Cladding and high-risk buildings: what you need to know about rebuild costs

Building Safety Act 2022: new requirements & rebuild cost implications

In the wake of the 2017 Grenfell Tower fire, the Building Safety Act 2022 (BSA 2022) introduced sweeping changes to improve building safety. The Act created a stricter regulatory regime for the design, construction, and occupation of buildings, particularly Higher-Risk Buildings (HRBs). An HRB is defined as a building at least 18 meters tall or with 7+ storeys, that contains 2 or more residential units. Hospitals and care homes are included in the design-phase rules, though some other facility types (e.g. offices, hotels) are exempt. Key elements of BSA 2022 that affect rebuild cost considerations include:

Enhanced Fire Safety Features: New high-rise residential buildings must now incorporate robust fire protection measures (e.g. non-combustible external materials, sprinklers, improved alarms). Notably, since late 2018, there has been a ban on combustible external wall materials for new buildings over 18m, meaning future rebuilds must use fire-safe cladding and insulation even if the original construction did not. These safer materials and systems often cost more than the older, potentially combustible components they replace.
“Gateway” Approval Process: The Act implements a three-stage Gateway regime for HRBs, adding rigorous checks at planning, pre-construction, and post-completion. For example, Gateway Two (pre-construction) is a “hard stop” – building work cannot start until the new Building Safety Regulator signs off that the design meets all functional building regulations. This forces any rebuild of a high-risk building to fully comply with today’s stricter standards before ground is broken. Compliance may require design modifications (for instance, safer stairwell layouts or fire-resistant materials) that increase construction costs.
Mandatory Second Staircases: Fire evacuation standards have tightened. As of 2024, the government confirmed that all new residential buildings over 18m will be required to include at least two separate staircases by 30 September 2026. This aligns with the HRB threshold and is aimed at improving escape routes. For rebuild cost assessments, this means that if a tall building (e.g. a 20-storey tower) were destroyed and had to be rebuilt, the new design must incorporate a second stairwell (and possibly accompanying elevator shafts, lobby refuges, etc.). The additional structural and space requirements can significantly raise the rebuild cost compared to the original single-stair design.
Upgraded Fire Systems: New regulations also mandate features like automatic sprinkler systems and enhanced smoke ventilation in many buildings above certain heights or uses. (For instance, sprinklers are now required in new residential buildings over 11m tall under updated fire safety guidelines.) Similarly, more robust fire compartmentation and fire-fighting equipment access may be needed. Each of these improvements, while life-saving, adds to the material and installation costs that a rebuild assessment must account for.

Implications for Rebuild Cost Assessments

Inspector in helmet and vest examines a tall building against a clear blue sky, holding a clipboard and pen, appearing focused.

All these post-Grenfell legislative changes mean that the cost to reinstate a building after a total loss today is often higher than it was prior to 2017. A rebuild will need to meet current building regs and safety standards, not the bygone standards under which an older building may have originally been constructed. As a result, professional Rebuild Cost Assessments (RCAs) now explicitly account for compliance with current legislation when estimating sums insured. An RCA must allow for rising costs due to compliance with current building legislation. In practice, this means RCA surveyors add cost contingencies for features like modern fireproof cladding, sprinkler retrofits, secondary escape stairs, upgraded alarm systems, etc., ensuring that the insurance sum insured is sufficient to rebuild to modern safety standards. Failure to incorporate these could leave a building underinsured and unable to be lawfully rebuilt in a total loss scenario.

Rebuild Cost Assessments vs. Cladding Identification Services

It’s important to understand what RebuildCostASSESSMENT.com’s service covers – and what is outside its scope. In particular, clients and brokers should not confuse a Rebuild Cost Assessment with a cladding or external wall fire safety survey. They are very different services.

Rebuild Cost Assessment (RCA)

An RCA (also called a reinstatement cost valuation) determines how much it would cost to completely rebuild a property from scratch, usually for insurance purposes. The surveyor’s focus is on construction quantities, materials, and costs – measuring the building, noting construction type, finishes, fixtures, etc., and applying current cost rates.

