Murton & Co were instructed to assist homeowners seeking a Regularisation Certificate for a 1930s property that had undergone significant alterations over its lifetime.

The property had originally been converted into flats before later being reinstated as a single dwelling. However, the reinstatement works had been carried out without Building Regulations approval, creating a compliance issue that came to light during the conveyancing process.

With an agreed sale already in place, the homeowners faced the prospect of delays, additional costs, and uncertainty at a critical stage of the transaction.

Our role was to provide a robust technical assessment that would satisfy Building Control requirements while ensuring any recommendations remained proportionate, evidence-based and commercially sensible.

The Challenge

When retrospective approval is sought through the Regularisation process, Building Control must be satisfied that the property meets the relevant requirements of the Building Regulations.

In this case, particular attention focused on Part L (Conservation of Fuel and Power) and whether thermal upgrades would be required before approval could be granted.

The homeowners were concerned that Building Control might insist on costly energy efficiency improvements, including cavity wall insulation and other thermal enhancement measures.

Any requirement for substantial works would not only incur costs but could also jeopardise the planned property sale.

The challenge was therefore to establish whether further thermal upgrades would provide a meaningful improvement in performance and whether they could be justified under the guidance contained within Approved Document L.

Our Approach

Murton & Co adopted a structured, evidence-led approach to assess the property’s thermal performance and compliance position.

The assessment included:

Comparative SAP Energy Modelling

We undertook comparative SAP calculations to evaluate the likely impact of proposed thermal improvements on the overall energy performance of the property.

In-Situ U-Value Testing

Rather than relying solely on assumed construction values, we carried out in-situ U-value testing of the external walls to establish actual thermal performance.

This provided a more accurate understanding of the building’s condition and enabled informed decision-making.

Cost Benefit Assessment

The potential improvements were assessed against the guidance contained within Approved Document L, considering both performance gains and financial implications.

15 Year Payback Analysis

A detailed assessment was undertaken to determine whether proposed measures satisfied the recognised 15-year payback test, a key consideration when evaluating the reasonableness of thermal upgrades.

Findings

Our analysis demonstrated that the proposed thermal improvements would result in only modest gains, namely  an overall energy performance improvement of approximately 6–7%, translating to estimated annual savings of just £73.65. Similarly, the cost of installation significantly exceeded the value of the projected energy, making the works difficult to justify on either technical or economic grounds.

The evidence clearly demonstrated that the proposed upgrades would impose a disproportionate financial burden while delivering limited practical benefit.

The Outcome

Following submission of the technical evidence and supporting analysis, Building Control accepted Murton & Co’s findings and agreed that no thermal upgrades were required.

This delivered several important benefits for the homeowners:

• Avoided approximately £2,500 of unnecessary remedial works.
• Prevented delays to an agreed house sale.
• Reduced stress and uncertainty during the conveyancing process.
• Enabled funds to be directed towards the clients’ next property purchase.
• Achieved compliance through a proportionate and evidence-based approach.

Most importantly, the clients were able to proceed with confidence, knowing that the regulatory requirements had been satisfied without incurring unnecessary expenditure.

The customer, Dylan said:

“We recently used Murton & Co. for work that was requested by the council around an SAP report and we couldn’t be happier with the service we received. Jonny and Caroline were extremely friendly, professional and helpful throughout the entire process.

They made everything straightforward and stress-free, keeping us informed every step of the way. I would strongly recommend Murton & Co. to anyone looking for a reliable and customer focused company.”

Why This Matters

Building Regulations compliance is often perceived as a process that automatically requires additional works or costly upgrades. However, regulations and guidance are intended to be applied reasonably and proportionately.

This project demonstrates the value of combining technical expertise with practical judgement.

By undertaking detailed analysis, gathering site specific evidence and presenting a clear technical case, Murton & Co was able to help Building Control reach an informed decision that balanced compliance requirements with the realities faced by the homeowners.

The result was a solution that protected the clients’ interests while maintaining regulatory integrity.

How Murton & Co Can Help

Whether dealing with retrospective approvals, Regularisation Certificates, SAP assessments, thermal performance investigations or Building Regulations compliance issues, Murton & Co provides clear, practical and commercially focused advice.

Our objective is always to identify the most appropriate route to compliance, ensuring clients meet regulatory requirements without unnecessary cost, disruption or delay.

To discuss a similar project, contact Murton & Co today.