Garden rooms and outbuildings — detached garden offices, studios, gyms and hobby rooms — are increasingly common in UK gardens, and air conditioning is increasingly standard in them. Here is a practical guide to the options and considerations.
Why Garden Rooms Need Air Conditioning
A garden room that is not connected to the main house central heating or cooling system relies entirely on its own climate control. Typical garden rooms have significant glazing areas — for light and the garden view — which creates both high solar gain in summer and significant heat loss in winter. Without active climate control, a garden room is too hot from April to October and too cold from November to March.
Air conditioning provides both cooling in summer and efficient heat pump heating in winter — making the garden room genuinely usable year-round. For a professional using a garden office full-time, this is essential.
The Pipework Challenge — How to Get Refrigerant to the Garden
The outdoor unit must go somewhere accessible — it cannot go inside the garden room and should not be squeezed against the garden room wall without adequate airflow clearance. The two main approaches:
Outdoor unit adjacent to the garden room: The simplest approach. The outdoor unit goes on the wall of the garden room or on a bracket/pad immediately outside. Short refrigerant pipe run (typically 2-4 metres), low cost. Potential visual impact of the outdoor unit on the garden room exterior.
Outdoor unit at the main house, underground pipe run: The refrigerant pipework is run underground between the main house and the garden room — buried in a protective conduit at a depth of 300-600mm. The outdoor unit is positioned at the main house (on the wall, in the side return or wherever is convenient). The garden room exterior is completely clean — no outdoor unit visible. The underground run costs approximately £300-600 depending on distance. This is our preferred approach for quality garden office installations where the garden is important to the owner.
Insulation and Sizing
Garden rooms typically have lower insulation values than a main house room — many garden rooms use 50mm or 75mm insulation compared to 100mm+ in a modern house wall. This means the heat load per square metre is higher and a slightly larger unit is required than a comparable internal room.
Also consider the glazing area — a garden room with a large south-facing glass wall facing the afternoon sun needs significantly more cooling capacity than its floor area alone suggests. We always calculate properly for garden room installations rather than using a simple size rule.
Cost
Garden room installation with outdoor unit adjacent to the garden room: £1,400-2,000. Garden room installation with underground pipe run to main house: £1,800-2,800 depending on run length. Call 07833 053749 or request a free site survey.