A science lab refurbishment looks like a school fit-out job. It’s not. The moment you see “Vulcathene drainage” and “CLEAPSS G99 fume cupboard commissioning” in the spec, you’re in specialist territory — and the pricing has to reflect that. Underprice the M&E on a science lab and you won’t just lose money. You could lose your CLEAPSS certification, fail your Building Control inspection, and hand the school a safety-critical defect that costs ten times the saving to fix.
At RapidQS, we recently completed a full bill of quantities for the Science Room 108 refurbishment at Rodborough School in Godalming, Surrey. This post breaks down exactly what made this job specialist, why the M&E pricing was the most complex element in the BOQ, and what every contractor and quantity surveyor needs to know before tendering a science lab refurbishment in the UK.
The Project: Rodborough School, Petworth Road, Milford, Godalming GU8 5BZ
Rodborough School is a secondary school in Milford, Godalming, Surrey — part of the Weydon Multi-Academy Trust. The refurbishment scope covered:
- Science Room 108: 104.1m² — the main laboratory classroom
- Prep Room: 16.3m² — chemical preparation and storage
- Store: 5.7m² — equipment storage
- Total GIA: 126.1m²
The client was Weydon Multi-Academy Trust, the main contractor was DW Contracts (Daniel Walker), and the architect was SHW (Julia Kordes). The procurement route was JCT Minor Works with Contractor’s Design 2024 (JCT MWD 2024) — with a specific contractor design obligation applying to the mechanical and electrical package.
Our QS total: £479,858 ex VAT — for what is, on paper, a 126m² school room refurbishment. That number surprises people until they understand what’s in it.
What Makes a Science Lab Different From a Standard School Refurb
The gap between a standard classroom refurbishment and a science lab refurbishment is not a matter of degree — it’s a matter of category. Here’s what makes science labs fundamentally different:
Vulcathene Chemical-Resistant Drainage
Standard school buildings use PVC or polypropylene drainage. Science labs cannot. Every sink, every lab bench, every floor drain in a science lab needs to drain to a Vulcathene chemical-resistant drainage system — a polyvinylidene fluoride (PVDF) product specifically designed to resist acid, alkali, and solvent attack.
The cost difference is significant: Vulcathene fittings and pipe cost approximately 10× the equivalent PVC components. A simple 40mm Vulcathene trap that would cost £4–6 in PVC costs £40–60 in Vulcathene. Multiply that across every connection point in a 104m² lab with 8–10 lab bench runs, and the drainage specification alone adds £15,000–£25,000 to the M&E package compared to a standard fit-out.
Gas Interlock Systems Linked to Ventilation
Every science lab with gas services must have a gas interlock system — an automatic shut-off that cuts the gas supply if the ventilation system fails. This is not a design option; it’s a CLEAPSS mandatory requirement. The logic is straightforward: if the fume cupboard extract fails, gas at the bench becomes an immediate hazard. The interlock prevents gas flow until ventilation is confirmed as operational.
A gas interlock system is a specialist subcontract item. It cannot be included in a general plumbing package. The commissioning process involves proving the interlock logic works correctly — gas cuts at the set point, ventilation restoration restores gas supply. This commissioning needs to be witnessed and signed off by the lab installer and CLEAPSS.
Fume Cupboard Extract Ductwork to Roof
The fume cupboard extract isn’t just a fan in the ceiling. It’s a dedicated extract ductwork system that runs from the fume cupboard, through the building fabric, and terminates at roof level — high enough to ensure that hazardous vapours aren’t recirculated into the building. The system uses Variable Air Volume (VAV) controls to maintain the required face velocity at the fume cupboard sash, regardless of sash height.
Face velocity requirements under CLEAPSS G99 are specific: a minimum of 0.5m/s at the working sash position. VAV systems maintain this velocity by adjusting fan speed as the sash height changes. A fixed-volume system cannot do this reliably. This is why VAV controls are standard on modern school fume cupboards — and why they cost more than a simple extract fan.
Lab Bench Service Connections
Every lab bench position in a science lab is a services hub. At Rodborough Room 108, each bench position requires:
- Cold water supply and Vulcathene drain connection
- Gas service point (piloted or ignited, interlocked to ventilation)
- 240V electrical power (twin outlet, RCD-protected)
- Data point (for digital microscopes, pH meters, data loggers)
Multiply that across 8–10 bench runs of 3–4 positions each and you’re looking at 30–40 individual service connections per lab. Each one needs to be pressure-tested, certified, and commissioned. This is not general building services work — it’s specialist laboratory installation.
Pinnacle Specialist Furniture — PC Sum £56,773.88
Lab furniture in a science room is not the same as classroom furniture. It needs to be:
- Chemical resistant — all surfaces, including drawer interiors
- Structurally robust — lab benches need to support heavy equipment
- Service-integrated — plumbing, gas, and electrical connections terminate at or through the bench
- CLEAPSS compliant — configuration and height must meet laboratory design guidance
We included the Pinnacle specialist furniture package as a Prime Cost Sum of £56,773.88 — based on a confirmed quotation from Pinnacle. This is not an estimate; it’s a fixed PC Sum that gives the client certainty on the furniture cost while allowing the main contractor to add their attendance and profit separately.
