AAC Block or Brick? Wall Choice in Hot Climates

Short answer: In the question of AAC block or brick, AAC block stands out in terms of thermal insulation: thanks to its porous structure, it conducts less heat than conventional perforated brick of the same thickness and is lighter. However, the insulation advantage of AAC block decreases as it becomes damp; a study conducted at Kırıkkale University shows that thermal conductivity increases significantly as the moisture rate rises. In Cyprus’s humid coastal climate, the right plaster, waterproofing and detail workmanship are as important as the choice of material.

This article has been prepared for buyers who want to understand the wall material in the technical specification when purchasing a home off-plan in Northern Cyprus (TRNC), those considering building a villa, and homeowners planning insulation improvements in their existing home. The structural system and earthquake safety are a separate topic; you can find the basic principles in our article what should an earthquake-resistant building be like.

What does an infill wall do?

In a reinforced concrete building, the loads are carried by columns, beams, shear walls and slabs. Walls built with AAC block, brick or pumice block are mostly non-load-bearing infill walls: they divide the space, create a shell between the outdoor and indoor environments, and determine heat, sound and moisture behavior. Therefore, the choice of wall material affects not the load-bearing capacity of the structure directly, but its comfort, energy consumption and long-term maintenance needs.

In a climate like Cyprus, where summers are long and hot and coastal areas are humid, the external wall has two roles: to delay the transfer indoors of the heat loaded onto the wall by the sun in summer, and to prevent condensation on the inner surface in winter. This is achieved not by the material alone, but by the system created together by the material, insulation, plaster and details.

AAC block or brick: comparison table

Before deciding between AAC block and brick, it is useful to look at the general characteristics of three common wall materials. Since values vary by manufacturer, density class and block thickness, an accurate comparison should be made using the product’s technical data sheet and declaration of performance.

To give an example for the information in the fire row, the product page of Turkish AAC block manufacturer KÇS defines AAC blocks as A1 non-combustible class. Such declarations should be confirmed from the product’s current declaration of performance (DoP).

The pumice block in the table is produced by mixing pumice, a lightweight aggregate of volcanic origin, with cement and moulding it. It is heavier than AAC block, generally lighter than conventional perforated brick, and its insulation performance varies according to the aggregate and void structure. Whichever material is selected, the product’s density class, declared thermal conductivity value and recommended mortar-plaster system should be clearly stated in the technical data sheet. The fact that the material name is the same does not mean that two products deliver the same performance.

How does moisture affect AAC block insulation?

The strongest aspect of AAC block is thermal insulation; its most sensitive aspect is moisture. In a study carried out at Kırıkkale University on G2/04 class AAC block, thermal conductivity was measured within a temperature range of 0–45 °C and a moisture range of 0–41,5 percent. According to the study’s regression model, thermal conductivity, which is approximately 0,093 W/mK in dry and cold conditions, increases as both temperature and moisture rise, with moisture having the greatest effect.

The practical meaning of this is as follows: an AAC block wall into which rainwater has penetrated, or which has cracked plaster or has been covered with unsuitable plaster, cannot achieve the insulation value stated on paper. In Cyprus, winter rains can be short but intense; summer humidity is also high in coastal areas. For this reason, the following details are important:

• Suitable plaster: The primer and plaster system recommended by the manufacturer should be applied to the AAC block surface; hard plasters with a very high cement ratio may be prone to cracking.
• Window and slab junctions: The areas around joinery, column-beam junctions and parapets are the most critical points in terms of waterproofing.
• Ground contact: On ground floors, an insulation layer should be present to prevent the wall from drawing moisture from the ground.
• Protection on site: Blocks that have been exposed to rain for a long time during construction should not be plastered while damp.

These points apply not only to AAC block but to all wall materials; however, their effect on insulation performance is more pronounced in AAC block. We have also covered materials and maintenance in coastal buildings in our coastal durability and maintenance guide.

Thermal bridges and external insulation

No matter how good the wall material is, reinforced concrete columns and beams conduct much more heat than the wall. These points are called thermal bridges. This is why, on a sun-exposed façade in summer, the inner surface is warmer along the line of the beam, while in winter it is colder and mould appears along that line.

The most effective way to solve thermal bridges is to cover the exterior of the building with a continuous insulation layer. In this method, commonly known as external insulation, insulation boards are bonded and anchored to the façade, and mesh and thin plaster are applied over them. In Cyprus, external insulation is expected not only to work in winter, but also to reduce the air-conditioning load in summer by delaying the transfer indoors of the heat loaded onto the wall by the sun.

