In brief
Changes will happen — over two years of building you will see things you did not consider at the start, and you will want some of them in your own home. I’ve never seen a build with no changes at all. The only question is how a change gets onto site. With me it goes one route: first I stop the affected work, so nobody seals it inside a wall; I check what it touches, and if it moves the structure or the approved design it goes to the designer before anything is built; I show you a price together with its effect on the sequence of work; you decide in writing; and at the end we update the documentation. Who pays depends on where the change came from: your decision to change the scope is on you, my mistake is on me, and whatever sits in the ground we survey before the price and describe in the contract. I will also tell you when I advise against a change.
A change is a normal part of building
When we sign the contract, we have a full set of drawings and a written scope. It looks like a closed matter, and for a while it is. Then the build starts, months pass, and in that time you are living your life — you visit friends, stay in hotels, look at other people’s interiors. At some point it turns out the dressing room could be bigger, that the living room could use one more window, that the boiler room would be better moved. That is not a whim, and not a sign the design was poor. Over two years your perspective shifts — you see other houses, other solutions — and some of those ideas are simply good.
So I do not fear changes and I do not treat them as breakdowns. I treat them as part of the process, and that part has its own procedure. And the procedure matters more than the change itself, because it decides whether the whole thing ends as a correction on a drawing or as chiselling out a finished wall.
One route: how a change gets onto site
Every change, small or large, follows the same path. Let me set it out step by step, because that is where you can see whether a change is being handled fairly.
First I stop it — the affected work, not the whole build. It sounds trivial, and it is the most important move: I take that item out of the work queue so nobody closes it inside a wall before we work out what it means (on a build, one day is enough for a “small thing” to disappear under plaster). The same change raised the day before a section is plastered and the day after it are two different bills — and sometimes that gap can no longer be recovered.
Then I check what it touches. This is where the real work begins, because in a residence hardly any change ends where it started. Moving a partition wall can look like a detail until it turns out that upstairs it changes the load on the floor slab, or clips a service run — and not every wall can be relocated without the structural engineer’s check. If a change touches the structure or the approved design, it goes to the designer and the structural engineer before it reaches site — they qualify it and, if needed, draw a variation. Nothing like that happens on a whim. Only once I know what else the change affects — structure, building systems, schedule — can I tell you what it costs.
And then you get a price — broken into parts (materials, labour, taking out what is already built, doing it again), and next to it a second thing: what the change does to the order and timing of the work. On a build, cost and time do not move together — a change can be cheap and still push the site back by weeks, because you have to wait for something to dry or cure. Where those pauses come from I describe in the piece on why building a residence takes about two years. You see both before you decide.
You decide in writing — what changes, what it costs, what it does to the schedule. Not “over the phone”, not “we’ll sort it out somehow”. A change known only as “we agreed on it at some point on site” becomes a dispute six months later, because everyone remembers it a little differently.
At the end it returns to the documentation — this time as a record of what was actually built, not of the original design. Without that, in a year nobody knows what is inside that wall. This is not bureaucracy. It is exactly what lets the house be safely altered or repaired twenty years from now.
Who pays for what — and why
The most common question about changes is “who pays for this”. There is no single answer, because the bill falls according to where the change came from.
If it comes from you — you want something other than what we agreed — you pay for it. This is no reproach and no penalty: we agreed a specific scope for a specific price, and you are widening or rearranging that scope. The price follows, after an open quote and your written approval, before anyone starts work.
If it is my mistake — something was done contrary to good practice or to what we agreed — I pay. The repair sits inside the contract price and we do not turn it into an amendment. Running this build is my trade; if I get it wrong, that is my cost, not yours. It follows directly from the way I settle the whole build — the lump sum, where I carry the cost risk within the agreed scope.
That leaves the third thing, the hardest: what you cannot see before you start. Ground that turns out different from the survey, water where none was expected, something buried below. That is why we run the ground and soil investigations before the price, not after — so the risk can be named and priced before you sign. For what genuinely cannot be foreseen, an honest contract sets out the mechanism up front: what counts as an unforeseen condition, how we show it and how it is priced — also before you sign. Investigations do not erase surprises, but they let us price the known risks earlier, before they land in the middle of an excavation.
In contract language and site practice these situations have names — additional works, substitute works, works that turn out necessary — and they differ in ways that can decide who pays. To simplify: doing more than was in the contract is one thing, and doing the same thing differently from the design is another. I am not a lawyer and I will not rule for you here where exactly those lines run — that is what your lawyer is for at the contract stage, and a good contract simply spells these cases out. What I care about is a practical rule I hold regardless of the labels: nothing moves without a price and your approval before it is done.