The Vulcathene Problem — Why You Can’t Skip It
Some contractors try to value-engineer Vulcathene drainage out of a science lab spec. This is a serious mistake. Here’s why:
First, CLEAPSS guidance is clear: chemical-resistant drainage is mandatory in rooms where chemicals are handled. A building control officer inspecting a science lab will check the drainage specification. If you’ve installed PVC and it should be Vulcathene, the building won’t pass — and you’ll be replacing the drainage after it’s been installed, concealed, and connected.
Second, the long-term failure mode of PVC in contact with lab chemicals is predictable. Acids and solvents degrade PVC over months to years. You get joint failures, blockages, and ultimately a flooded lab. The remediation cost — including damage to specialist flooring, lab furniture, and M&E — dwarfs the cost saving on the original drainage specification.
Third, your professional indemnity insurance position on a non-compliant laboratory installation is not strong. Specify correctly first time.
Fume Cupboard Compliance — CLEAPSS G99, VAV, and Annual Certification
The fume cupboard installation at Rodborough Room 108 needs to comply fully with CLEAPSS G99 — the CLEAPSS guidance document specifically covering fume cupboard performance and testing. Key requirements:
- Face velocity: Minimum 0.5m/s at the working sash position (typically 200mm open)
- VAV controls: Variable air volume to maintain face velocity as sash height changes
- Ductwork: Dedicated extract, no recirculation, termination at roof level minimum 1m above ridge
- Commissioning certificate: Must be issued by the installer at practical completion and retained by the school
- Annual testing: Face velocity testing required annually — this is the school’s ongoing obligation, not the contractor’s, but you need to commission it correctly for the first annual test to pass
VAV systems add approximately £3,000–£5,000 per fume cupboard over a fixed-volume system. At Rodborough, with two fume cupboards (one in the main lab, one in the prep room), that’s £6,000–£10,000 in VAV premium — but it’s the only compliant solution.
Gas Interlock Systems — Specialist Subcontract, No DIY
The gas interlock system at Rodborough was priced as a specialist subcontract Provisional Sum. Here’s why it has to be a specialist subcontract:
- The interlock logic needs to be designed by someone who understands both the gas installation standards (Gas Safe, IGE/UP/2) and the CLEAPSS laboratory safety requirements
- The commissioning involves proving safety-critical logic — this needs to be done by the installer and witnessed by an independent party
- The O&M manual needs to document the interlock logic, the test procedure, and the reset procedure — this is a safety-critical document that the school retains indefinitely
A general plumber or M&E contractor who hasn’t installed a gas interlock before should not be attempting it on a school site. The consequences of a failed interlock in a live science lab are too serious.
The M&E Contractor Design Obligation (JCT MWD 2024)
The JCT MWD 2024 contract used on the Rodborough scheme places the design obligation for the M&E package firmly with the contractor. Specifically:
- The Pope Services Employer’s Requirements document defines the performance specification for the M&E systems
- DW Contracts, as main contractor, is responsible for ensuring the M&E design meets those requirements
- If the installed systems don’t perform to specification, the contractor carries the remediation risk — not the architect, not the M&E engineer
This has a critical implication for pricing: you cannot fix the M&E price until you have Appendix F (the M&E Employer’s Requirements) in your hand. Without Appendix F, you’re pricing against a performance specification you don’t fully understand. You will either overcost (and lose the tender) or undercost (and lose money on the job).
In our BOQ for Rodborough, Zone 6 M&E was priced at £215,320 as a Provisional Sum — pending receipt and review of the Pope Services Employer’s Requirements. This is the only intellectually honest way to handle M&E pricing under a contractor design obligation when the ER document isn’t finalised.
The Floor — Scan First, Then Price
The floor in a science lab is not a straightforward substrate. At Rodborough Room 108, the existing floor construction includes:
- Service voids beneath the floor — containing drainage, gas, and power runs to the lab benches
- Galvanised trays protecting service runs
- Two layers of Sikafloor screed — an existing screed and a repair screed applied at some point in the building’s history
Before you price floor works, you need to scan. A structural scanning survey (GPR or electrical resistance survey) maps the service voids and confirms the floor construction. Without it, you’re pricing floor preparation blind — and the risk of hitting a service void, cutting a gas line, or damaging existing drainage during mechanical preparation is very real.
We included a floor survey provision in our preliminaries and priced floor preparation based on the assumption of two screeds to remove. If the survey reveals a different floor construction, the variation mechanism in the JCT MWD contract handles it. This is better than assuming a simple one-screed preparation and finding two.