Purpose: Ensure the building is insured for the correct reinstatement value (so neither underinsured nor overinsured).

Scope: RCAs consider physical dimensions, general construction specification, and include allowances for demolition, debris removal, professional fees, and compliance upgrades. Crucially, it assumes a total loss rebuild to current standards, but it does not assess whether existing materials are safe or code-compliant today. The RCA is an external, non-intrusive survey; the surveyor will observe the building’s exterior and accessible areas to note what materials are present but will not perform destructive testing. The output is a report with an estimated rebuild cost figure, not a pass/fail safety judgment.

External wall (cladding) assessment

Construction worker in orange vest and hard hat aligns cladding on a wall. Urban setting with blurred buildings and sunny sky in background.

A cladding or External Wall System (EWS) survey is a fire safety investigation of the building’s exterior walls, cladding, balconies, and insulation. A qualified fire engineer or facade surveyor examines how the wall components perform together in terms of fire spread and safety. This often involves intrusive testing (opening up sections of the facade) and lab analysis of materials. They will identify if any cladding or insulation is combustible or installed incorrectly, and then issue a report, often culminating in an EWS1 form for the building.

Purpose: To certify the fire risk level of external wall materials for lenders, insurers, and resident safety.

Scope: It is solely focused on fire safety of the external envelope – reviewing cladding panels, insulation, fire breaks, cavity barriers, etc. The assessor may recommend remediation (e.g. removal of unsafe cladding) if hazards are found. The outcome is a rating (e.g. confirming no dangerous materials, or identifying needed remedial work), not a cost estimate to rebuild the entire structure. In short, an EWS/cladding survey answers “Is this building’s cladding safe, and if not, what needs fixing?” whereas an RCA answers “What would it cost to rebuild this building in compliance with current codes?”.

Outside RCA scope: cladding identification

Given those differences, cladding identification is strictly outside the scope of an RCA service. RebuildCostASSESSMENT.com’s assessors will note the type of construction for cost purposes (for instance, whether a building has stone or brick may affect rebuild cost per m²), but they do not assess the combustibility, cladding type or fire safety compliance of that cladding. They will not issue an EWS1 form or any façade safety certification as part of an RCA. This distinction is critical for brokers to communicate to clients: ordering an insurance valuation will not address any concerns about whether a building’s cladding meets post-Grenfell safety criteria. That requires a separate fire engineer report.

To illustrate, think of the RCA as financial analysis and the cladding survey as safety analysis. Both involve the building’s construction, but they have different expert focuses and end goals. Maintaining this distinction helps manage client expectations and ensures the right professional is engaged for each need.

Why our surveyors don’t comment on cladding or EWS issues

Red prohibition symbol over a modern metal grid facade with vertical slats. The symbol signifies a no-go zone, representing the fact that RCA cannot comment on cladding safety for buildings.

RebuildCostASSESSMENT.com’s surveyors must not provide opinions on a building’s external wall fire safety, cladding type or cladding compliance, and there are strong professional reasons for this policy. Even though cladding problems have huge cost implications, our surveyors deliberately stay in their lane of expertise (rebuild cost valuation) and refrain from giving cladding safety advice. The reasons include:

