Demolition and strip out is the only trade where the price is decided by what you cannot see. A wall is either load bearing or it is not. The ceiling either contains asbestos or it does not. The services either run where the drawing says or somewhere else entirely.
That is why the order of work in a demolition estimate is survey first, quantity second. Anyone who prices a strip out from a photograph is quoting a guess with a professional looking layout.
The surveys that matter are short and cheap: a walk round with the client, an opening up in one or two places, a check of the service routes at the meter and the stopcock, and an asbestos survey where the building age makes it relevant. An hour of that removes most of the risk from the number.
Demolition quantities fall into four groups:
A takeoff that only uses cubic metres is a takeoff that cannot be priced, because most of the labour in a domestic strip out is in the units and the linear items. Lifting 40 radiators, 12 doors and 6 kitchen units is hours of work that weigh almost nothing.
These are different jobs with different rates, and they should never be averaged.
Soft strip is removing everything that is not part of the structure: partitions, ceilings, finishes, fittings, services, non structural cladding. It is labour intensive, dusty, and slow, with a small plant requirement.
Structural demolition is taking out walls, floors, roofs and foundations. It needs plant, temporary works, and frequently an engineer. A machine that takes out a wall in an hour cannot be compared with a two person gang stripping a room in a day.
On a refurbishment, the split is usually 70 to 80 percent soft strip. On a demolition to slab, it is the other way round.
Work through it room by room, because that is how the work is done:
Then add the things that are not in any room: loft insulation, tanks in the roof, an old boiler, an oil tank, and any external item such as a shed or a fence.
Demolition waste expands. Brickwork that occupies one cubic metre in a wall occupies 1.3 to 1.5 cubic metres once it is in a skip, because the voids between pieces are filled with air. Plasterboard is worse, at 1.5 to 2.0, and insulation worse still.
The conversion from measured volume to skip count is therefore not division, it is division plus a factor:
A typical domestic strip out of a three bedroom house produces 12 to 20 cubic metres of mixed waste, which is 30 to 45 cubic yards in imperial, or roughly four to six skips. Estimating three skips is the most common way demolition quotes come up short, and the fifth skip is never in the original price.
Any building constructed or refurbished before the year 2000 should be treated as containing asbestos until a survey says otherwise. Textured coatings, ceiling tiles, insulation board, cement sheets, floor tiles and pipe lagging are all common locations.
Three things belong in the estimate and the conversation:
A demolition price quoted without an asbestos position is a price with an unquantified risk in it, and the client is carrying that risk whether they know it or not.
Some buildings contain value: slates, bricks, timber beams, cast iron radiators, fireplaces, doors. A salvage credit reduces the net cost, and it is worth checking whether the client wants the items kept, sold or given away.
Two cautions. Salvage takes time, and time is the same cost whether the item is sold or skipped. And resale values are lower than clients expect, so a fireplace that looks valuable may be worth less than the labour to remove it carefully.
The honest approach is to list the salvageable items, price the labour to remove them intact, and show the credit as a separate line with a stated assumption.
Typical outputs for domestic strip out, with a two person gang:
Structural demolition with a machine is a different scale entirely: a small excavator with a breaker will take out a single storey extension of 30 m² in a day, given room to work and somewhere to put the spoil.
A three bedroom semi, strip out for refurbishment, keeping the structure:
Two people, at those outputs, would take six to eight working days. The skips cost more than the labour. That ratio is normal for a strip out and it is why an allowance for waste is the line most likely to be wrong.
Demolition is the trade most likely to generate a complaint, and complaints cost time.
Dust control is a method statement rather than a product. Sealing the room, negative pressure with an extractor and a filter, dampening rubble before it is moved, and bagging rather than barrowing are all standard and all cost something. On a plasterboard strip out in an occupied house, dust control can add 15 percent to the labour.
Noise has hours attached to it, usually set by the local authority. Breaking concrete in a residential area is often restricted to weekday daytime, which turns a one day job into a three day job with the same plant cost spread over more days.
Party walls are the other classic. Work that affects a shared wall needs notice, and sometimes a party wall award, before anything is removed. That is a fee, a delay, and a legal requirement that has nothing to do with construction method.
Every strip out starts with the services and ends with a certificate or a permission to reconnect. The order matters.
The supply is isolated by the utility, not by the builder, on most domestic jobs. Water is turned off at the stopcock and drained, electrics at the consumer unit with the main switch locked off, gas by the supplier. Then the isolation is proved, usually by trying to use the thing you have isolated.
Skipping the proof step is how people cut a live cable that was on a different circuit from the one that was switched off. It happens more often than anyone admits, and it is the single most dangerous moment in a refurbishment.
Reinstatement is the mirror image and belongs in the estimate: new supply connections, meter changes, a new consumer unit, and the certificates that go with them.
A strip out is not a demolition if part of the building survives, and the surviving part needs protection.
Stairs take the most punishment and are the most expensive to repair. A temporary hardboard or ply protection costs little and saves a refinish. Cornices, fireplaces and original joinery need casing, not sheeting. Floors need protection where barrows run, which is every route from the skip to the work.
The cost of protection is a line in the preliminaries, and the cost of not protecting is a variation in week three that the client did not budget for. It is the easiest argument in the trade to win, and yet the line is missing from most strip out quotes.
Demolition sets the programme for everything after it, and two decisions made early have a large effect.
Whether the strip out is done in one pass or room by room changes the waste handling, the protection and the access. A single pass is faster and creates a period where the building has no ceilings, which matters if the client is living there.
Whether the structure is exposed before the new work starts decides how long the building is open to weather. On a roof strip, that window should be days, not weeks, and the new covering should be on site before the old one comes off.
Waste from construction is regulated almost everywhere, and the regulation lands on whoever produced it. Two documents matter: the licence or permit of the carrier who takes it away, and the record of where it went.
Keeping both is not paperwork for its own sake. A fly tipped load traced back to a site is a prosecution risk for the client and the contractor, and the only defence is a record showing a licensed carrier and a legitimate destination.
Sorting on site reduces cost as well as risk. Clean rubble, clean timber, plasterboard and general waste attract different charges, and mixed waste is the most expensive per tonne. A skip that is sorted is cheaper than three skips that are not.
How many skips does a house strip out need? Four to six for a three bedroom house, depending on how much is masonry and whether plasterboard is separated.
Why does demolition waste take more skips than the volume suggests? Because rubble and light waste bulk up once broken out. Multiply by 1.4 to 2.0 depending on the material.
Do I always need an asbestos survey? For any building from before 2000, before work starts, yes. It is cheaper than the alternative by a very large margin.
What is the difference between soft strip and demolition? Soft strip removes everything non structural. Demolition removes the structure itself.
Can I keep the bricks or slates? Often yes, and it is worth asking. Price the labour to remove them intact and show any credit separately.
How do I price a wall I am not sure is load bearing? Open it up, or get an engineer to look. Pricing it as non load bearing is the expensive way to find out.
The FRELUX demolition and strip out calculator measures areas, volumes and units, applies bulking factors to give a skip count, and prices disposal, plant and labour from your market's price book.