriageway, the way leads via road construction – where it is also explained why from the sewer onwards the calculation is in linear metres instead of square metres.

What civil engineering covers – and why the sequence determines everything

Civil engineering is everything that happens below ground level: excavation, foundations, utilities, drainage, securing the excavation and reinstatement afterwards. For the client it is the most invisible part of the project and at the same time the one where most extra charges arise – because only after the first bucket of the excavator do you know what is actually in the ground.

The condition survey is the point that is most often left out and most bitterly regretted. Anyone digging next to a Gründerzeit building in Vienna is practically always standing next to cracks that were there before. Without documentation before construction starts, this can no longer be told apart – and in practice the burden of proof then lies with the contractor.

The soil decides the price

The same number of cubic metres costs three to five times as much depending on the type of soil. That is why every verifiable offer states which soil class is assumed – and what happens if it turns out differently.

Then there is the water content. A loamy soil is easy to work when dry and practically unusable after three days of rain: it can neither be compacted nor transported away without dirtying the road. That is why we prefer to postpone excavation work in cohesive soil by two days rather than install material that will settle later.

Securing the excavation: slope, shoring or sheet piling

Beyond a certain depth, an excavation no longer stands by itself. How it is secured depends on depth, soil, space and neighbouring buildings – and it is the largest single item as soon as things get tight.

Why this is so important: an unsecured excavation is not just an occupational safety problem, it also pulls the neighbouring ground with it. If the neighbouring building settles, the project ends in court instead of on site. That is why shoring is planned according to the regulations and not estimated from experience; for building pits next to existing buildings, a structural assessment is mandatory.

Water in the excavation

Groundwater and perched water are the most common reason why a civil engineering project becomes more expensive than calculated. Both can be determined in advance – the soil survey states the level at the time of drilling, and it fluctuates with the seasons.

Important here: lowering groundwater requires a permit under water law in Vienna and needs lead time. Anyone who only finds this out when the pit is full of water loses weeks. That is why the question of the groundwater level belongs in every first meeting, even if the project seems small – for basements and deep sewers it determines the entire process.

Backfilling and compaction: the invisible difference in quality

After the pipes are laid, the trench is backfilled. Nobody sees what happens here – and that is exactly why this is where most corners are cut. The consequences show one to three years later as a groove in the asphalt, a sinking paved area or a crack in the screed above the backfilled excavation.

Connections: who may do what

For you, this means: we are your contact for everything that happens in the ground and coordinate the operators' appointments. The actual network connections are made by the companies responsible – this is not a division of labour for convenience, but a requirement. What we can promise is that the trench is open when the operator comes, and that it is closed and reinstated again when everyone is finished.

Typical civil engineering projects and what they cost

What accessibility makes up

That is why the first question for every civil engineering enquiry is not "how many cubic metres", but "how does the machine get there and where does the material go". In Viennese courtyards this determines the price more than the excavation volume itself.

Reinstatement: the part the customer sees

After backfilling, the surface has to look the way it did before – or better. This is not an incidental service but a cost block of its own, often missing in offers.

An offer that calculates the trench and leaves reinstatement open is not cheaper – it is incomplete. For a paved area above a 30-metre trench, 5,000 to 10,000 euros can quickly be missing, which will later come as an extra charge.

Drainage: when it is needed

Foundations: what the building stands on

The foundation transfers all loads of the building into the ground. Which type is right is not decided by price, but by the subsoil – and this decision is the only one in the whole project that can practically not be corrected later.

One point that regularly comes up with old buildings: in Gründerzeit buildings, existing foundations often reach only a few centimetres below the basement floor and consist of rubble stone or rammed concrete. Anyone who digs deeper next to them removes their lateral support. This is the main reason why basement deepening and building pits next to old buildings need a structural assessment – see foundation reinforcement.

How a civil engineering project runs

The sequence sounds obvious and is nevertheless often broken – usually because a trade wants to finish earlier. The result is regularly the same: the ground is opened a second time. That is why we stick to the sequence, even if it looks like waiting time in between.

Why civil engineering from a single source is cheaper

• One trench instead of three. Electricity, water, sewer and drainage often lie in the same route. Dig once, lay everything, backfill once.
• One site setup. Excavator, shoring and dewatering come once, not three times.
• One reinstatement. Paving and asphalt are broken up once and closed once.
• One survey. All utilities in one as-built plan – the basis for finding them again in twenty years.

