The suspended ceiling in a 1980s office block comes down in an afternoon. What sits above it decides the next fortnight. Cast-in conduit that appears on no drawing, a redundant chilled-water run still a third full, a fire-stopping compound the asbestos survey sampled in three places and marked as presumed in twelve more. The tender priced the ceiling. The job is the void.
Soft strip demolition is the removal of everything non-structural from a building before the frame is either demolished or refurbished: partitions, ceilings, raised floors, finishes, fixtures, fittings, building services and any asbestos-containing materials that were not dealt with earlier. It stops at the structure. The definition is tidy. Pricing it is not, because most of the value in a soft strip contract sits in the parts of the building you cannot see from the floor plate.
What comes out in a soft strip, and in what order?
The sequence matters more than the list, and it is driven by one rule. Anything containing asbestos is removed before any work that would disturb it, by a licensed contractor where the material requires one. Under regulation 5 of the Control of Asbestos Regulations 2012 an employer may not begin demolition or maintenance work that could expose people to asbestos unless a suitable and sufficient assessment has been made of what is present, or asbestos is assumed to be present and treated accordingly. That single regulation puts the refurbishment and demolition survey at the front of every soft strip programme, whether or not the client has budgeted for the time it takes.
Once the asbestos is out and the air clearance is signed, the strip runs roughly like this.
| Stage | What comes out | What usually gets in the way |
|---|---|---|
| Isolation | Live services made dead and proven dead: power, gas, water, data, fire alarm, lifts taken out of service | Shared risers feeding a neighbour who is still trading |
| Licensed and notifiable asbestos | Insulation, board, coatings, gaskets, textured finishes identified in the survey | Presumed items behind finishes that were not sampled |
| Services strip | Ductwork, pipework, cable tray, containment, plant, fan coil units | Refrigerant recovery, redundant pipe still charged, cast-in conduit |
| Fit-out strip | Ceilings, partitions, raised floors, doors, joinery, floor and wall finishes, sanitaryware | Adhesives and screeds that come up with the tile, or do not come up at all |
| Fixed items | Kitchens, reception desks, tenant fit-out left behind, signage, external cladding where it is non-structural | Items the landlord says are theirs and the tenant says are not |
| Segregation and removal | Metals, timber, plasterboard, inert, mixed, hazardous streams loaded separately | One skip position, one hoist, six floors |
Read the right-hand column again. Those are the items that rarely appear in the client’s bill of quantities, and they are where the programme goes.
Where does the money go on a soft strip demolition?
Labour, mostly, and the waste behind it. A soft strip is hand and small-plant work. Its cost is set by how many people can work productively on a floor at once, how far the material has to travel to get out of the building, and how cleanly it can be segregated on the way. A building with one goods lift and a loading bay on a red route strips at a different rate from a two-storey warehouse with roller shutters on three sides, even if the two contain the same tonnage of ceiling tile.
Waste is the second line and the one with the most spread. Segregated metal earns a rebate. Segregated plasterboard has a gate fee. Mixed construction and demolition waste has a bigger one. The same building can produce three very different disposal bills depending on whether the plan lets the crew segregate at source or forces everything into one skip because that is the only position the site has. A written site waste management plan stopped being a legal requirement in England in 2013. It remains the single document that stops the disposal line running away from you.
Then asbestos, which is a subject of its own. How the licensed removal, the analyst and the enclosures move the number is covered in our piece on asbestos and demolition costs. What matters here is programme. Licensed work happens under enclosure, with notification lead times, and nothing else happens in that zone until the clearance certificate is issued. Weeks of preliminaries sit behind that sentence.
Why do soft strip tenders leak margin?
Because they are priced from the wrong documents. A contractor is handed a set of fit-out drawings from the last major refurbishment, a management asbestos survey done for the landlord’s compliance file, and a bill that lists partitions by the linear metre. The drawings are two tenants out of date. The management survey was never meant to find what a strip will disturb, and says so on its caveats page. The bill measures what someone could see on a walk-round with a tape.
Take a real shape of job. A four-storey 1990s office in a regional city, vacant, due for a full strip back to frame ahead of a residential conversion. The partition count on the drawings bears little relation to the building, because the last tenant subdivided every floor with demountable systems that were never drawn. The raised floor has two generations of cabling under it and a run of redundant pipework that turns out to be lagged. The strip is priced on the drawings and won on price. Every one of those discoveries becomes a variation claim, and the argument about whether they were foreseeable takes longer than the strip did. How those claims are valued, and why they so often end in dispute, is the subject of our post on variation orders in construction.
