Air conditioning installation in Fareham

One recent Fareham enquiry shows the main problem with the borough's houses: a detached house, two bedrooms and a large living room to heat and cool, a budget of £3,000 to £6,000, and the indoor units on the opposite side of the house from the outdoor unit. Fareham is mostly post-war and late twentieth-century family housing, detached and semi-detached, and a lot of it puts the rooms people want to cool on one side and the drive, the side passage or the garden wall on the other.

This page deals with what happens when the indoor units and the outdoor unit are a house apart, and what you can do instead.

What a long pipe run actually costs you

A split system is joined by two insulated copper refrigerant pipes, and in principle they can go a long way. In practice every outdoor unit has limits, which the manufacturer publishes on the datasheet: a maximum pipe length for each indoor unit, a maximum total length for a multi-split, and a maximum height difference between the indoor and outdoor units. Within those limits, each extra metre costs you something.

There is the copper and insulation itself, plus the labour to route it through the loft, behind cupboards or round the outside of the house in trunking. Outdoor units come charged with refrigerant for a set length of pipe, and beyond that the installer has to add more, which takes time and increases the total charge. A larger charge can bring the system closer to the threshold for statutory leak checks, as our multi-split guide explains. Long runs also lose a little capacity, which matters most in heating mode on a cold morning, the time you most want the big living room warm.

There is also one thing a far-side condenser cannot fix. Each indoor unit produces condensate, and that water has to drain close to where the unit is, usually through the wall behind it or by a small pump. Putting the outdoor unit out of sight on the far side still leaves a small pipe or a pump on the side where the rooms are. Ask how each room's condensate will be drained before you accept a design.

Before you compare quotes, ask each installer for the planned pipe length to every room and the datasheet limit it is being measured against.

Two outdoor units instead of one long journey

On a detached house there is often a better option than one long run. Permitted development allows two outdoor units on a detached house, but only one on a house that is not detached [1]. For a layout like the one in that enquiry, that makes another design possible: a single split for the large living room, with its own outdoor unit close to it, and a two-room multi-split for the bedrooms, with the second unit wherever their pipework can reach easily.

A large living room is the room most likely to need a bigger unit, and on a multi-split it shares the outdoor unit's capacity with the bedrooms whenever everything runs at once. With its own outdoor unit it gets full output in winter. The work can also be done in stages: the living room this year, the bedrooms next, without having to size one large unit for rooms you have not done yet.

The limits still apply. An outdoor unit cannot go on a wall above ground floor that fronts a highway, wherever you live, and in a conservation area it cannot go on any wall or roof fronting a highway, nor nearer to the road than the house [1]. Each unit must be placed, as far as practical, where it has least effect on the look of the house [1]. When there are two units, the noise calculation has to include both: the 2025 revision of MCS 020(a) added a method for combining two heat pumps against the 42 dB(A) limit at the neighbour's window [2]. On a quiet Fareham cul-de-sac, that calculation usually decides where the second unit goes.

Will it fit a £3,000–£6,000 budget?

Our estimate for three to four rooms is £4,500–£8,000. A three-room job with straightforward routing can come in within a £6,000 budget. Long hidden runs through a loft and round a chimney, or a second outdoor unit, are what push a quote towards the top of that range or past it. Phasing helps: a single room is £1,500–£3,500 on our figures, and two rooms on one outdoor unit £2,800–£4,500, so the two-unit design spreads naturally over two budgets.

If you want heating as well as cooling, check the grant rules too. The Boiler Upgrade Scheme pays £2,500 towards an air-to-air heat pump [5], but the property must not be left with any fossil-fuel heating [6]. A house that keeps its gas boiler and adds air-to-air for three rooms does not qualify. Our grant eligibility checker works through the rest of the conditions.

Street by street across the borough

Locks Heath, Park Gate, Sarisbury and Warsash

The Western Wards grew into a new settlement in the 1980s on land that used to be strawberry holdings. Many of the detached houses sit close to their neighbours, so the noise calculation matters more than the plot size suggests. Some estate houses are link-detached, joined to the neighbour by a garage. Whether one of those counts as detached for the two-unit allowance is worth confirming with the council before relying on it.

Stubbington and Hill Head

Much of the housing is post-war, with plenty of bungalows. In a bungalow every room is under the same loft, which makes an outdoor unit on the far side much easier to reach. On the Hill Head seafront facing the Solent, specify a unit with an anti-corrosion coil coating and stainless fixings, because salt air shortens the life of a standard outdoor unit.

Portchester

Plenty of semis, which means one outdoor unit under permitted development and multi-splits for more than one room. The old village around the castle is the Portchester Castle Street conservation area [3]. For tight terraced plots on the Portsmouth side, our Portsmouth guide covers siting in small rear yards.

Titchfield and the older centres

Fareham Borough Council has designated conservation areas at Titchfield, Titchfield Abbey, Fareham High Street with its Georgian frontages, Catisfield, Wallington and Warsash, among others [3]. In these areas the ban on outdoor units facing a road covers the ground floor as well as upper storeys, and listed buildings need consent whatever the location [1]. The period home guide covers discreet pipe routing.

Whiteley

The town straddles the boundary between Fareham Borough and Winchester City Council, so check which one covers your house before reading anyone's planning advice.

Welborne

The new garden village north of the M27 at junction 10 had its first residents in 2025, in the Chesterfield neighbourhood, and building continues [4]. New homes are built to tighter airtightness standards and many overheat upstairs in summer, which our new-build guide covers. On any new estate, check the planning permission for conditions that remove permitted development rights, because planning conditions can switch them off [1].

Next step

Send us the floor plan as you would describe it to a friend: which rooms, which way they face, and where you would be happy to see an outdoor unit. That is enough to tell whether a single long-run multi-split or a two-unit design makes more sense. Submit a home enquiry. We'll review your requirements and match you with a suitable installer operating in your area. Our Hampshire guide covers the rest of the county, and for the waterfront flats and suburbs west along the M27, see Southampton.