The plasterer is booked for Monday and the sparks has not been back
Week five of a five-bedroom refurbishment. The plasterer has three men and has committed to Monday, which took six weeks to get. Four rooms are ready. The fifth is not, because the kitchen layout moved eight hundred millimetres in a showroom last Tuesday and the socket that fed the old island run now sits in the middle of a doorway. The electrician can be back on Wednesday. The plasterer cannot leave one room and return for it: a gang of three does not travel for four square metres, and the room that gets plastered a fortnight late is the room that gets its skirting a fortnight late, its floor a fortnight late, and its carpet after the fitter's next available slot, which is in three weeks.
That is the whole of programme risk in one paragraph, and notice what caused it. Nothing went wrong technically and nobody was late. A single decision arrived after the trade that depended on it, and the cost was not one day but the compounding of every booking behind it. A refurbishment programme is not a tidy order of trades — most people can write that order out from memory. It is a set of constraints of four quite different kinds, and until you can say which kind you are looking at, all of them look equally immovable and equally arguable.
Four kinds of wait, and only two of them are actually fixed
The first kind is physical, and no amount of goodwill moves it. A cable that runs inside a wall goes in before the wall closes because afterwards there is no wall to put it in. Waste pipe under a floor goes in before the floor deck, joists before the deck above them, the beam before the masonry it carries. These are not decisions. They are the only order in which the building can be assembled, and the correct response to one is to plan around it rather than to negotiate with it.
The second kind looks physical and is not: the work could be covered at any time, but somebody with a statutory role has to see it before you do. In England, regulation 16 of the Building Regulations 2010 requires notice at named stages, and requires it before the stage is covered rather than afterwards. The electrical installation carries its own version: BS 7671 requires inspection during erection for parts that will be concealed, with the Approved Document P notification behind it, and Section R109 of the International Residential Code puts the same rough inspection between the trades and the drywall in the United States. The characteristic failure is not skipping the inspection — it is booking it late, finding the visit is four days out, and losing four days on a wall finished since Tuesday morning.
The third kind is a resource. There is one plasterer, one scaffold, one drive, one skip position, one working bathroom. A resource dependency has no technical content whatsoever, which is exactly why it is missed: nothing about hanging a door prevents hanging another door, and yet the scaffold that has to stay for the roofer is the scaffold stopping the drive being laid. These are the constraints that break programmes drawn by people who thought hard about the building and not at all about the diary.
The fourth kind is not a constraint at all. It is convention wearing a constraint's clothes, and it is the only category worth arguing about. Skirting before the floor finish or after it: both work, and the choice changes who scribes to what and who carries a damaged board. Decoration before second fix or after it: most decorators want the walls done before the ironmongery and the switch plates arrive, and most electricians want the plates on before anyone paints around them. Whichever way that goes it should go deliberately, once, in writing, because the argument on site happens at the worst possible moment and is settled by whoever turned up first.
| The wait | What enforces it | What jumping it costs |
|---|---|---|
| Cable and pipework before plaster | Physical, and behind it an inspection during erection: BS 7671 for the electrical work, Section R109 of the IRC for the rough inspection generally | The wall is opened again and re-skimmed, and the patch never quite matches under a low winter light |
| Drainage seen before it is covered | Regulatory: regulation 16 of the Building Regulations 2010 names it as a notice stage | The authority can require covered work to be cut into or laid open so that it can be inspected |
| Props stay until the new concrete has strength | Physical, and measured rather than dated: ACI 347R treats form and shore removal as a strength question, as does BS EN 13670 for striking | There is no partial version of this failure; it is the one wait on the list with a safety consequence |
| Scaffold down before the driveway is laid | Resource: one drive, and standards that sit in it | Either the drive is laid twice or the scaffold comes down before the roof is finished |
| Floor finish after the second fix | Convention, and a good one, but a choice | Nothing, if it is decided once and everybody prices against the same answer |
| Skirting before or after the floor covering | Convention entirely, and it differs by floor type and by trade | An argument on the day between two people who each priced the other version |
Four doors that only open once
Rather than hold a forty-line programme in your head, hold four moments. Each is a point at which the house stops being one kind of building and becomes another, and each is effectively irreversible: going back through it costs more than everything you saved by rushing it. Every trade and every decision on the job can be sorted by which door it has to be through.
