Buying a Property

Survey Red Flags, What RICS Surveyors Flag and What to Do Next

A property survey can uncover serious issues that change the course of a purchase. This guide explains the most common red flags RICS surveyors raise, what they mean in practice, and how to respond.

Published: 16 Mar 2026 · Updated: 16 Mar 2026 · 7 min read

#HouseBuying#UKProperty#PropertySurvey#SurveyRedFlags#RICS#PropertyPassportUK

Understanding Survey Condition Ratings

RICS surveyors use a standardised condition rating system in their reports. Understanding what each rating means is essential to interpreting a survey correctly.

Rating	Description	What it means in practice
Condition 1	No repair is currently needed	Nothing to action
Condition 2	Defects that need repairing or replacing but are not considered urgent	Monitor and budget for future repair
Condition 3	Defects that are serious and/or need to be repaired, replaced or investigated urgently	Obtain specialist reports and/or negotiate on price

A survey containing several Condition 3 ratings does not automatically mean you should walk away. It means you need more information before proceeding, specifically, specialist reports that quantify the cost of remediation.

The Most Common Survey Red Flags

Damp

Damp is one of the most frequently flagged issues in residential property surveys. Surveyors distinguish between penetrating damp (water entering through the fabric of the building), rising damp (ground moisture moving up through walls), and condensation (internally generated moisture).

The cause matters significantly. Condensation is often resolved through improved ventilation and is relatively low cost. Penetrating damp caused by defective pointing or failed render may require moderate external repairs. Rising damp, though frequently diagnosed, is contested among specialists, and a second opinion from an independent damp specialist (not one recommended by a remediation company) is often worthwhile before committing to expensive treatment.

Roof Condition

A surveyor will visually inspect the roof covering, chimney stacks, flashings, and guttering. Common flags include missing or slipped slates or tiles, failed lead flashings, defective pointing to chimney stacks, and blocked or failing gutters. Full roof replacement is a significant cost; targeted repairs are more manageable. Always obtain a specialist roofer's quote.

Structural Movement

Signs of structural movement, cracking, distortion of door frames, uneven floors, are among the most serious flags a surveyor can raise. Not all movement is active; many Victorian and Edwardian properties show evidence of historical settlement that has long since stabilised. Your surveyor will note whether movement appears recent or historic, and whether further specialist investigation is recommended.

Where subsidence is suspected, a structural engineer's report will be required. This is distinct from a building survey, a structural engineer assesses the cause and extent of movement and recommends a remediation strategy. Mortgage lenders will require this before issuing a formal offer on an affected property.

Electrical and Heating Systems

Most survey levels will note if the electrical installation or boiler is beyond its expected service life, or if fuse boards are outdated (older consumer units without RCDs, for example). These items carry a Condition 2 or 3 rating depending on severity, and their presence does not make a property unmortgageable, but you should obtain quotes for upgrading before exchange.

Japanese Knotweed

Surveyors are required to flag any visible signs of Japanese knotweed, an invasive plant species that can cause structural damage and significantly affects mortgageability. If flagged, specialist treatment plans, which can take several years, will be required. Many lenders will not lend on affected properties without a management plan in place from an accredited specialist.

What to Do After a Bad Survey

**Step 1: Do not panic.** A survey flagging multiple issues is normal for older properties. The question is not whether issues exist but how much they cost to resolve.

**Step 2: Obtain specialist reports.** For any Condition 3 item, commission an independent specialist report. For structural issues, use a RICS-accredited structural engineer. For damp, use a PCA-qualified surveyor who has no commercial interest in selling you treatment.

**Step 3: Get contractor quotes.** Actual remediation quotes are more useful than any estimate in the survey report. Two or three independent quotes give you a realistic cost range.

**Step 4: Renegotiate or withdraw.** Once you have hard costings, you can approach the seller to renegotiate the price, ask them to carry out the works before exchange, or withdraw if the figures do not stack up.

Using Property Passport UK Before You Survey

Before you commission any survey, check the property on Property Passport UK. The EPC rating and historical data can indicate how well-maintained the property has been. If the EPC shows a very low rating and the property has not been updated in many years, factor the likelihood of significant defects into your decision to survey at all, particularly for a more expensive level of report.