New Build EPC A Rating and Heat Pumps: What Buyers and Developers Really Need to Know in 2026

New Build EPC A Rating and Heat Pumps: What Buyers and Developers Really Need to Know in 2026

Last updated: 5 July 2026

Some new-build buyers are opening their first energy bills and finding quarterly costs of £600 or more — despite being handed the keys to a brand-new, supposedly energy-efficient home with an EPC A rating. That figure shocks people. It shocks them because EPC A is supposed to be the best possible rating, and yet the heat pump sitting in the utility cupboard is running far less efficiently than the developer's glossy brochure implied. Understanding why that gap exists — and what you can actually do about it — is what this article is about.

EPC A in a New Build: What It Actually Means (and What It Doesn't)

An EPC A rating tells you that, on paper, a property scores between 92 and 100 on the Standard Assessment Procedure (SAP) energy efficiency scale. New builds almost universally hit this threshold, largely because the SAP methodology rewards the combination of high insulation standards, double or triple glazing, and low-carbon heating — of which heat pumps are the primary example.

But here is the critical distinction: EPC A describes the theoretical performance of the building fabric and heating system based on a standardised set of assumptions. It does not measure how your household actually uses energy, whether the heat pump has been correctly commissioned, or whether the hot water cylinder is sized appropriately for your family. The rating is a model output. Your energy bills are real-world outputs. They are not the same thing.

This distinction matters enormously when evaluating developer-installed systems, and it is the first thing any new-build buyer with a heat pump should understand before they call their energy supplier and complain about costs.

The Future Homes Standard and Why 2026 Is a Turning Point

The Future Homes Standard heat pump requirement in the UK, expected to take full effect in 2026, mandates that newly built homes produce 75–80% fewer carbon emissions than those built under pre-2021 regulations. In practical terms, this almost certainly means gas boilers will no longer be permissible as primary heating systems in new builds. Heat pumps — primarily air source, occasionally ground source — will be the default solution for the vast majority of developers.

This is not a distant policy ambition. Developers building homes for occupation from 2026 onwards are already designing and procuring heating systems accordingly. If you are purchasing a new-build property now or planning to do so in the next twelve months, there is a very high probability your home will come with a heat pump pre-installed, whether you specifically requested one or not.

The policy shift also has implications for buyers of homes where the heat pump has been installed under older building regulations. Those homes may still qualify for the £7,500 Boiler Upgrade Scheme grant — but only if the heat pump installation itself was carried out by an MCS-certified installer. The BUS grant is not automatic simply because a heat pump is present; the installation documentation and the installer's MCS certification status are what make the difference. You can check your eligibility and understand the full process via our Boiler Upgrade Scheme guide.

New Build vs Retrofit: The Differences That Actually Matter

The heat pump new build vs retrofit difference in the UK context is significant, and it is often underestimated by buyers who assume a newer installation is inherently a better one.

In a retrofit, an installer typically conducts a heat loss calculation, specifies the correct heat pump output (in kilowatts), ensures the radiators are oversized if needed, and commissions the system with the household's specific pattern of occupancy in mind. There is a direct relationship between the installer and the end user.

In a new build, the developer procures heating systems at scale. The heat pump model may be chosen partly on cost and partly on compatibility with the plot type, not specifically on the thermal requirements of that individual unit. Commissioning may happen weeks before handover, often without the future occupant present. Settings like flow temperatures, hot water scheduling, and weather compensation curves are sometimes left at factory defaults — which are rarely optimal for UK climate conditions.

This creates a class of new-build heat pump problems in the UK that are surprisingly common: systems running at higher flow temperatures than necessary (reducing efficiency and CoP), hot water cylinders that run defrost cycles at inconvenient times, and occupants who have received minimal instruction on how their heating controls actually work.

Common new-build heat pump issues to watch for

• Flow temperatures set above 45°C when 35–40°C would be sufficient for the insulation levels present
• Hot water set points unnecessarily high, triggering frequent immersion heater top-up cycles
• Weather compensation not enabled or incorrectly calibrated
• No room-by-room heat loss calculation evidenced in the handover documentation
• Smart controls not configured for occupancy patterns

Developer Responsibility: Warranties, MCS, and What You're Owed

A developer-installed heat pump review in UK new builds consistently highlights the same concern: buyers often do not know what they are entitled to receive, and developers do not always volunteer the information proactively.

The heat pump warranty in a new build UK context involves at least two separate obligations. First, the manufacturer's warranty — typically five to ten years depending on brand, and usually conditional on annual servicing by a qualified engineer. Second, the developer's own liability under the Consumer Code for Home Builders or similar framework, which covers defects in workmanship and installation.

MCS certification is central to both. MCS (Microgeneration Certification Scheme) is the quality standard for heat pump installations in the UK. An MCS-certified installation comes with a certificate that confirms the system was designed and installed to an agreed technical standard. Without this, the manufacturer's warranty may be void, the BUS grant is inaccessible, and you have significantly fewer protections if the system underperforms. Ask your developer explicitly for the MCS installation certificate at the point of legal completion — not afterwards.