The first is the day the building is weathertight — roof covering complete, flashings dressed, windows and external doors in and sealed. Before it, everything outside is a weather bet and the scaffold is up; after it, anything needing that scaffold needs it re-erected, and the internal trades can finally be booked with confidence. The second is the day the floor structure closes. Under-floor drainage, buried water and heating pipework, any underfloor circuit, the duct that has to cross the house: all of it is a floor-up decision, and after the deck goes down or the screed is poured it is a floor-up decision again.
The third door is the one from the opening paragraph: the day the walls and ceilings are boarded and plastered. Everything that lives inside a wall has to be in, tested and seen before it — not only cable and pipe, but the noggin behind the wall-hung basin, the pattress for the television, the extract duct, the recessed shower valve, the concealed cistern frame, the acoustic infill, the fire stopping around a penetration, and the photographs of all of it that you will want in three years when somebody drills. The fourth is the day the floor finish goes down. After it, every trade in the house is working over a surface that damages, protection becomes a cost and a nuisance, and access becomes a negotiation rather than an assumption.
- Write the four dates first, before any trade is booked, and treat them as the only fixed points on the programme.
- Put every task under the last door it must be through, not under the trade that performs it.
- Circulate that list to each trade and ask one question: what of yours is on it that I have not written down.
- Set each trade's deadline as the door rather than as their slot, so a trade two days late is still inside a wait that has not begun.
- Photograph every wall and floor on the last day before it closes, from fixed positions with a tape in shot.
- Hold nothing back through a door on the assumption of a quick return; a return visit through a closed door is a different job at a different price.
The budget and the booking list are the same list read twice
There is no separate exercise called drawing up a programme. The scope list already exists — it was built to price the job — and the programme is that same list read a second time with different questions asked of each line. Where the estimate asks what does this cost, the programme asks who does it, what has to exist before they arrive, how long they need the house for, and how much notice their diary wants.
Read the material lines as deliveries: each is a lead time, a vehicle that has to get down the road, a pallet that has to stand somewhere dry, and a date after which it stops being other people's problem and starts being yours to insure. Read the labour lines as bookings, each with a notice period that has nothing to do with the size of the work — the six-week wait for the plasterer is six weeks whether the job is four rooms or fourteen. Read the fee line as applications with determination periods that run whether or not anybody is on site. Then count the handoffs: the number of times the house passes from one trade to the next predicts how a programme behaves better than the number of weeks in it, because every handoff is a place where one trade's finish and the next trade's expectation have to agree with nobody present to arbitrate.
Enter the scope as its three totals and then read the same three lines back as a calendar rather than as money — every material figure is a delivery with a lead time and somewhere to stand, every labour figure is a booking in a diary you do not control, and the permits line is an application whose determination period runs while you wait.
Total cost of all materials for the project.
Total cost of hired labor, if any.
Building permits, inspection fees, and similar required costs.
Extra buffer for unexpected costs — nearly every renovation finds at least one surprise.
Total project budget
$10,695
- Materials
- $5,000
- Labor
- $4,000
- Permits & fees
- $300
- Subtotal
- $9,300
- Contingency buffer
- $1,395
They open the calculator with your figures already in it
Renovation Budget Calculator: 10,695 USD — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
What this calculation does not cover
- Sales tax, delivery charges, tool and equipment rental, dumpster and disposal fees, and temporary storage or lodging have no field of their own — the subtotal is exactly materials plus labor plus permits, so anything else reaches the total only if you fold it into one of those three figures yourself.
- The buffer multiplies the combined subtotal, so a fixed-price cabinet order, an open-ended demolition line and a published permit fee are all padded at the same percentage; there is no way to carry a heavier margin on just the part of the job that holds the unknowns.
- If the labor figure is your own hours-times-rate estimate rather than a contractor's quote, a general contractor's overhead and profit on materials and subcontracted trades appears nowhere in the sum, which adds only the three amounts entered.
- Every set of entries returns the same high confidence, including a 0% buffer at the bottom of the allowed range or the 50% at the top, because nothing in the arithmetic examines whether the percentage chosen suits the work being priced.
- Each amount is treated as a price known today: no duration, phasing or draw schedule enters the calculation, so a project whose material prices move between quote and purchase, or whose costs straddle two budget years, is totalled as though it all happened at once.
