Spring 2026 Heat Pump Planning Rules Update: What Changed and What Still Catches People Out

What Is the Main Heat Pump Planning Change Homeowners Need to Know in Spring 2026?

The main planning change to know in spring 2026 is that England’s updated permitted development rules have removed the old one-metre boundary restriction for air source heat pumps. According to the Boiler Upgrade Scheme government response published in late 2025, the amendment removed the rule requiring a unit to sit at least 1 metre from the boundary.

That is one of the biggest practical planning simplifications homeowners have seen in recent years.

According to the 2025 permitted development amendment order, the updated rules came into force on 29 May 2025. So in spring 2026, these are not proposed changes or consultation ideas; they are the live rules you should be working from in England.

For broader context, read our heat pump planning permission guide, BUS grant (subject to eligibility) complete guide, and complete guide to heat pumps in the UK.

What Else Changed Under the 2025 Permitted Development Amendment?

The 2025 amendment did more than remove the one-metre boundary rule, because it also widened some rights on unit numbers and sizing. According to The Town and Country Planning (General Permitted Development) (England) (Amendment) Order 2025, detached houses can now have up to 2 air source heat pumps, whilst other dwellinghouses and blocks of flats are limited to 1.

That means the planning position is now more flexible, but still not unlimited.

According to the same statutory instrument, the revised rules also say the air source heat pump must not be used solely for cooling. So the regime has become broader, but it is still tightly defined.

Do Flats and Larger Homes Have Better Options Now?

Yes, the rules are better for some flats and larger homes than they were before, because the amendment explicitly covers blocks of flats and allows up to 2 units for detached houses. According to the 2025 order and the associated impact assessment, the changes were designed to reduce planning bureaucracy and support more installations on dwellinghouses and blocks of flats.

That is a meaningful change in real-world project planning.

According to the Regulatory Policy Committee opinion published on GOV.UK, the amended rights are deregulatory in effect and reduce planning costs and bureaucracy. The same document says the changes support ASHP installation on or within the curtilage of a dwellinghouse or block of flats, which is especially relevant for building owners assessing low-carbon retrofit options.

The practical improvements are strongest where:

1. the old boundary rule was the main barrier
2. a detached home needs 2 units for technical reasons
3. a block or flat scheme wants clearer permitted development treatment
4. the installation can still satisfy the remaining size and sound conditions

What Still Triggers Caution Even After the Rule Changes?

The rule changes make planning easier, but they do not make every heat pump automatically permitted development. According to the 2025 amendment order, installations must still comply with current MCS Planning Standards, and the revised rules still contain size, number and use conditions that can stop a proposal falling within permitted development rights.

That is why “easier” is not the same as “no checks needed”.

The main caution points are:

1. unit size limits still apply
2. number-of-unit limits still apply
3. MCS sound-calculation standards still matter
4. non-standard homes or local restrictions can still create planning risk

According to the amendment order, the relevant MCS Planning Standards reference has been updated to MCS 020 sound-calculation standards. According to the BUS government response, government also recognises that more barriers remain and that further improvements may still be considered after consultation feedback.

What Do the Current Planning Rules Mean for BUS Grant (subject to eligibility) Projects?

For BUS grant (subject to eligibility) projects, the current planning rules matter because easier permitted development reduces friction in the installation journey, but it does not remove the need for a proper technical survey. According to the BUS government response, changes such as the boundary-rule removal sit alongside wider BUS adjustments intended to broaden access from 2026/27 onwards.

That means grant access and planning access are both moving in a more flexible direction, but they are not the same test.

According to GOV.UK’s March 2024 announcement, removing mandatory loft and cavity wall insulation for BUS could cut costs by around £2,500 on a semi-detached home. That is separate from planning reform, but both changes point in the same direction: fewer avoidable barriers to switching from a boiler where the home is otherwise suitable.

If you are comparing grant routes and planning constraints, also read our heat pump installation process guide, is your home suitable for a heat pump guide, and heat pump cost guide.

What Does This Mean for London and Surrey Homes in Spring 2026?

For London and Surrey homes, the new rules matter because tight side passages, close boundaries and mixed housing types used to complicate heat pump siting much more often. According to GOV.UK’s 2024 announcement, the wider BUS changes could reduce costs on a semi-detached home by around £2,500 where old insulation prerequisites had previously acted as a barrier.

That local relevance is strongest in:

1. terraced and semi-detached housing with limited outdoor space
2. detached homes needing more than one external unit
3. flats and blocks considering building-wide retrofit
4. homes where sound, siting and neighbour impact still need careful design

In practice, London and Surrey homeowners should treat spring 2026 as a better planning environment than spring 2024, but not as a reason to skip technical due diligence. The more constrained the site, the more important it is to get the location, sound calculation and overall system design right from the start.

How Electromatic Can Help

If you are unsure whether your project falls within current permitted development rights or still needs extra checks, Electromatic can assess the site properly before you commit. According to GOV.UK and the 2025 amendment order, the rules are simpler than before, but size, sound and property-specific conditions still matter.

We help homeowners across London, Surrey and nearby TW areas work out whether the next step is a heat pump route supported by the BUS grant, subject to eligibility, or a broader staged upgrade plan. We work under MCS certification via our accredited umbrella partner, so established low-carbon heating routes follow the correct compliance framework.

Book your free home survey →

Call us: 07718 059 284 | Email: admin@electromatic.uk

Frequently Asked Questions

The planning rules matter in 2026 because they are easier than they used to be, but they are not completely open-ended. According to GOV.UK and the 2025 amendment order, the one-metre boundary rule has gone, yet size, unit-number and standards-based conditions still apply, which is why these are the practical questions homeowners usually ask.

Do I still need 1 metre from the boundary for a heat pump?

No, not under the current amended permitted development rules in England. GOV.UK’s BUS government response confirms that the old one-metre boundary rule has been removed.

Can a detached house now have 2 heat pumps?

Yes, under the 2025 amendment order a detached dwellinghouse can have up to 2 air source heat pumps under permitted development, subject to the other current limits and conditions.

Do flats have any permitted development option now?

Yes, the amended rules explicitly refer to blocks of flats. But the current limits are tighter, including a 0.6 cubic metre outdoor-unit size limit for a block of flats.

Do I need planning permission in every case?

No, not every case. But you still need to check whether the installation fits the current permitted development rules and any other site-specific constraints.

Is the planning change the same thing as BUS grant eligibility?

No. Planning rights and BUS grant rules are related to the same project, but they are not the same test. A project can be easier to site under planning rules and still need separate grant-eligibility checks.

The information in this article is for general guidance only and does not constitute financial, legal, or technical advice. Energy savings estimates are based on typical UK household data from the Energy Saving Trust and Ofgem (April 2026 price cap). Actual savings depend on your property type, insulation levels, energy usage patterns, and electricity tariff. The Boiler Upgrade Scheme (BUS) grant of £7,500 is subject to eligibility criteria set by Ofgem — not all properties qualify. Electromatic M&E Ltd operates under MCS certification via an accredited umbrella partner. All installations comply with Building Regulations Part L and MCS standards. E&OE.

Written by Electromatic M&E Ltd — ASHP & Solar installer, London & Surrey (electromatic.uk)

Last updated: April 2026 | Electromatic M&E Ltd, Company No. 13837345