Professional Competence and Training: Determining whether an external wall system is safe requires specialised fire engineering knowledge and often a specific qualification (such as the RICS Level 6 Award in External Wall System Assessment).
- Our RCA surveyors are experts in construction costs and building pathology for valuation, but are not accredited fire engineers or facade inspectors. It would be beyond their professional competence (and a breach of RICS standards) to pronounce a cladding system safe or unsafe without the requisite training.
- RICS emphasises that a normal survey or valuation inspection “is not sufficient to establish whether or not a wall system contains combustible materials… which facilitated the spread of fire”. This is outside the expertise of an insurance valuation surveyor, and RICS created the separate EWS1 process precisely so that competent experts would handle those investigations. In short, our surveyors stick to what they know best – construction costs – and leave fire safety judgments to the appropriate specialists.
Insurance (PII) Limitations: Like all RICS-regulated firms, RebuildCostASSESSMENT.com carries Professional Indemnity Insurance (PII) to cover our services. However, since 2020, the PII market has severely restricted coverage related to cladding advice. In fact, RICS altered its minimum policy terms in May 2020 to allow insurers to exclude liability arising from EWS1 cladding assessments. As a result, most surveying firms’ PII does not cover giving advice on combustible cladding or signing EWS1 forms (unless they have a special policy rider). If our surveyors were to comment on an external wall’s fire safety and later a problem arose, both the firm and the individual could be personally liable without insurance protection. This is an unacceptable risk. Adhering to our insured scope (reinstatement cost advice only) ensures we don’t inadvertently void our cover or expose ourselves to litigation over fire safety issues that our service was never meant to address.
Regulatory and ethical compliance: RICS’s code of conduct mandates that members must only practice in areas where they are competent and appropriately insured.
- Offering informal cladding opinions could violate these rules and jeopardise the surveyors RICS registration.
- Moreover, misstatements about cladding can have life-safety consequences; it would be unethical for an unqualified person to declare a building “safe” or otherwise based on a superficial look.
- Our surveyors, therefore, include clear disclaimers in RCA reports that no assessment of external wall fire safety has been undertaken. This transparency protects all parties. We empathise deeply with owners concerned about cladding (indeed, many clients are understandably anxious post-Grenfell), but we must guide them to the proper channel rather than overstep our role.

Bottom line: RebuildCostASSESSMENT.com focuses on delivering a trusted, professional, and accurate rebuild valuation. We do not compromise that integrity by wading into cladding evaluations, which are a different discipline. This approach ultimately best serves our clients – they get sound insurance advice from us, and we help point them toward qualified fire engineers when needed.

Directing clients to qualified cladding professionals

Laptop displaying RICS surveyor website. Visible sections: "Buying a property?" and "Find a surveyor."

When cladding or external wall fire safety concerns do arise, brokers and property managers should help clients engage the right experts for that job. Fortunately, there are established resources to find qualified professionals who specialise in External Wall System assessments:

RICS Find a Surveyor – external wall survey specialists: The Royal Institution of Chartered Surveyors hosts an online directory to locate firms by service and region. Using the RICS “Find a Surveyor” tool, one can search for surveyors offering External Wall Surveys or Fire Risk Appraisal of External Walls.
- These will be surveying professionals with specific fire safety expertise, often chartered building surveyors or fire engineers who have undergone additional training for cladding assessment.
- According to RICS, an external wall survey should be undertaken by a “qualified surveying professional” reviewing all aspects of the wall system (cladding, insulation, fire-stopping, etc.).
- Brokers can confidently refer building owners to this resource, ensuring they find an accredited firm rather than unverified consultants.
Level 6 external wall system (EWS) surveyors: In response to the cladding crisis, RICS and other bodies have implemented rigorous training programs for professionals in this niche.
- One benchmark credential is the Level 6 award in external wall system assessment, an Ofqual-regulated qualification (administered by ABBE) that certifies an individual to conduct fire risk appraisals of external walls and sign certain EWS1 forms.
- When seeking a consultant for cladding issues, look for this Level 6 qualification or equivalent (many will proudly list it in their credentials). Possession of the Level 6 Award indicates the person has been assessed on fire engineering basics, material science, and has practical skills to investigate cladding safely.
- RICS maintains a list of professionals who have completed its EWS Assessment Programme – this can be a good reference to verify expertise. Engaging a Level 6 qualified surveyor or a chartered fire engineer gives clients the assurance that the advice on their cladding will be competent and insured.
Other resources: Aside from RICS, industry associations like the Institution of Fire Engineers (IFE) also provide directories of registered fire engineering professionals. The UK Fire Risk Assessors Register or schemes like UKAS accreditation for Fire Risk Assessors are additional marks of quality. Brokers may also contact the local fire brigade for guidance or consult the government’s consolidated advice notes for building owners. However, as a starting point, RICS’s platform is designed to connect stakeholders with reputable firms familiar with the latest Government guidance and EWS1 process.