Gravity first, then size, then whatever bends
Within the services the order is not negotiable, and it is not about trades at all. It is about how much freedom each system has. Drainage has the least: it runs to a fall, the fall is fixed by the pipe and the fixture, and BS EN 12056-2 in Europe and the International Plumbing Code in the United States both set that gradient rather than leaving it to the fitter. A soil pipe cannot be moved a hundred millimetres to miss a joist without consequences somewhere along its length, so it is set out first and everything else is designed around where it landed.
Ventilation duct comes next, because it is the largest thing in the building that is not structure and it loses performance every time it is squeezed or bent. Then the systems with real but limited freedom: gas, which is rigid, tested as an installation and awkward to reroute once jointed; then pressurised hot and cold water, which takes a detour without changing what it delivers. Cable comes last of the concealed services because it is the most flexible thing in the wall — which does not mean least important, it means the electrician can and should be asked to work around the pipe rather than the other way round.
That order has a scheduling consequence people miss. If drainage and duct are set out first, one drawing can be marked up on site by the two trades together before either has fixed anything, and the collisions get found while they are still lines. If instead each trade arrives on its own week and installs to its own idea of the route, the collisions get found by the third trade in, who then either notches a joist they should not notch or waits for somebody to come back. That joint mark-up is the highest-value half-day on the whole first fix.
- Set out below-ground and within-floor drainage first, to its gradient, and fix its position on the drawing.
- Route the largest ventilation ducts second, before anybody claims the same joist zone with something easier to move.
- Place gas next, so its rigid runs and its test regime are settled before the flexible services fill the void.
- Run pressurised water around what is already committed, taking the detours rather than asking for them.
- Cable last of the concealed services, and let it take every remaining bend.
- Get all of it marked on one drawing, on site, with the trades present, before the first clip goes in.
The week new concrete will not give back
Refurbishments contain very little concrete, and it appears in exactly the places that block everything else: the bed under a new padstone, a pad foundation for a post carrying a new opening, a patch of slab where a chimney breast came out. Each is a few hours of work sitting in front of weeks of other people's, and each has a wait attached that is set by chemistry rather than by anyone's diary.
The rule the standards apply is that the wait ends at a strength, not on a date. ACI 347R, the Guide to Formwork for Concrete, treats form and shore removal as a strength question; BS EN 13670 handles the striking of formwork and falsework the same way. Neither of them offers a number of days, because days are not the variable. Temperature is. The Nurse-Saul maturity function in ASTM C1074 makes that explicit: maturity accumulates as temperature above a datum multiplied by elapsed time, so a January pour standing in an unheated shell with the windows out reaches a given maturity considerably later than the same mix in June, and the propping stays up for the difference.
Two honest cautions about using that in a programme. A maturity index is not a strength until the strength-maturity relationship has been established for the particular mix, which ASTM C1074 sets out as a laboratory exercise, with field verification on specimens made and cured to ASTM C31 and broken to ASTM C39. And the method shortens a wait with evidence, not with optimism — on a small domestic pour, where nobody is going to instrument anything, its real use runs the other way: as the reason a cold-weather pour needs more float in front of the trade behind it, and as the argument for a curing blanket when the alternative is idle weeks.
Put in the average temperature the pour has actually held and the hours it has stood, and compare a warm week against a cold one. The index only becomes a strength once the mix's own strength-maturity relationship has been established under ASTM C1074 — so use the comparison to size the wait honestly, never to strike a prop early.
The average concrete temperature over the elapsed curing period, in °C.
The total elapsed curing time, in hours.
The temperature below which the mix gains no useful strength. ASTM C1074 recommends 0°C.
Maturity index
3,360 °C-hours
This uses a single average temperature for simplicity — a real maturity study integrates continuously logged temperature data over time, which is more accurate when temperature varies significantly during curing (e.g. cold nights, hot days). The datum belongs to your mixture: 0°C is ASTM C1074's recommendation for plain Type I cement, and Annex A1 sets out how to measure it for anything else.
