In brief
A residence concept should be designed for a specific plot, with its data on the table. Before an architect starts drawing, I want to know the groundwater level and how it moves through the year, the bearing capacity of the soil, what the local zoning plan allows, how much power the grid can spare and whether a concrete truck can physically reach the site. Most of these can be checked in a few weeks, for a fraction of the design fee — and each one left unchecked comes back later as a redesign or an annex to the contract. This vetting pays off most before the purchase. If you already own the plot, I do it before the first line of the concept.
Ground first, drawings second
Let me start with the order of things, because that is where most of the problems I see on construction sites begin: first knowledge about the plot, then the concept. Not the other way round. I understand the temptation to start with the architect — that is the enjoyable part of building a house. But an architect designs on data. Where data is missing, he makes assumptions, and every assumption that later turns out false comes back to you as a redesign. That is the better case. In the worse one, it comes back during construction.
I have been repeating one sentence for years: better to know before the purchase than after. That is why I like it when someone comes to me before they buy — we check together whether what they want to build can actually stand on the land they have fallen for. Testing somebody else’s plot is not a problem: you need the owner’s consent, preferably in writing, and a preliminary purchase agreement can carry a clause that lets you walk away if the results are bad.
Most often, though, it goes differently: the plot is already there. Sometimes owned for years, sometimes bought on impulse (they liked it, and that was that — nobody asked about groundwater at the time). That is fine — I run the same set of checks, only before the concept instead of before the purchase. One thing changes: you can no longer use the results to negotiate the price.
What exactly I check, I describe below. Four things: what sits under the grass, what the paperwork allows, whether the build can be serviced at all, and the surroundings you cannot change.
What sits under the grass: soil and water
First thing: the geotechnical engineer. On a plot I am seriously considering, a drilling rig comes first. A few boreholes, sometimes probing — and we know where we stand: what layers, what bearing capacity, where the water is. For an ordinary house, two boreholes in opposite corners of the future building pass as the minimum. For a residence I want more points and deeper ones, because the structure is heavier and there is usually a basement level underneath that an ordinary house does not have. How many exactly — I will not tell you upfront; it depends on the footprint and on what the first boreholes show. The regulations do not fix that number anyway; the designer and the geotechnical engineer do. You do not need a design for this — a rough placement of the house on the plot is enough for the boreholes to land where the building will stand.
An underground level also changes the formal side. The geotechnical category of a building is the designer’s call, but a house with a basement lands in a higher category in practice — and then a basic geotechnical opinion is not enough: a soil investigation report and a geotechnical design come with it. It sounds like red tape; it works in your favour — more things get calculated before the excavator makes its first move.
Water deserves its own paragraph. The groundwater level is not a single number — it moves through the year, so one measurement can be falsely reassuring. You design for the highest level this plot can plausibly show. And if the plans include a pool or a deep-seated part of the house, the water level becomes one of the most important parameters of the whole project — what gets calculated then, and why, I described in the piece on an indoor pool with high groundwater.
And then there is the ground you cannot see, because a man put it there. Fill. One of my clients had a metre of buried slag sitting under a thin layer of topsoil — it came out only after the purchase, and one visit from a geotechnical engineer before signing would have caught it. Uncontrolled fill — the kind where nobody knows who dumped it or what it is — counts in the regulations as complex ground conditions from the start: more testing, heavier foundations, sometimes soil replacement on a painful scale. In Silesia, where I build most, there is also the mining legacy — for the regulations a separate class of conditions, for me a separate class of caution.
While the tests run, I also look at the terrain itself. An overgrown plot can look flat until it is mowed, and then the level differences turn out to be serious. A slope can be an asset — it just has to be known before the concept exists, because the zero level, the driveway and the path of rainwater all follow from it. On a clearly sloping plot that fall becomes the main theme of the project — what I check then, I wrote up in the piece on building on a slope and difficult terrain. The main threat I position a house against has been the same for years: water.