The leak is not the unknowns. Every building has them. The leak is pricing as if it does not, then arguing about it afterwards.
How much can you price before you open a ceiling?
More than most tenders do, and less than the client would like. Split the job into two piles.
The first pile is everything measurable from the survey and a proper walk-round: floor areas, ceiling areas, partition runs you can see, sanitary counts, door counts, the plant on the schedule, the asbestos items the refurbishment and demolition survey has identified and located. That pile can be taken off, rated and priced with confidence, and it is where an estimator’s hours should be going. It is also where assistive tooling has a measured effect. On estimating specifically, one UK construction and fit-out contractor of circa £30 million turnover cut estimating time per bid by 60 to 70 per cent with an AI-assisted approach, and narrowed the variance between estimated and delivered cost. That is a takeoff and pricing result. It says nothing about what is behind the ceiling.
The second pile is the assumptions. Presumed asbestos items and no-access areas from the survey. Services above the ceiling and below the floor. Adhesives, screeds and fixings that may or may not release. State them in the tender as assumptions, with a rate against each, so that when one proves wrong the conversation is about a quantity rather than about whether anyone should have known. A client who receives a soft strip price with a stated list of what it does and does not include is being told the truth about their building, which is rarer than it should be.
Something to try on the next bid. Before the number goes in, ask the estimator to list the ten things about this building nobody has checked. If the list is short, the survey was good or the building is simple. If the list is long, the price is a guess with a margin on it.
Is a soft strip demolition covered by CDM 2015?
Yes. Demolition and dismantling are construction work under the Construction (Design and Management) Regulations 2015, and a soft strip is no exception. If the project will run past the notification thresholds the client must submit an F10 notification to HSE before the construction phase begins. The principal contractor needs a construction phase plan before work starts. Regulation 20 requires the arrangements for demolition or dismantling to be recorded in writing before that work begins. On an occupied or part-occupied building the plan has to deal with segregation from the people still using it, which is where most soft strip incidents originate.
A soft strip on its own does not usually trigger a Section 80 demolition notice under the Building Act 1984, because the building is not being pulled down. Where the strip is the first phase of a full demolition, the notice period runs alongside it and is worth starting early. Our guide to the Section 80 notice sets out the timings.
Frequently asked questions about soft strip demolition
Is soft strip the same as strip out?
Near enough. Strip out tends to mean a tenant fit-out being removed at lease end, usually leaving services and ceilings in place. Soft strip usually goes further, back to structure, ahead of demolition or a heavy refurbishment. The trades overlap almost entirely.
Do you need an asbestos survey before a soft strip?
You need a refurbishment and demolition survey, not a management survey. A management survey is designed for a building in normal use and will not have looked inside the fabric your crew is about to open. HSE guidance is clear that all asbestos-containing materials should be removed, so far as reasonably practicable, before major refurbishment or demolition starts. A pre-demolition audit covers the wider material picture, but it does not replace the asbestos survey.
Who carries out soft strip demolition, the demolition contractor or the main contractor?
Either, and the answer changes the risk. On a demolition contract the soft strip is part of the demolition package and the demolition contractor owns the sequencing. On a refurbishment the main contractor often lets it as an early works package, then discovers the strip has exposed conditions the design team has not yet seen. Whoever holds it, the survey and the assumptions list should be shared with whoever comes next.
How long does a soft strip take?
Nobody can tell you without the survey and a walk-round, and anyone who quotes a duration per floor without those has not priced your building. Access and asbestos set the pace, along with how many people can work a floor at once.
What happens to the material from a soft strip?
Metals are sold. Timber, plasterboard and inert material go to recovery where they have been kept apart. Mixed loads go to a transfer station at a higher gate fee. Asbestos goes to a licensed site under a consignment note. The proportion in each of those streams is decided on site by whether segregation was planned for, not by the waste contractor.
Surtori works with demolition contractors on the estimating, planning and site documentation that sit underneath jobs like this. You can read more about that on our operational efficiency for demolition contractors page, or book a discovery call to talk through a live tender.