- Elapsed time
- 7 days
- Datum temperature used (°C)
- 0 °C
- Temperature above datum (Δ°C)
- 20 Δ°C
They open the calculator with your figures already in it
Concrete Maturity Method Calculator (Nurse-Saul): 3,360 °C-hours — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
What this calculation does not cover
- A maturity index is not a strength. Until a strength-maturity relationship has been developed for the mix actually supplied — cylinders from that mix, broken at several ages against their own logged maturity — this number cannot be read as an in-place compressive strength, and on its own it does not release formwork, tendons, sawcutting or traffic.
- Nurse-Saul sums temperature over successive intervals; this takes one average for the whole period instead. Cold nights, the hydration peak and any spell the concrete spent below the datum are all flattened into a single figure, so the wider the temperature swing over the period the further this sits from what an embedded logger would report.
- It covers one temperature, not a position in the pour. Corners, edges, thin sections and the top surface run colder than the core and reach a given maturity later, and a striking decision belongs to the coldest critical location rather than to an average of the element.
- The datum is taken exactly as entered — nothing here checks it against your cement, admixtures or supplementary cementitious materials. The Nurse-Saul function is also linear in temperature, so it does not capture the reduced ultimate strength of concrete cured hot: a warm pour can accumulate maturity quickly and still fall short at later ages, which is what the Arrhenius equivalent-age methods exist to address.
- At or below the datum the index reports zero. That is the method's bookkeeping convention, not a verdict on the concrete: it says nothing about whether a pour that got cold or froze has been damaged, and it does not cover cold-weather protection requirements.
- The index is reported in °C-hours whichever measurement system you are reading the site in, and the two temperature rows beneath it are shown in Celsius terms for the same reason: the figure is only meaningful against the strength-maturity curve it is compared to, and that curve carries the units its own cylinders were logged in. Enter your temperatures in whichever units you measured — those fields convert — but if your calibration curve is in °F-hours, multiply this figure by 1.8 before reading a strength off it.
Water goes into the house in one week and has to come out before another
Plaster and screed are delivered dry and installed wet, and every litre of that water has to leave the building before the trades that follow can do their work properly. This is the wait most often left off a programme entirely, because nobody is on site during it and it does not look like work. It is also the wait most often shortened by a decorator being told the room is ready when what is meant is that the plasterer has left.
It helps to be exact about what is drying, because there are two different things and only one is quick. The room's air holds almost nothing: a hundred cubic metres at twenty degrees, taken from seventy per cent relative humidity down to fifty-five, gives up something like a quarter of a litre of water in total. A dehumidifier is therefore not emptying a room once and finishing. It is intercepting a continuous release from plaster, screed and everything they wetted, day after day, and its real job is to keep the air able to accept the next litre. That is why capacity alone does not shorten drying, and why a machine in a sealed room with no heat and no air movement produces a puddle in a tank and a wall that is still wet.
The substrate is the slow half and it is answered by measurement rather than by a calendar. BS 8204-1 governs cementitious levelling screeds intended to receive flooring, and the installation codes for the coverings themselves — BS 8203 for resilient floorcoverings, BS 8201 for wood and wood-based panel flooring — put a moisture criterion in front of the fitter. The North American methods are ASTM F2170, using in-situ relative humidity probes with the equilibration period the method itself specifies, and ASTM F1869, the anhydrous calcium chloride test. The numeric limits belong to the floorcovering and the adhesive manufacturer rather than to a guide, and they differ enough between products that publishing one would be actively unhelpful. For decoration the reference is the plaster manufacturer's own literature, usually the British Gypsum White Book in the UK.
So the programme entry for the floor finish is a window with a test in front of it, not a date. Write the test in as a task with its own lead time, tell the fitter at booking that their slot is provisional against a reading, and put heat and air change in the drying week rather than a bigger machine. If the finish is moisture-sensitive and the programme has no room at all, that is a specification decision surfacing as a scheduling problem, and it is cheaper to change the covering than to fight the screed.
Take a plastered room's volume, its temperature and where the humidity actually sits, and look at how little water the air alone is holding. That small number is the point: the machine is not emptying the room, it is intercepting what the fabric releases every day, so the drying window belongs to the fabric and the plant is only keeping the air hungry.
The floor area of the space being dried.
Average ceiling height — area × height is the air volume that holds the water.
Air temperature in the space. Warmer air holds more water at the same relative humidity.
What the hygrometer reads now, in %.
Where you want to hold the space — 50–55% is the usual comfort and mould-control band.