Winter, weather and construction time in civil engineering

Unlike building construction, civil engineering is basically possible in winter, but more expensive and slower. What matters is not the temperature as such, but whether compaction is possible – frozen or waterlogged material cannot be installed, and anyone who does so anyway creates exactly the settlements that nobody can later attribute. We prefer to postpone such work rather than carry it out under the wrong conditions, and we say so beforehand rather than afterwards.

Neighbours, residents and condition surveys

In Vienna, digging almost never happens in an open field. Next to the excavation there is a house, above it a driveway, beside it a garden. What this means:

• Condition survey before construction starts. Photos and crack record of the adjoining buildings, €900 to €3,500. Without it, it is impossible to clarify later which cracks were there before.
• Keeping an eye on vibrations. Pile driving, chiselling and heavy equipment are transmitted through the ground. With sensitive existing buildings, low-vibration methods are used.
• Keeping access open. Residents, ambulances and refuse collection must get through – this belongs in the planning, not in improvisation.
• Dirt on the road. With cohesive soil, trucks carry material onto the road; cleaning is mandatory and is planned in.
• Observing noise hours. Advance notice and fixed working hours prevent most complaints.

Here, too, the most effective measure is also the cheapest: a notice two weeks in advance with period, process and contact person. Residents who are informed report problems to the site management instead of the authorities.

What a verifiable civil engineering offer contains

• The soil class assumed, together with a unit price for deviating classes.
• Excavation quantities in cubic metres, separated into reuse and removal.
• Disposal by tonnes with details of the quality, plus an item for contaminated material.
• Trench metres with depth and width instead of "trench, lump sum".
• Shoring as a separate item, stating from which depth it is included.
• Dewatering, at least as a contingency item.
• Backfilling and compaction stating the material and the proof.
• Reinstatement of the surface by type and area.

If shoring, dewatering and reinstatement are missing, the offer looks 20 to 40 percent cheaper than the project will cost in the end. This is not ill will, but the usual consequence of these items only becoming visible after excavation – which is why they are in our offers from the start with unit prices.

What you get in the end

• Survey of the new utilities with position and depth – a prerequisite for any later excavation.
• Compaction certificates for trenches and excavation bottom.
• Leak test for sewer pipes, pressure test for water pipes.
• Photo documentation of bottom, bedding, pipe position and backfill.
• Disposal certificates for material removed.
• Acceptance report to ÖNORM B 2110 with deadlines and retentions.

Three questions that determine the price more than the quantity

Anyone comparing two civil engineering offers should not look at the total but at the answers to these three questions. They explain almost every difference.

All three can be clarified before the offer – the first during the site visit, the second via surveys and trial trenches, the third by looking at the affected area. That is exactly what we do before we name a price. An offer without this clarification is not a calculation but an estimate with a built-in extra charge.

For the same reason, we do not give a price per square metre or cubic metre for a specific project over the phone. The range would be so wide that it would help nobody: the same excavation costs a third in open ground of what it costs in a courtyard with a two-metre passageway.

After a thirty-minute site visit, on the other hand, it is clear which machine fits in, where the material goes and what has to be reinstated – and with that the price is clear too. The site visit itself is free, throughout Vienna and the surrounding area, within five working days.

The most common mistakes in civil engineering

• Dug without utility detection. A damaged gas pipe is not only expensive but dangerous.
• Quoted without soil analysis. Contaminated spoil costs four to eight times as much at the landfill.
• Shoring skipped. Mandatory from 1.25 m depth – not negotiable.
• Not backfilled in layers. The trench sinks after the first winter, paving and asphalt above crack.
• Utilities not surveyed. In twenty years nobody will know where they are.

Excavation: where to put the material

A detached house produces 250 to 400 cubic metres of spoil, that is 400 to 700 tonnes. What happens to it is a cost block of its own – and the only one where planning can really save money.

The biggest lever lies in the first row: if the spoil is reused on the plot – for landscaping, backfilling or a noise barrier – removal and landfill fees for this volume disappear completely. This requires that the material is suitable and that the level planning provides for it. That is why the question belongs in the planning and not on site when the truck is already waiting.

Who may do what in civil engineering

This division is stated in every offer. For you, nothing changes regarding your contact: coordination of appointments, the condition of the site and reinstatement remain with us, even if five other companies are standing in the trench in between.