By steering clients to the proper experts brokers add value and demonstrate a duty of care. It ensures that issues like combustible cladding are evaluated thoroughly and any remedial costs (which can be substantial) are identified by those qualified to do so.

We at RebuildCostASSESSMENT.com consistently advise clients: if you have concerns about your building’s cladding or external wall system, engage a specialist and obtain an EWS1 assessment if appropriate. This not only addresses safety and regulatory compliance, but can also feed into a more accurate rebuild cost once any required remediation is understood.

Impact of new building legislation on high-risk building costs

Post-Grenfell building safety reforms have not only changed procedures – they are materially changing construction practices and costs, especially for high-rise and “higher-risk” buildings. Brokers dealing with insuring such properties should be aware of how recent legislative changes drive up rebuild values:

High-risk building status: As defined earlier, HRBs (≥18m or 7+ storeys with residential use) now fall under an intense regulatory spotlight.
- Owners of existing HRBs must register them with the new Building Safety Regulator and comply with ongoing safety case requirements.
- In terms of rebuild cost, being an HRB means any reconstruction must incorporate features to satisfy the regulator and new regulations. For instance, more robust structural fire protection (fire-resistant floors, protected escape lobbies, etc.) may be required. These elements increase the per-square-metre cost.
- Also, contractors rebuilding an HRB will face stricter oversight, likely meaning more meticulous (and thus costly) construction methods to pass regulator inspections. All of this contributes to higher rebuild costs per unit area for HRBs compared to similar-sized buildings that are not in scope.
Gateway regulations and approvals: The introduction of Gateways has effectively front-loaded many safety-related costs into the initial design and construction phase.
Gateway One (planning stage) forces design teams to consider fire safety from the very outset;
Gateway Two (pre-construction) requires detailed documentation (e.g. a Construction Control Plan, Fire and Emergency File, etc.) to prove compliance.
Preparing these documents and integrating safety systems early can add soft costs (engineering, consultancy fees) to a project.
Likewise, any delay at a gateway awaiting approval can extend the project timeline, indirectly raising costs (interest, preliminaries).
For RCAs, this translates into higher professional fees allowances – modern rebuild estimates must budget not just for bricks and mortar, but also for the extensive regulatory sign-off process (e.g. design rework contingencies, fees for fire engineers and approvals). The Gateway regime essentially means no shortcuts, which is excellent for safety but means a more expensive rebuild in compliance.

Green fire exit sign with left arrow and running figure on a ceiling in a brightly lit corridor. White ceiling tiles visible.