The litres-per-day figure on the unit's plate or box.
How much of the rated capacity your room's conditions actually deliver.
Water to remove from the air
0.0666 gal
This is the water in the AIR alone. Wet walls, wet contents and the continuous load from infiltration and occupants add far more over a day than the air itself holds — the pull-down being quick does not mean the job is small.
- Room air volume
- 127.41 yd³
- Water in the air now
- 0.31 gal
- Water in the air at the target
- 0.24 gal
- Pull-down time at derated capacity
- 0.43 hours
- Effective extraction rate
- 3.7 gal/day
They open the calculator with your figures already in it
Dehumidifier Water Removal Calculator: 0.0666 gal — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
Estimated cost — your price
This site holds no price list for this material — local prices vary too much to publish honestly. Enter your supplier's price and the result is costed with it.
What this calculation does not cover
- Only the water suspended in the air is counted. Moisture soaked into plaster, timber, screed, carpet and stored contents is excluded, and so is the continuous load — air leaking in from outside, ground moisture through a slab or crawlspace, showers, cooking and occupants. That continuous load, not the air's own water content, is what fills the tank day after day and what sizes the machine.
- This is not a drying-out calculation. Reaching the target room humidity does not mean a wet subfloor, wall cavity or plaster is dry; only a moisture meter in the material tells you that, and water still held in the fabric will push the room back up as soon as the unit stops.
- The pull-down time assumes a closed space with nothing adding moisture while the unit runs and a single extraction rate held constant throughout. It does not model infiltration during the run, doors opening, extraction falling as the room dries and cools, coil defrost cycles, or the unit's own humidistat cutting out short of the target.
- One temperature and one humidity are applied to the whole volume. Real spaces stratify — cold corners, outside walls, the space behind furniture and under a floor sit colder and wetter than the meter in the middle of the room, and reach the target long after it does.
- Not a condensation or mould-risk assessment. Mould grows at the surface humidity against a cold wall, window reveal or uninsulated slab, which can stay high while the room air sits comfortably at 55%. Judging that needs the surface temperature and a dew-point check, not a room average.
An extension is a front end, not a phase
Where the refurbishment includes an extension, almost everyone draws it as phase one and the house as phase two, and the job refuses to behave that way. Until the opening into the existing wall is formed they are two separate sites with separate weather exposure, separate access and separate trades, and they should run in parallel — the shell is outside, the strip-out is not, and there is no reason for the house to sit idle while a roof goes on.
The moment the wall comes out, that stops being true. From then on there is one building, one dust regime, one heating system with a hole in it, and one route every material travels. That makes the timing of the structural opening the most consequential decision on the programme, and the rule is straightforward: do not form the opening until the new shell is weathertight, because the second it is formed the whole house is relying on the extension's roof. A beam installed early to feel like progress buys a fortnight of a house that cannot be heated or secured.
Making good is the other half of this and it is the line most often left without a slot: levelling floors between old and new, plastering the junction, extending heating and lighting circuits into the new space, redecorating the rooms the opening disturbed. It belongs to neither the extension trades nor the refurbishment trades, which is precisely why nobody books it, and it lands at the end of the job where there is no float left. Give it a named slot and a named trade before the beam goes in.
Keep the shell rate to what happens outside the existing walls, and put the structural opening and the making-good in as their own figures. The non-shell share the breakdown returns is the money that lands inside the occupied house — which is also the part of the work that cannot run in parallel with anything and therefore sets the tail of the programme.
New internal floor area, all storeys.
Your rate for the extension shell and fit-out.
Beam, padstones, temporary support, engineer.
Where new meets old.
Architect, engineer, planning and building control.
Fifteen percent minimum on an extension.
As it applies in your jurisdiction.
Total extension cost
Needs your Build rate (per m²)
This page does not assume a price. Enter yours and the answer appears here.
They open the calculator with your figures already in it
Home Extension Cost Calculator — shown in imperial, US market. The link sets both, so the result they see is the one on your screen.
What this calculation does not cover
- Excludes underpinning, which is a specialist operation priced by the linear length and is only known to be needed once trial holes are dug.
- Excludes diverting a public sewer, which requires the water authority's agreement and is priced by them.
- Excludes rehousing or storage while the work runs, which on a rear extension into the only kitchen is a real cost.
