The Government’s newly unveiled £15 billion Warm Homes Plan risks becoming a "costly mistake" by prioritising high-tech heat pumps over basic insulation.
The Builders Merchant Federation (BMF) say that removing mandatory insulation requirements from the Boiler Upgrade Scheme allows homeowners to install expensive low-carbon heating into "leaky" properties that cannot retain the warmth.
Without a "fabric first" approach, they warn thousands of homeowners could be left with underperforming systems and unexpectedly high energy bills.
The insulation omission
While the Government has pledged nearly £15 billion to upgrade five million homes, the BMF has voiced serious concerns regarding a lack of focus on the building's "fabric."
Since May 2024, Ofgem has removed the requirement for loft or cavity wall insulation to be in place before a homeowner can claim a £7,500 Boiler Upgrade Scheme grant.
BMF CEO John Newcomb argues that the current strategy is fundamentally flawed, stating: “It seems illogical that a £7,500 Boiler Upgrade Scheme grant can be claimed without measures to properly insulate homes first.”
For renovators, this policy shift creates a risk of installing advanced tech that the home simply isn't ready for.
The 'bath without a plug' warning
The criticism centres on the efficiency of low-carbon technology in poorly insulated spaces. Mike Beard, Chair of the BMF’s Insulation and Dry-Lining Forum, describes the current policy as "like running a bath and not putting the plug in."
Because heat pumps typically operate at lower flow temperatures than traditional gas boilers, they require a well-insulated environment to function effectively.
“It’s imperative that we don’t lose sight of the need for fabric-first, well-insulated properties,” Beard warns, noting that failing to do so will cause the benefits of energy-efficient measures to “backfire” as heat escapes faster than it can be generated.
Calls for a fabric-first future
The BMF is now calling for the Warm Homes Plan to be "re-plumbed" with a fabric-first strategy.
CEO John Newcomb argues that while the £15 billion allocation is a welcome "long-overdue" investment, the logic of subsidising £7,500 for a heat pump without ensuring the home can hold that heat is "illogical."
The federation is urging the Government to reintroduce measures that ensure insulation is installed professionally and prioritised as the foundation of any home renovation to ensure the UK’s housing stock is truly fit for a net-zero future.
