Cladding and Building Safety What UK Home Buyers Must Check Before Offering

On fourteenth June 2017, seventy-two people died in the Grenfell Tower fire in west London. The investigation that followed exposed something deeply uncomfortable: thousands of residential blocks across the UK had been clad in materials that could help a fire spread fast up the outside of a building. Grenfell wasn't a one-off tragedy caused by a single rogue developer. It was a symptom of decades of loose regulation, poor oversight, and a culture in which fire safety checks were not taken seriously enough.

For flat buyers, the fallout was immediate and lasting. Mortgage lenders started refusing to lend on flats in blocks where the external wall materials hadn't been properly assessed. Valuers started down-valuing or simply declining to value them. Overnight, people who'd done nothing wrong found themselves owning a flat they couldn't sell, couldn't remortgage, and couldn't get insurance on at a sensible price.

If you're buying a flat now, especially in a block built or refurbished between roughly the nineteen eighties and two thousand and fifteen, you need to understand this landscape before you fall in love with a place and make an offer.

Parliament passed the Building Safety Act in April 2022. It's the most significant piece of legislation affecting residential buildings in a generation, and it created a proper framework for who is responsible for making buildings safe and who picks up the bill.

The headline point for buyers is this: developers and building owners, not leaseholders, are now legally responsible for fixing historical fire safety defects in buildings they built or refurbished. The government set up a Developer Remediation Contract, and the biggest housebuilders signed up, committing to fund repairs to buildings they were responsible for. A separate Building Safety Fund exists for buildings where the original developer has gone bust or can't be traced.

The Act also introduced the concept of a Responsible Person, someone who must register higher-risk buildings with the Building Safety Regulator and demonstrate ongoing compliance. Higher-risk buildings are defined as those at least eighteen metres tall, or at least seven storeys, with at least two residential units.

For you as a buyer, the practical upshot is that if you're looking at a flat in a qualifying building, you have more legal protection than buyers did five years ago. But that doesn't mean the process is smooth. Remediation can take years, and during that time selling or mortgaging the flat can still be tricky.

EWS stands for External Wall System. The EWS1 form was introduced by UK Finance and the Royal Institution of Chartered Surveyors in December 2019 as a way for lenders and valuers to get consistent, reliable information about the fire risk posed by a block's external walls.

The form is completed by a qualified professional, typically a fire engineer or a chartered surveyor with specific competence in fire risk assessment. It's not a full building survey. It's specifically focused on the external wall construction, including cladding panels, insulation, balconies, and any other materials on the outside of the building that could contribute to fire spread.

The form gives one of two outcomes. An A rating means the external wall materials are unlikely to support combustion, or that any combustible materials present are of a limited extent. A B rating means there are combustible materials present and a fire risk assessment of the external wall has been carried out. Within those two categories there are further subdivisions. An A1 or A2 rating generally means lenders are comfortable. A B1 rating means the risk has been assessed and no remediation is needed. A B2 rating is the one that causes problems, because it means the assessor has concluded that remediation is needed before the building is safe.

Here's the important nuance. An EWS1 form is not a legal requirement. It's an industry standard document. But in practice, if a lender's valuer wants to see one and it doesn't exist or shows a B2, you will struggle to get a mortgage on that flat. So for practical purposes, it matters enormously.

This is where things get genuinely confusing, and where a lot of buyers waste time and money. RICS updated its guidance in 2021 to clarify that not every block needs an EWS1 form.

Blocks of fewer than five storeys with no cladding and no balconies with combustible materials generally don't need one. The form is most relevant for taller blocks, blocks with identifiable cladding systems, and blocks where the external wall construction is unclear or complex. That said, individual lenders set their own policies, and some are more cautious than others. Your mortgage broker should know which lenders are most relaxed about which building types.

If you're buying in a block that already has an EWS1 form, check the date. Forms are generally considered valid for five years, but if remediation work has been done since the form was issued, a new one may be needed. If the block is mid-remediation, the picture is more complicated still, and you need a solicitor who knows this area well.

Don't assume a new-build is automatically fine, either. Some new-build blocks completed in the early two thousands used cladding systems that are now considered problematic. Always ask.

Right, here's the practical bit. Do these things before you get emotionally attached and before you spend money on surveys and legal fees.

1. Ask the estate agent directly whether an EWS1 form exists and what rating it carries. If they don't know, that's a red flag about how prepared the seller is for the sale.

2. Ask what height the building is and how many storeys it has. This tells you whether it falls under the higher-risk building regime.

3. Find out who the freeholder or building owner is and whether they've registered the building with the Building Safety Regulator if it qualifies.

4. Ask whether the building is on the Developer Remediation Contract list or has an application to the Building Safety Fund. The government publishes information on both schemes.

5. Check whether there's an active remediation programme underway. If so, ask for a timeline and who is funding it. Leaseholders in qualifying buildings should not be paying for historical fire safety defects.

6. Talk to your mortgage broker before you offer, not after. Tell them the address, the height of the block, and whether an EWS1 exists. They can tell you quickly whether your chosen lender will be comfortable.

7. Instruct a solicitor who has experience with leasehold and building safety matters. This is not the moment to use whoever is cheapest on a comparison website.

Finding out a block has a cladding issue doesn't automatically mean you should walk away. It depends on the nature of the problem, the remediation plan, and your own appetite for complexity.

If there's a clear remediation plan funded by the developer or the Building Safety Fund, with a realistic timeline and no costs falling on leaseholders, some buyers do proceed. The flat may be priced to reflect the uncertainty, which could mean you get a better deal. But you need to go in with eyes wide open about the risk that timelines slip, that selling again before remediation completes will be hard, and that some lenders still won't touch the building even with a plan in place.

If there's no plan, no EWS1, and no clarity on who's paying, that's a much harder situation. You'd be taking on significant uncertainty, and the legal protections, while real, can take time to enforce.

Always get specialist legal advice. The leasehold advisory service, known as LEASE, offers free guidance and is a good starting point. The End Our Cladding Scandal campaign also has useful resources for buyers trying to understand their position.

Here's the thing nobody says clearly enough. Buying a flat in a block that has cladding issues is not impossible, but it's genuinely more complicated than it was before Grenfell, and it should be. The legal framework is better than it was. Leaseholder protections are stronger. But the system is still catching up with the scale of the problem, and that means delays, uncertainty, and the occasional situation where a flat is simply unsellable until remediation is complete.

The best thing you can do is go in informed. Ask the hard questions early. Use professionals who know this area. And don't let anyone rush you into an offer before you understand what you're buying.

A flat in a well-managed, properly assessed block is still a perfectly good purchase. Just make sure you know which kind you're looking at.