Heat Pump for Scottish Tenement Flat UK 2026

Scottish tenement flats share these features:

• Stone construction: solid sandstone (yellow/red) or granite walls 500-700mm thick. U-value 1.2-1.8 W/m2K.
• Common stair access: 'close' or 'stair' shared by 4-12 flats per stair.
• Rear court ('back green'): communal courtyard shared with neighbouring flats (typically 2-8 flats).
• Tenement title deed: each flat's title shares 'common property' (stair, hallway, rear court, roof).
• Factor or property management: appointed factor manages common-property maintenance + approval of significant alterations.
• Listed building protection: ~30-40% of Edinburgh + Glasgow tenements are Grade B Listed (Scottish equivalent of UK Grade II); some Grade A (UK Grade I) in Conservation Areas.
• Original window features: sash + case windows, often single-glazed; replacement subject to listed-building consent.

Ground floor flat (sometimes basement / lower-ground):

• Rear court access typically simple.
• Outdoor unit fits in shared back green (with consent).
• Refrigerant pipework routes via rear wall window or rear external wall.
• VIABLE for typical install path.

First floor flat:

• Rear court accessible via wall-mounted outdoor unit + decorative or service bracket.
• Refrigerant pipework via rear-facing window or external wall.
• VIABLE with bracket-mounted outdoor unit.

Second floor and above:

• Rear court too far for refrigerant pipework (4-15m vertical drop).
• Outdoor unit cannot be mounted on rear facade (typically refused listed-building consent + neighbour objection).
• Common roof access shared with all flats - unrealistic for single-flat install.
• RARELY VIABLE in current state of UK ASHP technology.

Upper-floor alternatives:

• District heat networks: Edinburgh + Glasgow expanding district heat in 2025-2030; ARRANGE FIRST.
• Air-to-air heat pumps (split units): outdoor unit on internal wall via window penetration; works but ugly + planning consent obstacles.
• Improved gas boiler + insulation: keep boiler for now while waiting for district heat or technology improvements.

1. Pre-application Conservation Area consultation with Edinburgh / Glasgow Council Conservation Officer.
2. Listed Building Consent if Grade A or B (most central Edinburgh/Glasgow tenements).
3. Planning permission for outdoor unit visible from public viewpoint.
4. Factor consent: approach factor to confirm rear court / external wall use.
5. Neighbour notification: written notice to all flats sharing the rear court (typical 4-8 flats).
6. Heat-loss survey: stone walls = high U-value, results in 4-7 kW heat load typical.
7. Install: 7 kW R290 heat pump; 200L unvented cylinder; 22mm pipework run; commissioning.
8. Total lead time: 4-6 months from quote to install (vs 4-8 weeks typical UK home).

Solid stone walls in Scottish tenements (sandstone or granite) have higher heat loss than equivalent cavity brick:

• 500mm sandstone: U-value 1.2-1.5 W/m2K.
• 500mm granite: U-value 1.5-1.8 W/m2K.
• Compare to filled cavity brick: U-value 0.55-0.65.

Insulation options (most are listed-building restricted):

• External Wall Insulation (EWI): USUALLY REFUSED in listed tenements (visual alteration of facade).
• Internal Wall Insulation (IWI): requires listed-building consent; LOSES 50-100mm of internal floor space per wall.
• Decorative skim insulation (10mm cork board + plaster): minor heat loss reduction; often acceptable to listed-building consent.
• Window upgrade to secondary glazing: typically permissible (interior addition not visual change). Cost: GBP 800-1,200/window.

Viable ground/first floor install:

• 5-7 kW heat pump unit: GBP 7,500-9,500.
• 200L unvented cylinder: GBP 1,200-1,700.
• Pipework + commissioning: GBP 1,500-2,500.
• Listed Building Consent + Planning + Factor fees: GBP 1,000-2,500.
• Acoustic enclosure (often required by neighbour consultation): GBP 800-2,000.
• Secondary glazing (if budget): GBP 3,000-6,000.
• BUS grant: -GBP 7,500.
• Net total: GBP 7,500-15,200.

Home Energy Scotland grant (Scottish equivalent to BUS):

• GBP 7,500 grant available (matches BUS).
• Additional grant: up to GBP 8,500 for households on benefits / low income.
• Combined max: GBP 16,000 in some cases.
• Apply via energysavingtrust.org.uk/scotland.

For 2nd+ floor tenement flats with no viable outdoor unit siting:

• Wait for district heat network expansion: Edinburgh Granton District Heating Network expanding 2025-2030; Glasgow Govan District Heating launching 2026. Both will connect tenement clusters.
• Improved gas boiler + envelope: keep modern A-rated condensing boiler; add secondary glazing + improved roof insulation (~GBP 2,000-5,000); achieve EPC D-C without heat pump.
• Air-to-air split heat pump: single-wall-mount internal unit + external bracket; smaller scale (4 kW typical) for primary room only; supplementary electric or gas for other rooms.
• Move: realistic for some - tenement upper-floor flats with no viable heating decarbonisation path may need to plan around district heat timeline.