What the paperwork allows: zoning and boundaries
Second thing: the papers. You read the local zoning plan to learn what is forbidden. Height and number of storeys, roof geometry and colour, how much of the plot you may build over, how much must stay green, and the setback lines the building must not cross. A catalogue house can clash with a plan too — classically over the roof pitch — but at least its author wrote it for typical provisions. A residence is an individual design: nobody has ever checked it against anything, because it does not exist yet. So I read the plan before anything gets drawn. I had a client who did not want a garage; the local plan said otherwise — the garage had to sit within the building’s body. And so it did.
Where there is no plan, you are left with a planning decision that looks over its shoulder at the neighbourhood: new development is expected to follow what already stands around. For a residence surrounded by modest housing, that can be a very real constraint. I will not walk you through the legal procedures — I am not a lawyer; that is what your lawyer and architect are for. My role is to make sure that what you want to build does not drift apart from what is formally allowed. One thing I say from experience: the planning status of a plot can change between the day you view it and the day you decide, so I do not treat it as settled and check it once more before anything gets signed.
The base map belongs to the papers too. It shows what runs through the plot — and that can be a water main, a gas pipeline, a drainage ditch or a cable the previous owner once allowed a neighbour to lay. Around such infrastructure there are protective strips where you cannot build, or can build only conditionally, and part of these restrictions is not written into the zoning plan at all. One caveat: the maps can lag years behind reality — surveyors themselves talk about decades of backlog in the records — so whatever the paper says, the surveyor confronts it with the terrain. He verifies the boundaries while he is at it. Sounds like a formality — until it turns out the asphalt road in front of the plot actually cuts a metre and a half into it. That is exactly what happened to clients of mine.
A plot can also sit in a conservation zone, or where groundworks require an archaeologist’s supervision. Field drains can run through the neighbouring farmland — if the excavation cuts them, they have to be rebuilt (the field next door cannot stop draining just because you are building a house). And it does happen that a domestic sewage treatment plant turns out impossible or seriously constrained, because the plot lies within a protected groundwater reservoir. None of these things kills the build — but every one of them wrecks the schedule if it surfaces late.
Power and access: can this build be serviced at all
The third thing is the boring one — whether the house and the construction site can actually be powered and supplied.
I will start with power, because it is the thing people think about last and it can take the longest. You know the effect from home: kettle, oven and iron at once — and the breaker says enough. At residence scale, the same phenomenon is called grid capacity. An ordinary house asks the operator for kilowatts in the low teens. A residence with heat pumps, a pool hall that heats and dehumidifies at the same time, a sauna, air conditioning, a lift and car chargers can need several times that. And the local grid does not keep that kind of spare capacity waiting for you — sometimes the matter ends in a grid extension or a new transformer station, which means procedures measured in months. So I put the question to the grid operator at the very beginning. An answer to a standard query comes in weeks; for serious power you wait longer. I would rather know it before the architect draws the plant room.
Access. The thing you can see from the road, and hardly anyone checks it. A concrete truck with a full drum weighs over thirty tonnes. A concrete pump has to set up on outriggers and needs room for that, plus ground that will hold it — the operator has every right to refuse, and does, when he sees the machine would stand in mud. Over a narrow road, a power line can hang exactly where the boom would want to work. And on the way to many a plot stands a tonnage limit sign — then you go to the road authority for a permit. You can live with every one of these problems: there are road plates, there is reloading onto smaller trucks, there are smaller deliveries. But each of these fixes costs time and money, so I want to know about them before the price is set. With a residence there is simply more equipment and heavier: deep excavations, cranes, elements that arrive in one piece.
The neighbourhood: what you will not change
Fourth thing: the surroundings. A house can be redesigned — a plot cannot be moved. So I look at the surroundings twice.
Once at what is there: how close the busy road runs, what you hear, what you see, who has a view into the future garden. I have built near motorways a few times and I will tell you something few people believe until they stand on the plot themselves: whether you hear the motorway depends mostly on the wind. The same plot can be quiet on Tuesday and loud on Saturday. So you visit the land you intend to live on for the next few decades several times, at different hours and in different weather.
And the second look goes to what is not there yet. The empty plots around will one day be built up according to what the plan allows on them — not according to the calm you see today. If the plan next door permits tall buildings close to the boundary, in a few years you can have a neighbour in your windows. So before I believe in a plot’s privacy, I read what may be built on the plots around it.