Distinction: which page fits

This page bundles what all of them have in common: investigation, soil class, securing, water, compaction and reinstatement. Anyone who needs exactly one of these services gets there faster on the respective page; anyone combining several saves the interfaces with a joint award.

Why civil engineering is the part where projects are decided

In building construction you see every mistake: a crooked wall, a bad joint, a sloppy coat of paint. In civil engineering you see nothing – neither the soil class nor the bedding, neither the compaction nor the position of the pipes. That is exactly why disputes arise here: if an area sinks or a pipe breaks three years later, without documentation it can no longer be clarified what caused it.

Our consequence is unspectacular but effective: we photograph every layer before it disappears, survey every new utility, prove compaction and watertightness and state in the offer which assumptions we are working on. This makes offers more extensive at first glance and sometimes more expensive in comparison. In the final bill it is the cheaper way, because the items that are listed there come as extra charges with others – and because in the event of damage you do not have to argue, you can simply look it up.

When you do not need us

For a single house connection on public land that the network operator makes itself, you do not need a construction company – there, Wien Energie or Wiener Wasser takes care of the line up to the property boundary. We take over from there, on your property and in the building.

Earthworks in Floridsdorf (1210): gravel, groundwater and large plots

North of the Danube, the ground looks different from the districts near the Vienna Woods. In large parts of Floridsdorf, below a mostly thin layer of humus, there are sandy gravels and ballast that the Danube deposited over a long time. This material is easy to excavate and easy to compact, but only of limited stability. A building pit therefore needs shallow slopes or shoring, otherwise the walls slide in. The second issue is groundwater: depending on location and season, it is comparatively high in Floridsdorf and neighbouring Donaustadt. A basement that reaches into the groundwater there needs a watertight design, and the excavation must be kept dry during the work. Also typical of the district are large residential plots in Stammersdorf, Strebersdorf or Großjedlersdorf, on which replacement buildings, extensions or pools are built. There, the price is not determined by narrow access, but by the amount of spoil and whether it can be disposed of as uncontaminated material or reused on the plot. How much excavated soil arises and where it goes is described on the page on excavation and removal.

Drainage in Währing (1180): slope water instead of groundwater

In Währing the situation is almost the reverse. Many plots in Gersthof, Pötzleinsdorf and on the Schafberg lie on a slope, and the soils there are often loamy and not very permeable. Rainwater does not seep down, but flows sideways towards the building as perched and slope water and builds up against the uphill basement wall. Drainage is designed precisely for this case: a perforated pipe in gravel and filter fleece at the foot of the wall that collects the water and drains it away with a gradient. What matters is where to. On loamy soil, a soakaway only works to a limited extent, because the water seeps away there just as poorly as at the wall. A connection to the sewer is therefore often needed, for which the discharge conditions must be clarified. Drainage also does not replace waterproofing, it only relieves it. Anyone exposing a basement wall on a slope should renew waterproofing, protective layer and drainage in one go. On steep plots, a retaining wall with backfill is often added, which itself has to be drained.

Earthworks for a plot: what happens before the house is built

Before building on a plot, a prepared building site is needed. First, the topsoil is stripped and stored to one side, because it will be needed again later for the garden and would be too good for landfill. Then follow setting out according to plan, making the building pit or foundation trenches and a gravel site road over which heavy vehicles can reach the building site even after a day of rain. Utility trenches for electricity, water and sewer are planned at the same time instead of being dug across the new garden after the shell is finished. At the end come backfilling around the building in compacted layers and the fine grading. Anyone combining these steps in one order pays for site setup and machine transport only once.

Sections and shoring: digging section by section where there is no space

In Vienna, digging often happens directly next to existing houses: for a new basement, underpinning or a sewer connection in the courtyard. A continuous excavation along the neighbouring wall would be too risky there, because the old foundation would be exposed along its entire length. That is why the work is done in sections. The structural engineer divides the wall into narrow sections, usually around one metre wide, which are excavated not side by side but staggered. Each section is immediately secured with shoring made of timber planks or trench sheets, concreted or underpinned, and only then is the next one opened. This approach takes time and manual work, because excavators rarely have space in such sections. But it is the way in which the Gründerzeit masonry next to it does not move. Working pits in utility trenches function similarly when more room is needed at a sleeve or a house connection. How foundations are underpinned is described on the page foundation reinforcement; for connections in the trench, see the page sewer construction.

Frequently asked questions about civil engineering in Vienna

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