Fact 33. Retaining Walls - how do they matter to sellers and buyers

Retaining walls affect property value, legal responsibility, and sale outcomes for both sellers and buyers—understand key risks and benefits for smoother conveyancing transactions.

There are significant consequences for sellers and buyers in property transactions, influencing legal liability, property value, and future maintenance costs. Here is an in-depth, copy-ready guide on why retaining walls matter and what to look out for during conveyancing.

Retaining walls are structures built to hold back earth, commonly found on sloping sites, garden terraces, and properties where different ground levels meet. While they might seem like simple boundary features, their legal and practical implications can affect everything from liability to sale price and future disputes. Understanding retaining walls is essential for buyers and sellers if they want to avoid costly surprises and legal issues down the line.

What is a Retaining Wall?

A retaining wall is a structure designed to hold back or support earth at different levels, stabilizing land and preventing soil movement and erosion. They are usually made of concrete, stone, brick, or timber. Retaining walls are used to create flat, usable spaces on sloped land, separate properties of different levels, prevent landslides, and support roads or paths. Their presence and condition can dramatically affect a property's safety, usability, and market value.

Why Retaining Walls Matter for Sellers

For sellers, the presence, condition, and compliance of retaining walls can have a big impact on a property sale. Here’s why:

- Valuation and Marketability: Major defects, signs of instability, or lack of planning permission for retaining walls can reduce a property’s value. Building inspectors often flag poorly maintained or structurally unsound retaining walls, which can lead to buyers asking for significant price reductions or dropping out of the sale.

- Liability: Sellers must clarify who holds responsibility for maintaining and repairing retaining walls. If a wall is deteriorating or fails during ownership, the seller could be liable for damages to neighboring properties or public spaces.

- Legal Compliance: Walls above a certain height or near public roads may need planning permission. Selling a property with non-compliant retaining walls can lead to delays or legal disputes – and in some cases, enforcement or demolition orders from local authorities.

- Disclosure Obligations: Sellers must disclose defects, boundary disputes, or ambiguities regarding retaining walls in official paperwork known as “important matters statements.” Failing to do so can create grounds for buyer claims after completion.

Why Retaining Walls Matter for Buyers

Buyers need to pay careful attention to retaining walls before committing to a purchase:

- Safety and Structural Risks: Retaining walls failing due to age, poor build quality, or lack of maintenance can cause expensive damage, landslides, and even endanger buildings on the property. Engineers and inspectors look closely at walls’ condition, stability, and compliance during pre-purchase surveys.

- Maintenance Responsibilities: Buyers need clear information on who maintains the retaining wall – sometimes responsibility falls to the party whose land is supported by the wall, others may be shared or the developer. Unclear boundaries or ambiguous deeds can lead to disputes and unexpected costs.

- Mortgage and Insurance: Some lenders and insurers will not proceed with properties with defective, non-compliant, or ambiguous retaining walls. Buyers should ensure survey reports and legal checks address retaining wall issues fully.

- Planning Restrictions: High retaining walls or those near public areas may require planning permission. Buyers must check that the wall’s construction and current use meet regulations, otherwise the local authority may issue notices demanding costly remedial work or removal.

Key Facts About Retaining Walls in Conveyancing

1. Ownership and Responsibility

- The person whose land is physically supported by the retaining wall is usually responsible for its repair and maintenance.

- If a retaining wall runs along a boundary, it may be a “party structure,” with shared repair duties, but the law presumes responsibility falls to the owner benefiting from the support.

- Title deeds, Land Register, and surveys should show retaining wall locations and specify maintenance responsibilities. If unclear, buyers and sellers must clarify via negotiation or surveyors before completing a sale.

2. Legal Compliance

- The Highways Act 1980 and local building regulations govern retaining wall safety, position, and permissions. Walls over 1 metre high near streets, or over 2 metres elsewhere, often require planning permission and compliance checks.

- Unapproved or unsafe walls can result in fines, enforcement notices, and demolition orders. Retrospective planning permission is possible but not guaranteed.