Counting backwards from the factory, not forwards from the start
Ordinary stock materials are bought when they are needed. Made-to-order items are not, and on a refurbishment they are the things that decide the shape of the whole calendar: fabricated steel, aluminium or timber glazing, a staircase, a stone worktop, a bespoke shower screen, sometimes the boiler. Each is quoted with a lead time, and the only sound way to use it is to ask for it in writing and count backwards from the week it has to be on site.
The trap is the subset that cannot be ordered until something exists to measure. A staircase is made to a floor-to-floor dimension that is not final until the finished floor levels are settled at both ends. A stone worktop is templated on installed and levelled carcasses. Glazing is surveyed into openings that have to be formed first. For all of those the lead time does not begin when you decide — it begins when a surveyor can get a tape on a real building — so the decision deadline is the lead time plus the survey slot plus everything upstream of the survey.
| Item | What has to exist before it can be measured | What its arrival releases |
|---|---|---|
| Fabricated steel beam and padstones | The engineer's design, and the opening set out on the actual wall | Everything above and beyond the opening; nothing structural moves until it is in and loaded |
| Windows and external doors | Structural openings formed, and surveyed by the fabricator rather than scaled off a drawing | Weathertightness, therefore the scaffold coming down and the internal trades starting with confidence |
| Staircase made to a site survey | Floor-to-floor dimension fixed, with the finished floor build-up known at both levels | Plastering to the stairwell, the upper-floor second fix, and safe permanent access for every trade above |
| Stone or composite worktop | Carcasses installed and levelled, sink and tap chosen, template taken on site | The sink and tap connection, the splashback tiling, and the kitchen being usable at all |
| Underfloor heating manifold and floor build-up | Floor levels agreed with the screed depth and the finish thickness in the same sum | The screed pour, therefore the drying window, therefore the floor finish and the end of the job |
| Concealed shower valve and cistern frame | Nothing; the constraint is only that the actual item is on site before first fix | The wall it is buried in, which cannot be closed around a fitting nobody has yet bought |
The diaries you do not own
Several fixed points on a refurbishment belong to organisations that will not rearrange themselves around you, and the mistake is treating them as tasks rather than as bookings. Regulation 16 of the Building Regulations 2010 lists the stages at which notice must be given, and Section R109 of the International Residential Code does the same work in the United States, with the certificate of occupancy under Section R110 at the end. Read as a programme rather than as a fee, the point of that list is what it stops: nothing on it may be covered before it has been seen, and the regime carries a power to require covered work to be cut into or laid open so that it can be inspected. The same list read as payment triggers is worked through on the stage-payments page, and there is no need to build it twice.
Statutory notices with waiting periods are worse, because the period runs before anything happens rather than during it. The Party Wall etc. Act 1996 is the common one on a terraced or semi-detached refurbishment, and its periods and its deemed-dissent trap are set out in full on the party wall page; the programme point is only that the longest of them runs in months from the day of service, so it belongs on the calendar during design rather than during mobilisation. Pre-commencement planning conditions behave the same way: discharging one is an application with a determination period, and it has to be complete before work begins rather than before it finishes.
Then the network operators. A supply upgrade or a meter move is quoted by the distribution network operator or the water undertaker on their own programme, measured from a completed application rather than from a phone call, and none of it compresses because your plasterer is booked. Get those applications in during design: they cost little to make early, and they are a common reason a technically finished house cannot be occupied.
Trade by trade, or room by room
There are only two ways to organise a whole-house refurbishment, they are incompatible, and the choice gets made at the start whether or not anybody notices making it. Organised by trade, each trade comes once and does the entire house. Organised by zone, one floor or one wing goes through every trade to completion before the next is started. The table below sets out what each buys and costs.
The hybrid is what most successful jobs actually run, and it is worth being deliberate about where the line falls. The destructive and concealed work — structure, strip-out, first fix, plaster — goes house-wide, because those are the trades whose mobilisation is expensive and whose work has to be continuous to be sound. The finishing trades go zone by zone, where returning is cheap and a finished room is worth most. The line between the two is the third of the four doors: everything before the walls close is house-wide, everything after is by room.