Annual servicing protects your warranty and efficiency, and it is something many new-build buyers overlook precisely because their home feels too new to need maintenance. The heat pump manufacturer's warranty terms are usually unambiguous on this point: a missed annual service can invalidate the warranty entirely.

Running Costs and Efficiency: The Numbers New-Build Buyers Should Know

The table above illustrates something the headline EPC A rating does not: the range of real-world outcomes is substantial, and it hinges almost entirely on whether the system has been correctly set up and maintained. A well-run heat pump in a new build can comfortably beat a gas boiler on running cost. A poorly commissioned one will not, and the difference is not the technology — it is the implementation.

For context, the UK electricity standing rate is approximately 24.5p/kWh under the current Ofgem price cap, with gas at approximately 6.99p/kWh. These figures are reviewed quarterly, but the underlying efficiency advantage of a high-CoP heat pump in a well-insulated new build remains consistent.

What New-Build Buyers Should Demand at Handover

This is where the honest answer to a frequently asked question belongs. The honest answer is that most new-build buyers accept their heat pump handover pack without reading it, and most developers know this. The result is that commissioning issues go unidentified for months, efficiency suffers, and by the time anyone investigates, the paper trail is thin.

At handover, you should request and retain the following:

• The MCS installation certificate (with the installer's MCS number)
• The heat loss calculation for your specific plot
• The manufacturer's commissioning report, signed and dated
• A written record of the flow temperature settings applied at commissioning
• The manufacturer's warranty documentation, including the annual servicing requirement
• Contact details for the appointed service engineer (not just a general developer helpline)

If the developer cannot produce these documents, that is a significant red flag. A £7,500 BUS grant, a manufacturer's warranty worth several thousand pounds, and years of running costs all hinge on this documentation being in order.

You can explore the full range of air source heat pump models commonly specified in new builds to understand whether your developer has chosen a well-regarded system or a budget unit — it makes a substantial difference to long-term reliability.

What Developers Need to Understand About Buyer Expectations in 2026

For developers reading this: the Future Homes Standard is not simply a compliance exercise. Buyers are increasingly sophisticated about heat pump performance, and word travels fast when a development earns a reputation for high energy bills or poor commissioning. The reputational risk of a poorly specified or poorly handed-over heat pump system is real and growing.

The developers who will fare best are those who treat heat pump commissioning as part of the customer experience rather than a technical afterthought. That means appointing MCS-certified installers (not just the cheapest subcontractor), conducting proper heat loss calculations per plot, providing occupant training at handover, and ensuring the first annual service is either included in the purchase or clearly communicated as the buyer's responsibility.

It also means engaging seriously with the BUS grant process where applicable. For buyers purchasing homes that qualify, the £7,500 available through the Boiler Upgrade Scheme can offset a meaningful portion of the system cost — but only with clean MCS documentation.

Frequently Asked Questions

My new build has an EPC A rating but my energy bills are high — can the heat pump settings be adjusted?

Yes, almost certainly. In the majority of cases, high running costs in new builds with heat pumps trace back to flow temperatures set too high at commissioning or weather compensation not being enabled. Both are adjustable by a qualified heat pump engineer. Ask your developer to arrange a system review if you are within the defects liability period (typically the first two years).

Is the £7,500 BUS grant available on a developer-installed heat pump in a new build?

It depends on the timing and documentation. The Boiler Upgrade Scheme is primarily targeted at replacing fossil fuel heating in existing homes, but in some new-build scenarios where a heat pump replaces an older system, it may apply. The critical requirement is that the installation must have been carried out by an MCS-certified installer and the property must meet the eligibility criteria. Check the specific rules via our Boiler Upgrade Scheme guide.

What is the Future Homes Standard and when does it affect my new-build purchase?

The Future Homes Standard is a UK building regulation update, expected to be fully in force in 2026, that requires new homes to have significantly lower carbon emissions than those built under older rules. In practice, this means gas boilers are being phased out of new builds and heat pumps are becoming the standard heating solution. If you are purchasing a new-build home from 2026 onwards, it will almost certainly have a heat pump.

Who is responsible for fixing a heat pump in a new build — the developer or the manufacturer?

Both, potentially. During the developer's defects liability period (usually two years), installation and workmanship issues are the developer's responsibility. After that period, the manufacturer's warranty covers component failures — provided annual servicing has been carried out and the system was MCS-certified at installation. It is worth clarifying this split at handover so you are not caught between the two parties if something goes wrong.

Get the Right Advice Before You Commit

Whether you are a buyer about to exchange contracts on a new-build property, or a developer making procurement decisions ahead of the Future Homes Standard, the quality of heat pump specification and installation is the factor that will define whether your home delivers on the promise of EPC A. The gap between a well-commissioned system and a poorly set-up one can amount to hundreds of pounds per year in running costs — and it is entirely preventable.

If you want to compare your options, verify whether your installation meets MCS standards, or simply get independent advice from qualified installers in your area, request quotes from MCS-certified heat pump specialists near you. Independent assessment of your system could pay for itself within a single heating season.