Altro Chameleon Hygienic Wall Cladding — Approved Installer Only
The wall specification for science lab areas in a modern school refurbishment typically calls for hygienic wall cladding rather than paint or ceramic tiles. At Rodborough Room 108, the specification was Altro Chameleon — a 2.5mm rigid PVC cladding system with welded joints that provides a seamless, chemical-resistant, and easily cleanable wall surface.
Three things to know about pricing Altro Chameleon:
- Approved installer only: Altro specifies that Chameleon must be installed by an Altro-approved contractor. If you include it in your supply-only package and then get a general decorator to install it, you void the product warranty and potentially the CLEAPSS compliance of the room.
- Welded joints are mandatory: The hygienic performance of the cladding depends on the joints being heat-welded, not just abutted or sealed with silicone. This requires specialist equipment and trained operatives — add to your M&E or specialist subcontract package.
- Sample approval: Architects routinely require a sample panel to be approved before full installation proceeds. Build a sample approval period into your programme.
Enhanced DBS — Every Operative, No Exceptions
As covered in our Beacon Hill article, Enhanced DBS is non-negotiable on all school sites. At Rodborough, with the additional complexity of science lab installation bringing specialist subcontractors onto site — fume cupboard suppliers, Pinnacle furniture installers, gas interlock specialists, Altro-approved cladders — the DBS management challenge is significantly greater than a standard school refurb.
Every single one of those specialist subbies needs a valid Enhanced DBS before they set foot on site. Building this into your prelims — both the cost and the lead time — is essential. We included DBS management as a specific preliminaries line item, not a footnote.
Our QS Totals — £479,858 Ex VAT
The Rodborough Science Room 108 BOQ came to:
| Zone 1 — Preliminaries | £28,450 |
| Zone 2 — Demolition and strip-out | £12,680 |
| Zone 3 — Structural works | £8,240 |
| Zone 4 — Internal finishes (walls, floors, ceilings) | £34,890 |
| Zone 5 — Specialist wall cladding (Altro Chameleon) | £18,560 |
| Zone 6 — Mechanical and Electrical (PS pending Pope Services ERs) | £215,320 |
| Zone 7 — Vulcathene drainage | £22,480 |
| Zone 8 — Lab furniture (Pinnacle PC Sum) | £56,774 |
| Zone 9 — Fume cupboard installation | £38,240 |
| Zone 10 — Gas interlock system (PS) | £18,680 |
| Zone 11 — Prep room and store works | £14,544 |
| Zone 12 — External and circulation works | £9,000 |
| Zone 13 — Contingency | £2,000 |
| TOTAL (ex VAT) | £479,858 |
At £3,806/m² ex VAT for the 126m² combined area, this is significantly above standard school refurbishment benchmarks — but it’s not a standard school refurbishment. The specialist M&E, Vulcathene drainage, fume cupboard systems, gas interlock, and specialist furniture are what drive the cost. Strip those out and you’d be at a more conventional £1,100–£1,400/m².
The Key Lesson — Never Submit Without Appendix F
The single most important lesson from the Rodborough scheme: never submit a fixed-price tender for a science lab without Appendix F (the M&E Employer’s Requirements).
Zone 6 M&E — at £215,320 — is the biggest single line item in the BOQ, and it’s a Provisional Sum. It has to be a Provisional Sum because the Pope Services Employer’s Requirements document defines exactly what the M&E systems need to do, and you cannot price contractor-design M&E without that document.
Any tenderer who submits a fixed M&E price without Appendix F has either:
- Priced it blind (which means they’ve either wildly overpriced to cover risk, or they’ve guessed and will lose money)
- Made assumptions that may or may not match the specification (which means variations at the worst possible time — after contract award)
The right answer: price M&E as a Provisional Sum, state clearly that the final M&E price is subject to receipt of Appendix F / Pope Services ERs, and build your overhead and profit on the rest of the job. Then agree the M&E price once you have the full information.
This is not a weakness in your tender. It’s intellectual honesty — and experienced academy trust procurement teams will respect it over a tenderer who submits a confident-looking fixed price that was a guess.
Pricing a Science Lab or Specialist Education Project? Get a RapidQS Cost Plan Before You Tender.
Science lab refurbishments are some of the most technically complex projects in the education sector. The combination of specialist M&E, CLEAPSS compliance obligations, chemical-resistant materials, and contractor design obligations means that a generic BOQ will either overprice the job (and you’ll lose the tender) or underprice it (and you’ll lose money).
At RapidQS, we produce specialist bills of quantities for education sector projects across the UK — from nursery schools to secondary science labs, from Surrey to Somerset. We understand the contractor design obligation under JCT MWD. We know when to use a Provisional Sum and when to fix a price. And we know that M&E on a science lab is the most expensive and most compliance-critical item in the BOQ.
Get a RapidQS cost plan before you tender your next science lab or specialist education project. You’ll tender more accurately, win more work, and avoid the expensive surprises that sink unprepared contractors.
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