A separate category is infrastructure on the plot itself. A client once showed me a piece of land with a medium-voltage line running across it. The seller assured him that moving it was no problem at all. I made a few phone calls — first to my own people, then to a power grid designer. The paperwork: about half a year. The cost: enough to eat up the entire attractiveness of the price. The purchase did not happen. Since then I take no seller’s word on such matters. Not because people lie — the seller simply rarely knows the weight of his own assurances.
When a plot is not worth building on
Are there plots where it cannot be done? Almost none. If something kills a build outright, it is usually the paperwork, not the ground — a zoning plan cannot be out-engineered. With water, weak soil and slopes, engineering will cope — there the question is almost never “whether”, it is “what it costs” and “whether it makes sense”.
There are, however, plots not worth building on. When special foundations, soil replacement and the fight against water grow to a point where the land next door buys you a better plot and a calmer build on top — I say so openly, with the numbers on the table. The decision stays with you. Sometimes the exact spot is worth it, because there is no second view like it; sometimes, once the costs are written out, the sentiment lets go.
One reservation, so we understand each other well: the tests remove most of the surprises. Not all of them — the ground can surprise you even after solid investigation. What I promise is a thorough vetting of the plot and an honest conversation about what follows from it. That nothing is left to discover underground — no one can honestly promise you that.
If you do not have a plot yet, I also help find one and vet it — negotiating the purchase included.
What I check before I say yes
This list is my standard for every plot meant for a residence. The results of all these points feed into the feasibility study on which I base the price — why I will not sign any figure without it, I explained in the piece on the lump-sum contract.
- Soil and water — boreholes under the planned footprint, water level with the season in mind, fill and weak soils, and in Silesia the mining history of the land.
- Zoning plan or planning decision — height, roof, coverage ratios, setback lines; planning status confirmed as of the decision date.
- Base map and boundaries — what runs through and next to the plot, protective strips around infrastructure, boundaries verified on the ground by a surveyor.
- Utilities — grid connection terms with power calculated for a residence and its systems; without a sewer — a treatment plant, provided a protected groundwater reservoir does not rule it out; without a water main — a well.
- Access and site — will a concrete truck and a pump get through, road tonnage limits, power lines over the route, room for site facilities.
- Neighbourhood — what the plan allows on the surrounding plots, nuisances today and tomorrow, sightlines into the property.
- Access to a public road — legal and physical, including how it is secured; doubts go to a lawyer before the transaction.
Questions about working with me — from the first conversation to the settlement model — I answer in the Questions section.
Frequently asked questions
Can soil tests be done before buying the plot?
Yes — and that is the right moment. You need the owner’s consent, preferably in writing; a preliminary agreement can also carry a right to withdraw if the results are bad — drafting that clause is a job for your lawyer. The tests cost a fraction of the plot’s price, and what they tell you either changes the negotiation or saves you from buying land with a problem.
How many boreholes does a residence need?
There is no single number. For an ordinary house, two boreholes across the building’s diagonal pass as the minimum; for a residence with an underground level there are more points and they go deeper, because the foundations sit deeper too. The scope is set by the designer with the geotechnical engineer for the specific footprint — which is why it helps to have at least a rough placement of the house on the plot by the day of the tests.
What if the local grid cannot supply the power a residence needs?
It happens, especially outside the city. There are two ways then: fit the house’s systems to the power the grid can actually give, or plan a grid extension with the operator — sometimes including a transformer station — and write its timeline into the schedule. The paperwork and works are measured in months, which is why I file for connection terms at the start, in parallel with the concept work.
I bought the plot without any tests. What now?
Nothing is lost — just do the tests now, before the concept. The same knowledge that could have helped in negotiations still protects the design: the architect gets hard data instead of assumptions, and the structural engineer calculates the foundations on the soil that is actually there.
This material is educational and describes how I work — it is not legal or design advice. Discuss planning and contractual matters with your lawyer and architect.
If you want your plot vetted before the concept is drawn — or want help finding one worth buying at all — let’s talk about your project.