3. Sale and Mortgage Impact

- Surveyors will highlight any retaining wall defects on inspection reports. Major issues can cause buyers or lenders to pull out, or negotiate steep price reductions.

- Walls that are not up to standard affect the property’s insurability, collateral value, and loan eligibility.

- Properties near public roads with retaining walls may be subject to council or highways authority maintenance rules. Buyers should check local status before purchasing.

4. Disputes and Repairs

- Disputes over wall ownership, maintenance payments, or responsibility can escalate, especially if boundaries are ambiguous in the deeds.

- Sections 2 and 11 of the Party Wall Act 1996 may apply to shared retaining walls, with rights and duties for repair, cost contribution, and notice requirements. Surveyors can mediate disputes and clarify liabilities.

Practical Checklist for Sellers and Buyers

Before buying or selling a property with a retaining wall, use this checklist to avoid surprises:

- Review the title deeds and Land Register for boundary and retaining wall notes; clarify responsibility for maintenance and repair.

- Get a professional survey of the retaining wall: check for structural soundness, drainage, and compliance with planning regulations.

- Confirm the wall’s height and proximity to public highways or boundaries to establish planning permission requirements.

- For buyers, request copies of previous repair invoices, planning consents, and structural surveys; if unavailable, commission new ones.

- For sellers, proactively disclose known issues, disputes, or peculiarities regarding retaining walls in the formal sale documents.

- Address defects, instability, or compliance issues before going to market to protect against delays, renegotiation, or failed sales.

- Negotiate any shared responsibility or party wall status formally, referencing the Party Wall Act and seeking professional mediation if needed.

- Ensure all communications regarding responsibility, cost-sharing, or repairs are documented and stored.

Common Problems with Retaining Walls

- Cracking or movement: Due to poor materials, age, inadequate drainage.

- Water damage: Often caused by poor drainage, leading to saturation, subsidence, or wall collapse.

- Boundary disputes: Arise when ownership and maintenance duties are unclear.

- Planning and compliance breaches: Occur with walls built outside permission or against conservation area policies.

- Insurance and repair limits: Some insurers restrict cover or increase premiums for properties with large or defective retaining walls.

The Law on Retaining Walls

UK law contains specific rules on retaining walls near highways and on higher ground:

- Walls within 4 yards (3.66 metres) of a street and more than 4 foot 6 inches high must comply with Highways Act rules and often need local authority consent.

- Retaining walls on boundary lines may involve the Party Wall Act 1996, requiring the parties to give notice before repairs and allocate costs by benefit derived from the supporting structure.

- Breaching planning rules can result in fines and the requirement to rebuild or remove offending walls – even years after construction.

Who Maintains Retaining Walls?

- If the wall supports your land, you are generally responsible for it.

- Shared walls may mean equal responsibility and joint expense.

- Walls supporting public highways are usually council responsibility, except those built for private benefit.

- Where records are silent, case law, surveys, and party wall notices determine responsibility.

What Happens if a Retaining Wall Fails?

If a retaining wall collapses, you must rebuild it and repair any resulting damage to land or structures. If adjoining land is damaged, the responsible party may face claims for damages. Insurance can help, but policies may have exclusions for poor maintenance or unapproved structures. Prompt action and professional assessment are essential.

Retaining Walls and Property Value

Well-built, legally compliant retaining walls add functional space, safety, and value to a property. Poorly maintained walls and disputes can reduce marketability, limit buyers, and lead to lower prices or failed sales. Regular inspections and strong records protect sellers’ value and buyers’ peace of mind.

Final Practical Advice

For sellers:

- Identify, repair, and document retaining wall issues before sale.

- Be transparent with buyers about wall location, responsibility, and any historic disputes.

For buyers:

- Instruct your surveyor to inspect retaining walls thoroughly, checking for structural defects and legal compliance.

- Clarify responsibility for future repairs and negotiate for wall condition or repair costs if defects are found.

Retaining walls are more than boundary features: they represent liability, value, safety, and ongoing maintenance. Proper legal and physical checks at every stage protect both parties from unpleasant surprises and give confidence in the transaction process.