Stricter fire safety and structural standards: A host of specific regulations have been updated. To highlight a few:
- Approved Document B (Fire Safety) now mandates sprinkler systems in new residential buildings over 11m, and in all new care homes. It also has provisions about improved fire detection and alarm systems. Thus, a rebuild of a mid-rise block of flats that previously had no sprinklers would now include a full sprinkler installation (costing, say, £25–£35 per square meter across the building, which adds up).
- Second staircase requirement: As discussed, any tall residential tower planned now or in the near future will require two means of escape vertically. Incorporating a second stair not only incurs the direct cost of construction for that stairwell, but can also reduce the net saleable floor area (in a development scenario) – effectively it’s a cost with no revenue, which in an insurance scenario is purely an extra expense with no “old for new” equivalent. RCAs for buildings in the ~6+ storey range should check if a second stair would be mandated upon rebuild; if yes, the cost plan must include the added stair core and associated structural changes (potentially hundreds of thousands of pounds extra in a large tower). There is additional guidance for Care homes of 11m2 high with a communal area of 60sq m these buildings will require an additional staircase.
- Non-combustible materials: The ban on combustible external wall materials for high-rises (in force since Dec 2018) means features like cladding, insulation, balconies, and even spandrel panels must use Class A2-s1,d0 (limited combustibility) or better materials. For example, if an older high-rise had an ACM or HPL cladding facade (combustible), a like-for-like replacement would no longer be legal – the rebuild must use solid metal or mineral fibre panels, which are more expensive. Similarly, timber balconies or siding would be replaced with metal or other non-combustible alternatives. These substitutions can dramatically increase costs. (As a rough gauge, the cost to reclad with A2-rated materials can be 1.5x–2x the cost of the original combustible cladding). An RCA must factor this in, otherwise, the sum insured would be too low to cover a code-compliant rebuild.
- Structural robustness: The new regime also emphasises overall structural safety (partly learning from the 2018 Edinburgh schools wall collapse and others). Regulators may expect higher robustness in ties, fixings, and key structural elements. While harder to quantify, this can mean additional reinforcement or quality control in a rebuild.
- Fire fighting access and systems: High-risk buildings might need features like firefighting lifts, emergency power backup for alarms, or refuge spaces for disabled occupants (if redesigning under current standards). For instance, some jurisdictions are moving toward requiring evacuation lifts in tall buildings. Though the BSA guidance didn’t mandate it, it encourages provision. If a building is being fully rebuilt, adding an evacuation lift in a 30-storey tower would be a significant cost (the lift itself, the shaft, backup generators, etc.).

Construction worker in orange vest and hard hat places cladding on building wall. Ladder and bright sky in background.

Increased remediation and compliance costs: Even beyond construction, new laws have changed who pays for safety upgrades. Leaseholder protections in the BSA mean building owners (or original developers) shoulder more of the expense for fixing defects. Indirectly, this is causing building owners and insurers to be much more proactive in ensuring adequate cover. A building with potential defects might face remediation orders (the Act gave powers for landlords to be legally forced to fix unsafe cladding). If a loss event occurs and the building was already under such an order, the rebuild might be held to higher standards or combined with remediation scope. Brokers should be aware that these legal tools exist – for instance, the first government Remediation Order was issued in late 2023 to force a landlord to fix defective cladding. This climate means no one wants to take chances with underestimating costs. Better to insure for full compliance costs now than be caught short and potentially non-compliant later.

Overall, the “new normal” for high-rise and complex buildings is higher construction costs – estimates suggest that meeting post-Grenfell safety requirements can add anywhere from 5% up to 20% to construction budgets, depending on the building’s height and original spec. Brokers should treat older rebuild valuations with caution; a property insured for £10m five years ago might need £12m+ today to reflect the new safety-driven costs.

How RebuildCostASSESSMENT.com accounts for legislative changes (with examples)

Our team is fully aware of these evolving requirements and integrates them into the valuation process for rebuild costs. When conducting an RCA in today’s context, we take a proactive approach to embed the cost of compliance and even anticipate upcoming regulatory changes where prudent. Here’s how we incorporate the post-2022 legislative landscape into our assessments, with brief case examples:

Modern building regulations pricing: We maintain an internal database of construction cost rates that reflect current standards. For example, if assessing a high-rise apartment block, our cost model will automatically include the likely expense of sprinklers on every floor, two stairwell cores (if applicable), fire-rated doors and glazing, etc. We do not simply use the original build cost, index linking or outdated cost per m² figures from before these rules – we adjust for today’s specs. For instance, a 15-storey residential block built in 2010 might have had one stair and no sprinklers; our rebuild cost now would add, say, ~£150k for a second stair shaft and ~£100k for a sprinkler system throughout (rough illustrative numbers), plus any cladding replacement with A1/A2 materials. We also consider things like inflation in construction and shortages of qualified fire engineers (which can drive up fees). By staying current with industry data and guidance, we aim to ensure the sum insured truly covers a compliant rebuild.

