House extension in Batumi: foundation, joint, opening, roof, permit

House extension in Batumi: more floor area without a new storey

A house extension in Batumi gives a room, a kitchen, an enclosed terrace or a garage next to the house and puts almost no load on the old walls. It is a good option when the house foundation is too weak for an extra storey and there is space on the plot allowing for setbacks from the neighbours. The main difficulty of an extension is the junction: the new part settles differently from the old house, and if they are rigidly tied together, cracks will run along the joint and water will leak into it.

Its own foundation and a joint

We almost always place an extension on its own foundation and separate it from the house with a movement joint. That way the new part can settle in its own way, and in an earthquake the two buildings do not hit each other. We close the joint with flexible materials outside, on the roof and in the floor, so it cannot be seen and no water gets in. How a foundation is chosen for the soil is on the foundations page.

What to build from

For a living extension we usually choose the same technology as the house, so the walls, windows and facade look like one whole. Glazed extensions on an aluminium frame are described on the glass extension page. If you need a garage, see the garages page.

The way into the house

• an opening in a load-bearing wall is made only to calculation;
• temporary props go in before opening up;
• the opening is framed with a steel frame or a reinforced concrete lintel;
• the house services are extended into the extension;
• the extension floor is brought level with the house.

A new opening in a load-bearing wall weakens it, so the position and size are chosen by the structural engineer, not by the crew's convenience. If the wall is old and cracked, it is strengthened first.

Roof and water

The most vulnerable point of an extension is where its roof meets the house wall. Water from the large roof runs onto the small one, and in a downpour more water reaches the junction than you would think. We make the junction with a flashing tucked under the wall finish, the right fall and a separate gutter. The waterproofing of the extension foundation is joined to the house waterproofing; more on the waterproofing page.

Permit and setbacks

An extension increases the floor area and footprint of the house, so it usually needs a permit, and after construction it is registered. City Hall will check setbacks from the boundaries and the plot coverage ratio: on small plots an extension often runs into exactly these coefficients. If a terrace is just under a canopy without walls, the procedure can be simpler. An enclosed terrace or conservatory is also worth planning straight away; more on the houses with a terrace page.

How much an extension costs

A house extension in block or concrete without finishes costs from 1 110 ₾ per m². A turnkey glazed extension or conservatory on an aluminium frame from 2 580 ₾ per m², an opening in a load-bearing wall with a steel frame from 2 520 ₾. Strengthening the house strip foundation with a jacket from 660 ₾ per linear metre if needed at the junction, the extension design from 78 ₾ per m². The final cost is set after inspecting the house and plot and agreeing an estimate.