Air conditioning in Letchworth Garden City and Baldock

Two sets of permission in Letchworth, not one

Letchworth was the world's first Garden City, built from 1903 to a masterplan by Barry Parker and Raymond Unwin. The Letchworth Garden City Heritage Foundation now looks after the estate.

The Foundation runs a Scheme of Management, approved under the Leasehold Reform Act 1967. It applies to all freehold premises on the Garden City estate, and many leases carry similar terms. In the Foundation's own words, most homes need its written approval before any external changes are made. An outdoor unit on a wall or on the ground is an external change.

That consent is separate from planning. A unit can be permitted development and still need the Foundation's approval, so you need both in order.

What the Foundation's heat pump guidance asks for

The Foundation published Design Principles for air source heat pumps in June 2025. They apply in both its Heritage and Modern Character Areas, and it says units will usually be approved if they follow them:

• The unit doesn't detract from the character of the property
• It is placed to keep visual and noise impact low for you, your neighbours and the street
• It sits at the rear, or possibly at the side where existing screening already hides it from the street
• It is preferably mounted on the ground rather than on a wall
• It is at least 1 metre from any boundary
• External condensers, pipework and air conditioning units are discreet and can't be seen from the street
• More than one heat pump at a property is discouraged

How we work with Foundation consent

At the survey we look for a rear, ground-level position that meets the guidance, and give you the model, size and sound data for the application. The Foundation's Heritage and Stewardship Team gives free pre-application advice, and applications go through its online portal.

Note the boundary rule: national planning rules dropped their 1 metre boundary limit in May 2025, but the Foundation still asks for 1 metre. It charges a fee only for retrospective applications, after work done without consent. So apply first and fit second.

Planning: North Herts Council

Planning in Letchworth and Baldock is handled by North Herts Council, at the Council Offices on Gernon Road in Letchworth.

A heating-capable unit on a house is often permitted development, with no application, if it isn't cooling-only, is no bigger than 1.5 m³ and passes the MCS 020(a) noise check of 37 dB(A) at neighbours' windows. A semi or terrace can have one heat pump. Our planning guide has the rest.

North Herts has 44 conservation areas. In and around Letchworth they include the Letchworth conservation area, designated in 1974 and amended in 1990, plus Norton, Croft Lane in Norton, and Willian. Baldock has its own conservation area. In any of them, a unit can't go on a wall or roof facing a highway without permission.

The council's Article 4 directions for the Letchworth and Baldock town centres stop commercial premises becoming homes without permission, and don't cover heat pumps. When we checked in October 2026, its conservation area Article 4 directions were for Hitchin and Stockens Green, not Letchworth or Baldock. Listed buildings always need consent.

Letchworth and Baldock homes and what they mean for an install

Air conditioning for Letchworth and Baldock businesses

We fit and look after wall units, ceiling cassettes and multi-split systems for offices, shops, cafes, clinics and workshops, in business hours.

The Scheme of Management covers freehold premises on the estate, not only homes, so check with the Foundation before a condenser goes on a commercial building.

Parking on install day

North Herts runs residents' parking zones in parts of the district, including Baldock Zone A. If your street is in one, tell us when you book. The council can grant a parking dispensation where a vehicle must be parked close to a property for works. It charges £25 per vehicle for up to 7 days and needs the application at least 2 working days ahead.

What air conditioning costs in Letchworth and Baldock

Home prices include VAT. Business prices are plus VAT. The survey turns them into a fixed written price.

• A bedroom or study

  2.5 kW wall unit, 5 m pipe, fitted in a day

  from£1,850inc. VAT

• A living room

  3.5 kW wall unit

  from£2,050inc. VAT

• Two rooms, one outdoor unit

  Multi-split

  from£3,650inc. VAT

• Three rooms

  Multi-split

  from£5,100inc. VAT

• Commercial wall unit

  Fitted in business hours

  from£1,795+ VAT

• Ceiling cassette

  In a suitable suspended ceiling

  from£2,750+ VAT

• An annual service

  Keeps the manufacturer warranty valid

  from£119inc. VAT

• Repair diagnostic visit

  First hour on site, deducted if you go ahead

  from£125inc. VAT

Areas and postcodes we cover

We cover both towns and the villages around them, including:

• SG6: Letchworth Garden City, including Grange, Norton, Wilbury and the south-east and south-west of the town
• SG7: Baldock and villages such as Ashwell, Hinxworth, Newnham and Wallington
• Nearby: Hitchin and Stevenage

Letchworth Garden City questions