Two constraints usually decide it for you regardless of preference. If the house is occupied through the work, there must be a working bathroom and a means of cooking at every point in the programme, and that requirement alone forces zoning on the bathrooms and the kitchen no matter what the rest of the job does. And if the work is funded in stages, the schedule of payments and the schedule of trades have to be the same schedule — which is a contract question rather than a programme one, and is covered on the stage-payments page.
| Organised by | What it buys | What it costs | When it is right |
|---|---|---|---|
| Trade — each trade does the whole house once | One mobilisation per trade, the keenest prices, the shortest total duration on site | The house is unusable from week one to nearly the end, and every delay is a whole-house delay | Empty property, or the occupants genuinely moved out for the duration |
| Zone — one area taken through every trade at a time | A liveable house throughout, contained dust and disruption, early usable rooms | Repeat visits priced as repeat visits, a longer overall programme, more handoffs to manage | Occupied throughout, phased funding, or a house too large to hold in one push |
| Both — house-wide to the plaster, zoned after it | Continuity where it matters technically, containment where it matters domestically | One genuinely hard month while the whole house is open, which has to be planned for honestly | Most whole-house refurbishments with people still living in them |
Where the float goes, and the fortnight nobody draws
Float spread evenly across a programme is float wasted: it gets consumed by whichever trade reaches it first and it is never there when the job needs it. Put it in two places instead. Immediately in front of each of the four doors, because those transitions cannot be reversed and being a day early is worth a week. And immediately after every event controlled by somebody outside the job — an inspection, a network operator's works, a made-to-order delivery, the end of a drying window — because that is where the delay originates, and float placed anywhere else does not absorb it.
Who owns that float is worth settling in writing even on a domestic job. The Society of Construction Law's Delay and Disruption Protocol takes the position that float is not the exclusive property of either party unless the contract says so, and where a contract is silent the argument surfaces at the worst moment, with both sides having quietly assumed the spare time was theirs. A sentence naming the float and saying who may spend it costs nothing at signature. BS 6079, and at the forensic end AACE International's recommended practice on forensic schedule analysis, are the references if a job ever gets that far.
The last thing to draw is the tail, which almost nobody does, and which is where refurbishments overrun most demoralisingly. After the last visible trade there is a fortnight with almost no float in it and a great many dependencies: the heating filled, vented, balanced and commissioned; the electrical installation inspected, tested and certificated; the alarm interlinked; extract fans set up and measured; appliances connected by whoever is qualified to connect them; certificates gathered from six people who have all moved to other jobs. Several of those need somebody to come back specifically, and the floor finish may still be waiting on a moisture reading behind all of it.
Draw that fortnight with the same seriousness as the plastering week, and book the return visits while those trades are still on site and still interested. The characteristic ending to a badly sequenced refurbishment is not a disaster. It is a house finished in every visible respect, occupied by people living around one unfitted floor and a folder with three certificates missing, waiting six weeks for two hours of somebody's time.
Fix these before the first trade is booked
Six things that decide whether a refurbishment programme survives contact with the first delay, all of them settled at the drawing stage and none of them dependent on anybody's price.
- The four door dates, written before any trade slot — Weathertight, floor closed, walls plastered, floor finish down. Every task on the job hangs off the last door it must pass through, and a trade running late inside a door has not yet cost you anything.
- Every dependency labelled physical, regulatory, resource or convention — Only the last two are negotiable, and only the last one is free to change. Labelling them is a half-hour exercise that ends most of the arguments a programme will otherwise have on site.
- The made-to-order list, with each lead time in writing from its supplier — And beside each one, the milestone that has to exist before it can be surveyed or templated. The decision deadline is the lead time plus the survey plus everything upstream of the survey.
- The inspection and notice bookings, made during design — Building control notice stages under regulation 16 or Section R109, any statutory notice with a waiting period, condition discharges, and the network operators' applications. All of them run on somebody else's clock.
- The drying window, entered as a window with a test in front of it — Plaster and screed release water for as long as they release it. Book the moisture test as a task, tell the floor fitter their slot is provisional, and put heat and air change in the week rather than a larger machine.
- Where the float sits, and who is allowed to spend it — In front of each door and behind each externally controlled event, never spread evenly. Name it in the contract, because silence is what turns a shared fortnight into two people who each thought it was theirs.
Opens the calculators above on one screen with the dimensions from this article already filled in. Quantities only — this site publishes no price list, because local prices vary too much to publish honestly.