Tower Hamlets has one of the highest concentrations of high-rise residential buildings in London, particularly in the Canary Wharf, Isle of Dogs and Poplar areas. Many of these buildings were constructed between 2000 and 2020 and feature external wall systems that include aluminium composite material (ACM) panels, high-pressure laminate (HPL), rendered insulation systems and other materials that are now subject to scrutiny following the Grenfell Tower tragedy. For flat owners in these buildings, the EWS1 (External Wall System) form has become a critical document for mortgage lending and property transactions.
The EWS1 form was introduced by the Royal Institution of Chartered Surveyors (RICS), UK Finance and the Building Societies Association as a standardised way for mortgage lenders to assess the fire risk associated with a building's external wall system. The form is completed by a qualified assessor — typically a chartered surveyor or fire engineer with the appropriate competency — following an assessment of the building's external walls, including cladding, insulation, balconies and any attachments.
The assessment results in one of four ratings: A1 (no combustible materials, no concerns), A2 or A3 (combustible materials present but risk is low or acceptable without remediation), B1 (combustible materials present, remediation of limited scope needed) or B2 (combustible materials present, significant remediation required). For most lenders, an A rating or B1 rating allows mortgage lending to proceed, while a B2 rating effectively prevents lending until remediation is complete.
Tower Hamlets is disproportionately affected by the cladding and fire safety crisis. The borough contains a large number of buildings over 18 metres in height (the threshold above which the Building Safety Act 2022 imposes the most stringent requirements), many of which were built during the rapid development of Docklands and the surrounding areas. The volume of buildings requiring assessment has created a significant backlog, with many flat owners unable to sell, remortgage or even obtain adequate insurance.
We provide EWS1 assessment services across Tower Hamlets and have detailed experience of the building types and external wall systems commonly found in the borough.
Many Tower Hamlets high-rises feature multiple cladding types on a single building — a combination of rendered insulation, curtain walling, rain screen panels and balcony systems. Assessing these buildings requires detailed investigation, often including intrusive inspections to determine what lies behind the visible cladding. The complexity increases the time and cost of the EWS1 assessment and the potential scope of any remediation.
Inspecting the external walls of a 20- or 30-storey building presents significant access challenges. Rope access, mobile elevated work platforms (MEWPs) or cradle systems may be needed to carry out intrusive inspections at height. Access arrangements must be coordinated with the building manager, and traffic management may be required for plant access. These logistics add to the assessment cost and timeline.
Tower Hamlets' large residential developments often have complex ownership structures involving freeholders, management companies, right-to-manage companies, housing associations and individual leaseholders. Coordinating an EWS1 assessment requires engagement with all relevant parties, agreement on funding and a clear decision-making process. In practice, this stakeholder complexity is one of the main causes of delay in the borough.
Buildings awaiting remediation often require interim fire safety measures, which may include a waking watch, upgraded alarm systems, fire risk assessment reviews and enhanced management procedures. These measures carry ongoing costs that are typically recovered through the service charge. Understanding the relationship between the EWS1 assessment, interim measures and the remediation programme is essential for flat owners and managing agents.
A B2 rating means that the assessor has identified combustible materials in the external wall system that require remediation to bring the building to an acceptable fire safety standard. This does not necessarily mean the building is immediately dangerous — but it does mean that the current external wall construction does not meet the standard that lenders and insurers require. For flat owners, the practical impact is severe: most mortgage lenders will not lend against a property with a B2 rating, making it extremely difficult to sell or remortgage.
Once a B2 rating is issued, the building owner or responsible entity should commission a full Fire Risk Appraisal of External Walls (FRAEW) in accordance with PAS 9980:2022. This provides a more detailed, risk-based assessment that identifies the specific deficiencies and sets out a proportionate remediation scope. The FRAEW may in some cases conclude that the risk is lower than suggested by the EWS1 B2 rating, potentially reducing the scope of remediation required.
Following the FRAEW, a remediation specification is developed, contractors are procured, and the remediation works are carried out. Once complete, a new EWS1 assessment is carried out. If the building now meets the required standard, an A or B1 rating is issued, allowing mortgage lending to resume. The entire process from B2 rating to completion of remediation can take 18 months to three years or more, depending on the scale and complexity of the works and the availability of funding.
For qualifying buildings in Tower Hamlets, government funding may be available through the Cladding Safety Scheme (CSS) or the Building Safety Fund (BSF). Buildings over 18 metres with unsafe cladding are eligible for the CSS, which covers the cost of assessment and remediation. The Building Safety Act 2022 also provides leaseholder protections, capping the amount that qualifying leaseholders can be asked to contribute towards remediation costs. Navigating the funding landscape requires specialist advice and early engagement with the relevant schemes.
A B2 rating means that combustible cladding or other fire safety deficiencies have been identified in the external wall system and remediation is required. Most lenders will not offer a mortgage on the property until remediation is complete and a new EWS1 form is issued with an A or B1 rating. A B2 rating does not mean the building is immediately dangerous, but it does mean the external wall system does not meet current fire safety standards required by lenders and insurers.
It depends on the building height. Since January 2023, EWS1 forms should not be required for buildings below 11 metres. For buildings between 11 and 18 metres, lender requirements vary. For buildings over 18 metres (approximately six storeys), most lenders still require an EWS1 form or evidence that the building has been assessed under PAS 9980. In Tower Hamlets, where many residential buildings are high-rise, an EWS1 form is frequently needed for a sale to proceed.
The cost of the EWS1 assessment is typically borne by the building owner or freeholder, not individual leaseholders. Where the building is managed by a residents' management company, the cost will usually be shared through the service charge. For buildings that qualify for government funding through the Building Safety Fund or Cladding Safety Scheme, the cost of assessment and remediation may be covered. Leaseholders in buildings over 11 metres should not be required to pay more than prescribed caps under the Building Safety Act 2022.
Timescales vary depending on the complexity of the building and the availability of qualified assessors. A straightforward assessment for a building with a simple cladding system may take four to eight weeks from instruction to certificate. Complex high-rise buildings with multiple cladding types may take considerably longer. The shortage of RICS-qualified fire safety assessors means that lead times for initial assessment can be several weeks. We recommend engaging early to avoid delays.
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