A surface as important as the wall is the roof and the top-floor slab. In Cyprus, the summer sun strikes horizontal surfaces for the longest time; an uninsulated terrace roof can heat the apartment below it much more than the walls. For this reason, when buying a top-floor or penthouse apartment, it is also necessary to ask about the details of roof thermal insulation and waterproofing, in addition to the external wall material.

External insulation in an existing apartment building is a decision that concerns the entire building. According to the Condominium Ownership and Construction Servitude Law, upon the request of one of the condominium owners, thermal insulation can be carried out in accordance with the relevant legislation by a decision taken by the majority of condominium owners in number and land share. Having only the external wall of your own apartment covered is generally not possible due to façade integrity and common area rules. We explained how the condominium owners’ board works in our article on construction servitude and condominium ownership.

Sound insulation: walls between apartments are a separate topic

There is no rule that a material with good thermal insulation will also be good in sound insulation. Sound is largely blocked by mass; the lightness of AAC block is an advantage in terms of heat, but a limiting factor in terms of sound. Therefore, in walls separating two apartments, it is necessary to look not only at the block type, but also at the total thickness of the wall, the plaster on both faces, and, if necessary, the sound insulation layer added between them.

In holiday complexes, neighbouring apartments being occupied in summer and empty in winter causes the sound issue to be noticed in the first summer. Before purchasing, listening to the voice of someone speaking in the next room in a show apartment or during a live viewing is a simple but instructive test. Socket boxes placed back to back between two apartments are also one of the weak points through which sound passes; you can ask how this detail is resolved in the technical specification.

What should a buyer ask in a new project?

Sales brochures rarely describe wall materials in detail. When buying a home off-plan, ask for the following information to be included in the technical specification in writing:

1. External wall material and thickness: AAC block, brick or pumice block; block thickness and density class, if any.
2. Façade insulation: Whether external insulation is applied, and the type and thickness of the insulation material.
3. Roof and terrace insulation: Details of thermal insulation and waterproofing on top floors and roof levels.
4. Plaster system: Primer and plaster suitable for the material used.
5. Internal partition walls: Thickness or additional layer for sound insulation in walls between apartments.
6. Warranty: Whether façade cracks and moisture problems are covered by the warranty.

A contractor who can give clear and written answers to these questions is generally also careful in site management. We have compiled other criteria to consider when choosing a company in our guide to choosing a reliable construction company in Cyprus. To evaluate energy performance as a whole at villa scale, you can also review our villa energy and water efficiency inspection guide.

Frequently asked questions

Is an AAC block house earthquake-resistant?

In reinforced concrete buildings, earthquake resistance is determined by the structural system, namely the columns, beams, shear walls and foundation; AAC block is generally used as a non-load-bearing infill wall. Being lightweight reduces the total weight of the building, but earthquake safety is understood not from the name of the material, but from the project’s compliance with regulations and the quality of workmanship.

Does AAC block cause damp?

AAC block does not produce moisture by itself, but it can absorb water due to its porous structure. If rainwater penetrates the wall through plaster cracks or faulty details, both the insulation value decreases and moisture stains may appear on the inner surface. With the plaster system recommended by the manufacturer and correct waterproofing details, this risk is largely prevented.

Is a brick house or an AAC block house cooler?

When compared at the same thickness and without insulation, an AAC block wall heats the interior less in summer because it conducts less heat. However, the wall is not the only factor determining coolness; façade orientation, glass ratio, external shading, roof insulation and external insulation often make a greater difference.

Is external insulation necessary in Cyprus?

Its obligation varies according to the project and legislation, but it is also beneficial in hot climates. Insulation that continuously wraps the façade cuts thermal bridges at columns and beams, reduces the air-conditioning load in summer and the risk of condensation in winter. In existing apartment buildings, the decision is taken by the majority of condominium owners in number and land share.

Can heavy items be hung on an AAC block wall?

They can be hung, but special anchors suitable for AAC block should be used. Standard plastic anchors may not provide sufficient grip in a soft and porous structure. For heavy kitchen cabinets, a TV bracket or an air-conditioner indoor unit, use the fasteners recommended by the manufacturer and pay attention to the load limit.

If you would like to review the wall and insulation details of a property you are considering purchasing together through the technical specification, you can contact the Akol Global team.

This article is for informational purposes only; it does not replace legal, tax or financial advice. Last updated: October 2026.