Office air conditioning in London: landlord consent and planning

Start with the lease

Office leases in London usually let you the inside of your floor and reserve the structure, roof, external walls, risers and shared plant areas to the landlord. Any air conditioning that needs an outdoor unit, a pipe route through a riser, a core through a wall or a connection to building drainage will touch something the landlord owns. That means a licence for alterations.

Read these parts of your lease first:

• the alterations clause: what needs consent, and whether consent can be unreasonably withheld
• any rights to use plant space or the roof
• the reinstatement clause: whether you must remove the system at the end of the lease
• service charge provisions if the building has central cooling

What landlords usually ask for

In the City of London and other central office districts, landlords and their managing agents commonly ask for a pack like this:

Item	Why they want it
Drawings of indoor units, pipe routes and outdoor unit location	to check impact on the structure and other tenants
Equipment specifications	to check weight, power and refrigerant
Noise data and, where needed, an acoustic report	to protect neighbours and comply with planning
Method statement and risk assessment	for safe working in a shared building
Programme and working hours	to manage lifts, loading bays and disruption
F-gas company certificate	to confirm legal refrigerant handling
Insurance certificates	public liability and contractor cover
Electrical design	power capacity and Part P or commercial standards

Some buildings also want a landlord’s mechanical engineer to review and sign off the design, and some insist on approved contractors. Build the time for this into your plans.

Planning for commercial plant

The permitted development right for air source heat pumps applies to houses and blocks of flats only (Planning Portal). Planning Geek notes that units on commercial premises require planning permission. For an office, a new outdoor unit on a roof, wall or yard will normally need an application.

The City of London has 28 conservation areas, according to the City Corporation, and many buildings are listed. Noise is often the deciding issue in central London. Neighbouring Westminster, for example, asks in its noise guidance that plant in noisy areas runs 10 dB below the lowest background level at the nearest noise sensitive window. Where offices sit near homes, as they do around the Barbican, Smithfield and the City fringes, expect councils to look closely at noise.

Sometimes there is an easier route. If the building has spare capacity on a central system or a landlord’s existing plant area, connecting to it may avoid a new outdoor unit altogether.

Working in a City building

City buildings have strict rules for contractors:

• lift and loading bay bookings, often days in advance
• permits for hot works, such as brazing pipes
• limits on noisy work, like core drilling, during office hours
• out of hours access and security arrangements
• site inductions for engineers

Agreeing these with the building manager before the start date avoids delays on the day. For phased installs, floors or zones are done in turn so staff can keep working. Our City of London area page covers the local picture.

Legal duties once it is in

Owning or operating an office air conditioning system brings some ongoing duties:

• F-gas leak checks for equipment holding 5 tonnes of CO2 equivalent or more, with records (gov.uk)
• TM44 inspection at least every five years for systems over 12kW effective rated output, explained in our guide to TM44 inspections
• Servicing to keep it efficient and within warranty

Check with the landlord who is responsible for each. In some buildings the landlord maintains plant under the service charge, while in others the tenant maintains its own system.

Choosing the right system

Once consent is in view, the design can go ahead: cassettes for open plan, ducted or wall units for meeting rooms, and a dedicated unit for comms rooms. Our guide to ceiling cassette or wall mounted units helps with that choice, and our office air conditioning page explains how a commercial job runs from survey to handover.

A typical timeline

Every building is different, but a realistic sequence for adding cooling to a let office looks like this:

Stage	What happens
Lease review	you or your surveyor check the alterations, plant and reinstatement clauses
Survey and outline design	unit types, positions, outdoor unit location, power and drains
Landlord pre application	informal check with the managing agent on locations and rules
Licence pack	drawings, specifications, noise data, method statements, certificates
Planning application	where new external plant is needed
Licence and planning granted	formal consents in place
Programme agreed	lift bookings, out of hours working, permits
Installation and commissioning	phased if needed, with handover records

Starting the lease review and the landlord conversation early is the single biggest time saver. Planning applications for plant can take weeks, so if you want cooling ready for summer, begin in winter.