Building a house with a pool in Batumi: shell, plant room and plot

The pool is planned together with the house

When building a house with a pool in Batumi, we design the two as a single project: the pool shell, the plant room, the pipework and the electrics appear on the site plan and in the services drawings at the same time as the house. The pipe runs to the pool are laid while the trenches for the house services are open, the power drawn by the pumps and heating is included in the overall incoming supply, and room for the plant room is left in the basement or in a separate outbuilding.

There is a practical reason too. The pool excavation is dug by an excavator, the concrete arrives in a mixer truck with a pump, and a composite (fibreglass) shell is set in place by crane. Once the house is built, the fence and gates are up and the yard is paved, machinery often can no longer get through. So we schedule the earthworks and the shell while the way to the pool site is still clear, and leave the lining and commissioning until nearer the end, together with the finishing of the house.

Where to put the pool on the plot

We choose the spot by the sun, the wind, the ground and the distance to the foundations, together with the landscape design for the plot, so that deciduous trees don't end up hanging over the water.

Setbacks from the plot boundary are set by the zone, so we check them against the zoning rules before the sketch. On a slope, water from the plots above flows across yours, and unless it is intercepted, it will carry soil and leaves into the pool. How the terraces and retaining walls are built is covered on the page about houses on a slope.

The shell: concrete, waterproofing and built-in fittings

We pour a concrete shell as one cast-in-place structure, using concrete of the water resistance grade specified in the design. The built-in fittings, that is the skimmers, return inlets, main drain and underwater lights, go into the formwork before the pour, each with its own flange: in a finished shell you can no longer cut out a space for them without risking a leak. We try to pour the floor and the walls without a long break, and where a joint can't be avoided we put a waterstop in it.

Concrete on its own isn't fully watertight, so on the inside the shell gets a brush-on waterproofing with reinforcing tape in the corners and around the fittings. Before lining, we fill the shell and watch the water level for several days, and we photograph the waterproofing: once the mosaic is on, it can no longer be seen.

A composite shell arrives from the factory ready-made. It is set on a concrete slab, backfilled and connected within a few weeks, but its size is limited by what can travel along the street to your plot, and its shape by the manufacturer's catalogue. Where groundwater is high, an empty composite shell can be pushed upwards, so it is never left without water.

The weight of the water and groundwater

An 8×4 m pool with an average depth of one and a half metres holds about 48 tonnes of water. On level, firm ground the weight is usually not the main concern: more soil by weight comes out of the excavation than is later taken up by the water and the concrete. Weight matters where the pool stands on fill, on the edge of a slope or above a room: then its supports are calculated by the structural engineer.

On low-lying plots near the sea the problem is the reverse. If groundwater stands high, its pressure from below can lift an empty shell when the pool is drained for repairs. So, depending on the ground survey data, we lay drainage with a sump under the floor of the pool and fit a hydrostatic relief valve in the floor: it lets groundwater in when its pressure rises, and the shell stays where it is.

The plant room and the pool's services

A pump works more easily when it sits at water level or below: it doesn't have to draw the water upwards and doesn't lose its prime when it stops. So we put the plant room close to the pool, in the basement of the house, under the terrace or in a separate outbuilding, and away from the bedrooms. We work out its size from the equipment: the filter, pumps, heat exchanger or heat pump, the dosing or electrolysis unit, and the control panel.

A pool can be a skimmer pool or an overflow pool. In a skimmer pool the water leaves through openings in the wall of the shell, which is simpler and cheaper. In an overflow pool it spills over the edge into a channel, and the water surface sits flush with the surround, but this needs a balance tank nearby and more pipework. We make the choice before the design, because it changes both the shell and the plant room. The pool's electrics run on a separate circuit through an RCD, and the underwater lighting works at a safe extra-low voltage.

Salt or chlorine

In both cases the water is disinfected by chlorine; the difference is where the chlorine comes from. In the classic set-up a dosing unit adds tablets or liquid, and the chemicals have to be bought and kept dry. With electrolysis, salt is added to the water once, and a cell produces chlorine from it by itself. The water is softer, there is less smell and no daily dosing, but the pH still has to be monitored, and the cell is replaced over time.

The water in such a pool is less salty than seawater, but it still eats into metal and stone around the edge. If you choose salt, we use stainless steel made for salt water for the ladders and fittings, and dense coping stone with low water absorption. We don't recommend porous limestone or travertine for this kind of pool: the salt crystallises in the pores and crumbles the surface.

Winter and winterising: what we build in during construction

On the coast a pool is usually winterised rather than drained for the winter, and this is easy to plan for during construction. All the pipes are laid to fall towards the plant room, with drain valves at the low points, so that in autumn the water can be lowered below the skimmers and the pipe runs emptied without breaking up the surround. Plugs for the skimmers and return inlets are bought straight away, together with the equipment.

A downpour raises the water in a pool faster than you might think, so the rainwater overflow is taken into the plot's stormwater drains. The water from backwashing the filter goes into the sewer or a separate soakaway as the design specifies, but not into the septic tank: the chlorine and that volume of water stop it working properly. An automatic cover is also decided at the shell stage, because its roller needs a recess at one end. The winterising itself can be ordered each season as seasonal winterising of the house, and the care of the water in summer can be handed over along with villa management.

The cost of a house with a pool in Batumi

A mid-range turnkey house together with an 8×4 m concrete pool costs from 2,160 to 2,580 ₾ per m² of the house. This price covers the house itself and the pool, with its shell, waterproofing, lining, filtration and surround, and the cost of the pool is spread over the floor area of the house. The bigger the house, the smaller this addition per square metre. Priced separately, a turnkey concrete pool costs from 75,000 ₾, a 6–7 m composite shell with installation and equipment from 51,000 ₾, and a house without a pool from 1,680 ₾ per m².

A timber deck, a pergola and landscaping for the rest of the plot are not included in this price and are listed as separate lines. An overflow pool, a pool on a slope, high groundwater, heating and an automatic cover all cost more. In-season maintenance costs from 600 ₾ a month, chemicals not included. We send a preliminary estimate within 24 hours on business days, and the final cost is set on the basis of the design, after a visit to the plot and once the estimate is agreed. If the pool is going to be part of a large premium house, see the figures for villa construction.