Thermal & Waterproofing Insulation

## Why Thermal and Waterproofing Insulation Is the Most Important Investment for Your Building

According to data from the Sustainable Energy Development Agency (SEDA), over 90% of residential buildings in Bulgaria were constructed before 1990 and have an energy performance rating of E, F, or G. This translates to enormous thermal energy losses through walls, roofs, and foundations — and correspondingly disproportionate heating and cooling bills. At Trading Build Engineering, we view thermal and waterproofing insulation not as an expense, but as a strategic investment that increases property value, improves comfort, and significantly reduces operational costs.

### External Thermal Insulation Systems (ETICS)

Our primary method is the External Thermal Insulation Composite System (ETICS), known in Bulgaria as the "contact system" (контактна система). This system includes several material options tailored to the specific needs of each project:

**Expanded Polystyrene (EPS)** — The most widely used solution for residential buildings. We offer EPS with thicknesses ranging from 8 to 20 cm and a thermal conductivity coefficient of λ = 0.035–0.040 W/mK. Suitable for facades, ceilings, and floors, EPS offers an excellent quality-to-price ratio that makes it the go-to choice for most residential insulation projects.

**Extruded Polystyrene (XPS)** — With higher density and zero water absorption, XPS is ideal for plinths, foundations, and below-grade building elements where contact with ground moisture is constant. Thermal conductivity: λ = 0.030–0.036 W/mK.

**Mineral (Stone) Wool** — The preferred solution for buildings with enhanced fire safety and sound insulation requirements. With a fire reaction class of A1 (non-combustible), stone wool is mandatory for buildings over 28 meters in height under Bulgarian building regulations. It provides excellent vapor permeability, allowing walls to "breathe." Thermal conductivity: λ = 0.035–0.042 W/mK.

**Graphite-Enhanced EPS (Neopor / Grey EPS)** — An advanced version of standard EPS with graphite additives that improve insulation performance by up to 20%. At the same thickness, it achieves significantly better results — λ = 0.031–0.032 W/mK. We recommend it for projects where limited space demands maximum efficiency at minimum thickness.

### The ETICS Installation Process

Installation follows a strict technological sequence: 1. Surface preparation — cleaning, priming, and installation of the starter (plinth) profile 2. Adhesive bonding of insulation boards using cementitious adhesive 3. Mechanical anchoring with expansion dowels (minimum 6 per m²) 4. Reinforcement layer — fiberglass mesh embedded in adhesive basecoat 5. Primer coat to improve adhesion 6. Finishing decorative render — silicone, silicate, or mineral-based

### Waterproofing Solutions

Water is the most dangerous enemy of any structure. We offer a full range of waterproofing solutions designed for specific applications:

**Foundation and Below-Grade Waterproofing** — We use bituminous membranes, polymer-based waterproofing systems, and drainage solutions for comprehensive protection of underground structures. Our approach involves a two-layer system with both mechanical and thermal bonding.

**Flat Roof Waterproofing** — Two-component polyurethane coatings, TPO and PVC membranes, and bituminous roll waterproofing. We create seamless, elastic coatings that withstand temperature fluctuations from -30°C to +80°C.

**Terrace and Balcony Waterproofing** — Polyurethane and polyurea coatings with excellent elasticity (elongation of 100–500%), UV resistance, and the ability to receive flooring directly on top.

**Bathroom and Wet Room Waterproofing** — Single-component and two-component cementitious waterproofing, liquid membranes, and waterproofing tapes for critical zones around drains, pipes, and corners.

### Energy Efficiency and Energy Performance Certificates (EPC)

Under Bulgaria's Energy Efficiency Act and Ordinance No. 7, every new and substantially renovated building must hold an Energy Performance Certificate (EPC). Our insulation solutions are designed to achieve a minimum energy rating of Class B, and with comprehensive renovation, Class A.

Since 2021, EU Directive 2018/844 requires all new buildings to be "nearly zero-energy buildings" (nZEB). We work in close collaboration with certified energy auditors to ensure our projects meet these stringent requirements. For homeowners, this means not just lower bills, but a future-proof property that complies with increasingly strict European energy standards.

### Government Subsidy Programs for Insulation

Bulgaria offers several funding mechanisms for thermal insulation projects that can dramatically reduce or even eliminate out-of-pocket costs:

• **National Program for Energy Efficiency of Multi-Family Residential Buildings** — grant funding covering up to 100% of eligible costs for facade insulation, roof insulation, and replacement of windows and doors. - **National Recovery and Resilience Plan** — EU-funded grants for energy class improvement by a minimum of two classes. - **Operational Programme "Development of the Regions"** — subsidies for comprehensive residential building renovation.

Our team assists clients with preparation of all required documentation — energy audits, technical building passports, and investment projects — for applications under these programs.

### Return on Investment (ROI)

Based on our experience with over 150 completed projects, the average reduction in heating costs after comprehensive thermal insulation is 45–60%. With an average investment of €25–40/m² for an EPS system and €40–60/m² for mineral wool, the payback period ranges from 3 to 7 years depending on building type and existing condition. After the investment is recouped, the savings continue for the entire remaining life of the system — a minimum of 25 years.

Additionally, quality insulation increases the market value of a property by 10–15% and significantly improves the energy certificate rating, which is an increasingly important factor in property sales and rentals across the Bulgarian real estate market. With energy costs in Bulgaria rising year over year and EU regulations growing stricter, the question is no longer whether to insulate, but how soon you can begin.