Heat Pump Space Requirements + Floor Plan UK 2026

Physical dimensions (5-12 kW R290 units):

• Vaillant aroTHERM Plus 7 kW: 765 x 1100 x 450 mm (W x H x D).
• Octopus Cosy 6: 990 x 760 x 365 mm.
• Daikin Altherma R 6 kW: 740 x 880 x 330 mm.
• Mitsubishi Ecodan PUZ-WM 60: 950 x 880 x 330 mm.

Clearance requirements:

• Front (air discharge): 2m+ clear for airflow.
• Rear (air intake): 0.5-1m clear depending on model.
• Sides: 0.3-0.5m clear for service access.
• Above: 1-2m clear (for service + airflow).
• Distance from boundary: 1m+ for permitted development; 1.5-2m+ for acoustic comfort.
• Distance from neighbour windows: 4-5m+ for acoustic comfort.

Foundation: level concrete pad (typically 1.2m x 0.7m x 100mm thick), or wall mount on outdoor wall (for some smaller units).

1. Rear garden adjacent to back wall. Most common UK semi-detached / terraced. 1.5m from boundary, screened with timber slat panel. Easy pipework run through back wall.
2. Side passage along driveway. Common detached UK property. Concrete pad in side passage; pipework runs along outside wall.
3. Front corner of rear garden. When rear garden width is tight; corner placement maximises distance from neighbours on both sides.
4. Detached outbuilding or coach house. Some properties (rural, larger gardens) site outdoor unit in dedicated structure for noise + visual screening. Longer pipework runs but acoustic + character benefits.
5. Wall-mounted (smaller units only). Some compact R290 units (5-7 kW) suitable for wall mounting. Saves ground space; requires structural wall.

Most UK heat pump installs include a 200-300L hot water cylinder + sometimes a small buffer tank.

Typical cylinder dimensions (200L):

• Diameter: 545-600 mm.
• Height: 1300-1500 mm including isolation valves at top.
• Footprint with insulation jacket: ~0.6m x 0.6m floor area.
• Service clearance: 200-300mm above for valve access; 500mm in front for service.

Typical cylinder dimensions (300L):

• Diameter: 600-650 mm.
• Height: 1700-1900 mm.
• Floor + service: ~0.7m x 0.7m floor area + clearances.

Best indoor locations:

• Airing cupboard: ideal - usually 0.8-1.2m wide x 0.6-1m deep x 2m tall. Standard cylinder fits with room for spare clothing storage above.
• Utility room: acceptable - dedicated 1m x 1m floor area in corner of utility room.
• Boiler cupboard (replacing gas boiler): often too small for cylinder. Old gas-combi cupboard ~0.5m x 0.5m x 1.5m - need to expand to 0.6m x 0.6m x 2m for cylinder.
• Garage corner: last resort - cylinder works in garage but heat losses higher (unheated space).

Buffer tank (if specified): additional 50-100L cylinder ~400mm diameter x 700mm tall typically. Mounted near main cylinder; not always required.

Pipework routing typically uses minimal visible space:

• Outdoor unit to indoor cylinder: 22-28mm flow + return pipes (~50mm diameter with insulation). Typically runs through outside wall + along wall surface or in voids.
• Indoor cylinder to radiators: 22mm primary pipework, runs in floor voids or against walls.
• Condensate drain: small 22mm pipe + heat-traced cable for cold-climate locations.
• Electrical cable runs: 4-6mm2 cable from consumer unit; outdoor unit controller + isolation switch.

Pipework routing rarely the limiting factor - most properties can accommodate without significant disruption. Major challenges: chasing solid walls (listed properties), running through structural members, accommodating long horizontal runs (large properties).

Some UK properties pose space challenges:

• Small terraced houses: tight rear gardens (under 5m deep), narrow side passages, limited indoor space. Solutions: compact heat pump variant (Vaillant aroTHERM Sound Reducer, Octopus Cosy 6 compact); slimline cylinder (450mm diameter unvented); wall-mounted outdoor unit; combined heat-pump-with-integrated-cylinder unit.
• Basement flats: no outdoor space access. Air-source heat pump usually NOT viable; consider ground-source heat pump via communal bore or shared with adjacent properties.
• Tiny rear gardens: outdoor unit takes significant proportion of garden. Consider wall mounting + corner siting + clever screening.
• No airing cupboard: create one via stud wall partition; or use combination unit with integrated cylinder + heat pump indoor section.
• Listed buildings + conservation: sympathetic siting (outbuilding, recessed alcove) often required as planning condition.

1. Proposed outdoor unit location: measure footprint area, clearances on all sides, distance from boundary, distance from neighbour windows.
2. Proposed indoor cylinder location: measure floor area, height, door access width.
3. Existing electrical supply: consumer unit capacity, free MCB slots, supply rating.
4. Existing radiator inventory: measure each radiator dimensions (heat pump may need oversized replacements for low flow temp).
5. Cold-water supply position: for cylinder cold-feed connection.
6. Condensate drainage option: nearest soakaway, surface water drain, or splash pad location.

Provide floor plans or photos at quote stage so installer can size the unit + plan install before survey visit.