Does a edwardian semi-detached qualify for the Boiler Upgrade Scheme?

Yes — the £7,500 BUS grant applies to any owner-occupied or privately rented property in England or Wales with a valid EPC. Solid-wall recommendation almost universally present on EPC — internal or external wall insulation needed before BUS sign-off, OR a documented exemption.

What size heat pump do I need for a edwardian semi-detached?

9–14 kW thermal output is typical, with 12 kW being the median. The exact size depends on a heat-loss calculation per BS EN 12831, which your MCS-certified installer performs on a site visit.

What pre-install work is typically needed?

Solid-wall insulation OR formal exemption paperwork to clear the EPC recommendation. Loft insulation to 270 mm. An MCS-certified installer will confirm the exact scope on a site visit and price it into the quote.

Heat pump for a Edwardian semi-detached: 2026 cost + sizing guide

What makes a edwardian semi-detached different

Early-20th-century semi-detached house with solid walls, large bay windows and typical 95–140 m² floorplate.

From a heat-pump-sizing perspective, a edwardian semi-detached has a design heat loss of 70–100 W/m² at the UK standard −2°C external design temperature (per PAS 2035). That translates to an annual space-heat demand of around 14,000–23,000 kWh and a recommended air-source heat pump capacity of 9–14 kW thermal. Smaller than gas-boiler sizing typically lands at — heat pumps run 24/7 at lower flow temperatures rather than cycling at 70°C.

Heat pump sizing + install figures — Edwardian semi-detached
Parameter	Typical range	Notes
Floor area	95–140 m²	BEIS English Housing Survey median.
Design heat loss	70–100 W/m²	At −2°C external (UK design temp).
Annual heat demand	14,000–23,000 kWh	Space heating only, not DHW.
Recommended ASHP size	9–14 kW	Per BS EN 12831 sizing.
Pre-grant install cost	£12900–£19400	Including pump, cylinder, 1–3 radiator upgrades.
After BUS grant	£5400–£11900	£7,500 deducted by installer at invoice.
Common EPC band	Band E	Before retrofit work.
Typical install time	2–3 days	Whole-house including cylinder + radiator swaps.

Heat pump sizing + install figures — Edwardian semi-detached— Ranges are typical for the archetype; specific quote depends on property survey by an MCS-certified installer.

BUS grant eligibility specifics for this property type

Solid-wall recommendation almost universally present on EPC — internal or external wall insulation needed before BUS sign-off, OR a documented exemption.
Most Edwardian semis sit in mature streets where ASHP outdoor-unit placement is straightforward (side return, often hidden from highway).
Floor area at the upper end of the range pushes the unit size near the 14 kW MCS-installer ceiling — confirm headroom in your heat-loss calc.

Pre-install upgrades typically needed

Most edwardian semi-detacheds need some fabric or radiator work before the heat pump can be commissioned. The most common scope:

Solid-wall insulation OR formal exemption paperwork to clear the EPC recommendation.
Loft insulation to 270 mm.
Radiator upgrade in 2–4 rooms — Edwardian rooms have high ceilings + bay windows so per-room heat demand is significant.
Hot water cylinder install (~£1,500–£2,500) if currently combi-only.

The full scope is set by your MCS-certified installer’s heat-loss calculation. Most installers absorb the radiator swap and cylinder install within the BUS-grant pricing — you don’t have to coordinate them separately.

Is this archetype right for you?

Owner-occupiers in solid-wall heritage stock willing to fund the fabric retrofit. Once done, the home performs at band C levels — strong resale uplift.

Check your specific home

The figures above are typical for the archetype. Your specific property may sit at either end of the range depending on orientation, occupancy and prior retrofit work. Run a free Propertoasty pre-survey — combines your address, EPC and Google Solar API roof data into an installer-ready report in about five minutes.