Case study – Bouverie Court, Bristol: A stark example of how assumptions have changed is Bouverie Court, a housing development in Bristol completed in 2011. Post-Grenfell external wall surveys in 2021 uncovered numerous build quality and fire safety issues, so severe that the cost to remediate was estimated around £4 million, and the housing association determined it was not financially viable to repair the building. They are instead opting to demolish it entirely by 2026, displacing all residents. Before 2017, no one anticipated that a relatively new building would require such drastic and costly intervention. For rebuild cost assessments, the lesson from Bouverie Court is that hidden defects and new safety expectations can drastically increase costs. If we were tasked with valuing Bouverie Court for insurance in 2025, we would need to assume a rebuild that corrects all those deficiencies, effectively building it properly as per today’s code. That likely means our RCA would far exceed the original construction budget. This case underscores why relying on historical construction costs can be dangerous; only a fresh assessment capturing current requirements would provide adequate insurance coverage. (Bouverie Court’s plight also demonstrates why our surveyors refrain from commenting on cladding – that requires specialists, and indeed their fate was decided by detailed surveys and court cases, not generalists.) It’s an unfortunate situation that we hope other building owners can avoid by staying ahead of compliance via proper assessments.
Continuous training and updates: Our surveyors undergo continuous professional development to keep up with legislation like BSA 2022 and its secondary regulations. We regularly review government guidance and RICS advisories. For instance, when the official guidance on second staircases was published in March 2024, we immediately updated our internal checklist for buildings in the 18m+ category, flagging that any applicable building with one stair now needs a scenario analysis for adding a second in a rebuild. Similarly, we watch the progress of regulations on existing buildings (for example, a proposal that high-rises might require periodic facade inspections) because anything that suggests future capital expenditure might influence today’s rebuild valuation assumptions. Our goal is to be proactive rather than reactive. We don’t wait for a client to insist on including something; we strive to incorporate it by default if it’s a known requirement. This way, brokers and clients receive a valuation that is robust and forward-looking, not an unrealistically low figure that assumes a pre-Grenfell world.

By integrating these practices, RebuildCostASSESSMENT.com delivers reliable valuations amidst a changing regulatory landscape. For brokers, this means you can trust that the figures we provide already have those “Gateway” and safety compliance costs baked in. It helps you advise your clients with authority, using our report to explain why their sum insured might need to increase. For insurers, it means reduced risk of underinsurance on complex risks. And for building owners, it provides peace of mind that in the worst-case scenario of a total loss, the insurance payout would allow them to rebuild to all current legal standards, not just to the bygone standards (which would be insufficient and unlawful today).

Example – adjusting cost assumptions

Hand pressing calculator buttons, pen in hand, on a desk with financial charts. Symbolising building construction cost calculations. Laptop in background, office setting.

To put it in perspective, consider a hypothetical 20-storey apartment block built in 2015 with an ACM cladding facade (the type implicated at Grenfell). Back then, the rebuild cost might have been calculated at ~£2,000 per m². Post-2022, if we do an RCA for the same building: we know a second stair is now required (if the building only had one), which adds structural reconfiguration – say another £100/m² spread across the building. Sprinklers were not present, now they must be – add £50/m². Plus general inflation and contingency for stricter oversight, perhaps another £150/m². Suddenly the new rebuild rate might be ~£2,500 per m². On a large building, that’s millions of pounds difference. Our process will capture those differences. As another concrete example, a mid-rise block from 2005 with no lift and minimal fire features: if it’s 6 storeys (~18m) it now likely needs sprinklers by current code, so we’d include the ~£75k cost for that in the valuation; if it’s 7 storeys (making it an HRB), then in addition to sprinklers, we factor in the cost of engaging the Building Safety Regulator, creating the digital golden thread of building information, etc., as part of professional fees – perhaps an extra 1% of build cost. These adjustments ensure coverage aligns with reality.

We are currently taking 10-12 working days on average to complete reports.
As these are subject to change, please check back for updates.