Energy-efficient houses in Batumi: built for the coastal climate and the Adjara mountains

An energy-efficient house in Georgia is often pictured along northern lines: thick insulation and all the attention on winter. Energy-efficient houses in Batumi have a different job to do. The winter is mild, while the summer is long, hot and humid, and the house needs cooling and dehumidifying just as much as heating. So we design the envelope and the building services for both seasons: in winter the house holds on to its heat, and in summer it keeps out the sun and the damp.

Energy-efficient houses in Batumi: Georgian law and the Passive House standard

Georgia has a law on the energy efficiency of buildings. It sets minimum energy performance requirements for new buildings, provides for an energy performance certificate and a gradual move to nearly zero-energy buildings. The law has been amended, and it doesn't apply to every building, so we check the requirements for your house with the architect under the rules in force in 2026, as of the date the documents are submitted.

The law doesn't require a passive house. Passive House is a voluntary standard developed by the Passive House Institute in Germany. A house built to it uses very little energy for heating and cooling, its envelope is tested for airtightness, and compliance with the standard is confirmed by an independent certifier.

An envelope without thermal bridges

A thermal bridge forms wherever heat finds a way around the insulation: a balcony slab that runs through to the outside, a lintel over a window, a column within the masonry, the plinth. In Batumi not much heat escapes through these spots, but in winter moisture collects on them. Humid air condenses on the cold concrete, and mould appears in the corner. So we draw each of these details separately in the design:

• we fit the brackets of a ventilated facade with thermal break pads, otherwise each one carries the cold through the insulation;
• we separate balcony and terrace slabs from the floor slab with thermal break elements, as the structural engineer calculates, or insulate them on all sides;
• we insulate the plinth and the ground-bearing slab with extruded polystyrene, which water doesn't harm;
• we take pipes and cables through the envelope in airtight grommets, so as not to break the vapour barrier;
• we insulate the roof more thickly than the walls, because in summer that is where most of the sun's heat gets into the house.

The thickness of the layer is calculated by a building physics engineer, and on our walls it is usually 100–150 mm of mineral wool. On the sea-facing side the facade over the insulation is more often ventilated, and in a sheltered spot rendered; there is more on this in our comparison of a ventilated facade and ETICS.

Windows, sun and overheating

A window loses heat not only through the glass but also through the frame and the installation joint. We set the frame forward into the insulation layer, take the insulation over the frame on the outside, and seal the joint with tapes: a vapour barrier tape on the inside and a vapour-permeable one on the outside that keeps out wind-driven rain. In Batumi a double-cavity glazed unit with a low-e coating is usually enough, with solar control as well on south- and west-facing windows. We choose the profile to suit the location: aluminium and uPVC by the sea behave differently.

In summer the main concern is the sun. A large west-facing window that looks great in the concept drawing turns the living room into a greenhouse by July, and the air conditioning runs non-stop. Roof overhangs and canopies over south-facing windows help, as do external blinds or roller shutters on west-facing ones, and solar control glass where shade isn't possible. Curtains inside do little: by then the heat has already come through the glass and stays in the room.

Ventilation with heat recovery, and humidity

An airtight house without ventilation soon gets damp: showers, cooking and breathing produce moisture every day, and it has nowhere to go. So here a mechanical supply and extract ventilation unit runs all the time. Fresh air is supplied to the bedrooms and living room and extracted from the kitchen and bathrooms, and the heat recovery unit between the two airflows passes the warmth of the outgoing air to the fresh air in winter, and its coolness in summer.

For Batumi we usually fit an enthalpy heat recovery unit. It also transfers some of the moisture between the airflows, so in the sticky heat of July the supply air brings less damp into the house. It doesn't fully dry the air: in summer the air conditioners do that job, and between seasons a separate dehumidifier may be needed. We position the unit so that the filters, which are changed several times a year, can be reached without taking the ceiling apart.

Heat pump and solar panels

An airtight house needs little heating capacity, and the simplest way to provide it is an air-to-water heat pump with underfloor heating or fan coil units, which also cools the house in summer. A heat pump costs from 14,400 ₾ installed, and its output is chosen by a heat loss calculation. If there is gas at the edge of the plot, see our comparison of a heat pump vs a gas boiler. The gas pipe is connected by the gas service; we don't touch it.

A 5 kW rooftop solar system costs from 15,600 ₾. Batumi has more overcast days than eastern Georgia, so the same system produces less energy here. On the other hand, peak output in summer comes during the hours when the air conditioners are running. We prepare the roof for the system in advance: the pitch, embedded fixings for the mounting, a place for the inverter and the cable route. Surplus power can be exported to the grid under the microgeneration rules. The way exported energy is paid for at new installations is changing, so we check the terms with the distribution company under the rules in force in 2026, and again before connection.

When energy efficiency pays off

We calculate the savings for your design at current tariffs, and the set of measures depends on how the house will be lived in:

For a house lived in all year round we design the full set from the start. Energy efficiency is cheapest at the concept stage: the shape of the house, the orientation of the windows and the overhangs cost almost nothing then, while correcting them in a finished house is expensive.

How we check the result

We check airtightness with a test: the house is closed up, a fan in the doorway creates a pressure difference, and an instrument shows how much air leaks through the gaps. We do it before the finishing, while the membranes and joints are still exposed and a gap can be taped up in minutes. On the same visit a thermal imaging camera shows the cold spots around the windows, roof and plinth. Thermal imaging needs a temperature difference, so the survey is best planned for the cooler season. The air tightness test and thermal imaging survey cost from 1,020 ₾.

How much an energy-efficient house in Batumi costs

The energy-efficient specification adds from 270 ₾ per m² to the price of a turnkey house. This extra covers thicker than usual wall and roof insulation, windows installed within the insulation layer, details without thermal bridges, and ventilation with heat recovery. The ventilation makes up a noticeable part of it: a heat recovery system for a 120–180 m² house costs from 17,400 ₾. A turnkey house built to this specification costs from 1,950 ₾ per m², and the heat pump and solar panels are priced as separate lines.

Large south- and west-facing windows, a complex shape with cantilevers and a house in the mountains push the price up. We send a preliminary estimate from the house plan and photos of the plot within 24 hours on business days; the final cost is set on the basis of the design, after a visit to the plot and once the estimate is agreed.