A comparison from outside building helps. A tailor works the same way: if you ask for a different collar after the fitting, you pay for the alteration, because you changed the order. But if the tailor sewed the seam badly, he redoes it at his own cost. What decides who pays is not the amount of work — it is which side the decision or the mistake was on.
The point where a change stops being a change
There is a line on a build worth knowing about early, because after it the bill for a change jumps. While the change is still on the drawing, it is a pencil correction — a few hours of the designer’s work and that is it. Once the wall is standing, with pipes, cables and heating running through it, the same correction starts with demolition. And here is the heart of the question about work already done: it does not vanish for free. Someone built it, someone paid for it — and now you pay a second time to take it out and a third time to build it again. When I price a late change, those three bills are simply in it.
Some decisions even have a last moment. From the houses I have built, I know that the finished floor level, the size of the windows, the layout of the walls have to be settled within a specific window of time. Reducing a window once the opening is already bricked up is extra, needless work; moving a wall that already has cables in it can mean half a room to chisel out. So with every change I say what it costs and whether we are still before that moment or past it.
And finally there are decisions you cannot reverse without demolition that makes no sense: the basement level, the run of the main structure, things poured in concrete at the start. For those my answer is sometimes plain — we will not move that now, we can at most work around it. I would rather say so than promise, and have you looking at a compromise six months later.
When I advise against a change — and what I don’t promise
Not every change you ask for will I carry out without a word. Some of them I advise against.
I advise against it when the cost stops making sense against the effect. Sometimes a small cosmetic tweak lands so late, or so deep into finished work, that its price and time are wholly out of proportion to what you actually gain. I say so plainly — that the same impression can be had more simply, or that at that cost a simpler layout gives you nearly the same thing at half the risk. The decision stays yours — it is your house and your money — but it is made knowingly, with the cost and the time counted.
In my experience, part of the changes fall away once the full price is on the table, cost and time together. When you can see the whole bill, some ideas turn out not to be as important as they looked in your head.
What I do not promise: that every change is possible and that every one is cheap. It varies. Nor do I promise that none will come up along the way — they will, and more than one. You will see the cost and the schedule effect of every change in writing, before you approve it.
What to ask a contractor about changes on site
Ask these of anyone you build with — me included. The answers will quickly tell you whether changes are a process for them or improvisation:
- How do you raise a change, and what happens to it before anyone picks up a tool?
- Is every change priced before it is done — and is the price broken into parts rather than given as one figure?
- At the quote, will I see the effect of the change on the order and timing of work, alongside the cost alone?
- Who pays for repairing an execution error?
- Do changes that touch the structure go to the designer before they are built, and do they return to the documentation?
Three answers should put you on alert: “we’ll sort it out and settle up” with no price up front, “a small thing, nothing to discuss” about a change that touches the building systems, and silence on the question about documentation. Each means the same thing — that you will learn the cost of the change only from the invoice.
Questions about working with me — from the first conversation to the settlement model — I answer in the Questions section.
Frequently asked questions
Can every change be made during construction?
Not every one, and not at every stage. While the change is still on the drawing, it is cheap and simple to check — though even then it has to pass through the structure, the regulations and the budget. The deeper into finished work, the more has to be taken apart first, and some decisions — poured in concrete or closed inside the structure — cannot be reversed at all. So with every change you hear two things from me: what it costs and whether we are still before its last moment.
Who pays for a change on site — the client or the contractor?
It depends where it came from. A scope change at your request you fund, after a prior quote and a written decision. Repairing an execution error is on the contractor and sits inside the contract price. Situations from the ground and from existing conditions we survey before the price and describe in the contract, so it is clear who takes them on before they appear.
Does a change always raise the price and extend the build?
Not both at once, as a rule. A change can be cheap and still push the schedule back — or the other way round. So with each one you get two figures: the cost and the effect on the order of work. Sometimes the second one decides, because some things on a build you simply have to wait out.
What is the difference between additional works and substitute works?
In short: additional works go beyond what was in the contract — you do something that was not in the scope before. Substitute works reach the same result by different means than designed — a different material or technology for the same outcome. That distinction can weigh on the settlement, so go through its consequences in your specific contract with your lawyer. With me, whatever the label, one thing holds: a price and your approval before the work is done.
This content is educational and describes how I work — it is not legal advice. Discuss the shape of your own contract and its provisions on changes with your lawyer.
If you want to check which decisions in your project need to be settled now and which can still wait — we start with a feasibility study, and you are welcome to bring your architect or advisor to the conversation. Let’s talk about your project.