Bioclimatic design of a frame house:
how to make a frame house a passive climate regulator Automatic translate

Frame technology gives the designer rare freedom — to change wall thickness, roof shape, and opening placement without regard to the supporting masonry. This flexibility allows for bioclimatic principles to be incorporated into the design from the very beginning. A house designed with solar trajectory, wind patterns, and site topography in mind consumes less energy for heating and cooling. At the same time, it remains comfortable year-round — without the need for complex engineering systems.

What does the word "bioclimatics" mean?

Bioclimatic design is a method in which a building is adapted to the local climate from the design stage. The architect considers three key factors: solar radiation, wind, and temperature fluctuations. The goal is to utilize the site’s natural resources in a way that reduces dependence on mechanical heating and air conditioning.

A frame structure is more suitable for this than many others. The walls here are a "sandwich" of studs, insulation, and sheathing. They can be thicker on the north side and thinner on the south, where the sun compensates for heat loss. Window openings can be offset, the roof pitch can be changed, a buffer zone can be added — all without recalculating the load-bearing capacity of the brickwork or concrete walls. A frame "forgives" asymmetry, and asymmetry is the basis of the bioclimatic approach.

Orientation to the cardinal points

The house’s location on the site is the first and most cost-effective design decision. The southern façade receives maximum solar energy in winter, when the sun is low on the horizon. Panoramic glazing on the southern wall, 6-8 m² in area, can provide up to 15-20% of the total heating needs for a house of approximately 120 m². The northern wall, on the other hand, should be as solid as possible, with a minimum of windows and an increased insulation layer — 200-250 mm instead of the standard 150 mm.

The east and west sides require special attention. Morning sun from the east is beneficial — it warms the house after it cools overnight. Conversely, western sun in summer overheats the rooms. Small windows, external blinds, or planting deciduous trees that provide shade in the summer and let in light in the winter can help.

A common mistake is turning the house "in the direction of the road" rather than toward the cardinal directions. In practice, even a 30° tilt of the façade from the south reduces solar energy gain by 15-20%. For a frame house, where the thermal capacity of the walls is low, this is a significant loss.

Roof shape and overhangs

In a bioclimatic project, a roof is more than just a protection from precipitation. The pitch and length of the overhangs determine how much sun reaches the south wall at different times of the year.

In winter, the sun in temperate climates rises to 11–18° above the horizon. In summer, it rises to 55–62°. A 600–800 mm overhang over a south-facing window will allow low winter rays into the room and block the high summer sun. This technique is called a "passive sunshade." It costs virtually nothing and eliminates the need for an air conditioner in July.

A north-facing mono-pitched roof is another bioclimatic solution. The south wall is higher, with a larger glazed area. The north-facing slope sheds snow and rain, while reducing heat loss through the roof. A frame structure allows this type of roof to be implemented without complicating the rafter system — studs of varying heights on opposite walls are sufficient.

Natural ventilation through the frame

Frame houses require a well-thought-out ventilation system. A sealed wall "pie," while excellent at retaining heat, simultaneously blocks natural airflow. A bioclimatic approach solves this problem without forced ventilation — or, more accurately, minimizes it.

The principle is simple: air enters through supply valves on the windward side of the house, passes through the rooms, and exits through exhaust ducts on the leeward side or at the roof ridge. The pressure difference between the windward and leeward facades creates a draft that operates without electricity. To determine the windward side, the wind rose for a specific area is analyzed — this data is publicly available on meteorological service websites.

A frame wall is convenient because ventilation ducts can be installed inside it without losing usable space. The space between the studs is a ready-made "shaft" with a cross-section of 50 x 150 mm or more. The vertical ducts in the walls are connected to the horizontal ducts in the floors, resulting in a system hidden within the structure.

In addition, the supply and exhaust vents should be equipped with adjustable dampers. In winter, excess air exchange increases heat loss, so it is limited to the sanitary standard — approximately 30 m³/h per person. In summer, the dampers are fully opened, allowing the house to breathe thanks to the wind.

Thermal inertia and methods of its compensation

The main feature of a frame wall is its low thermal capacity. It warms up quickly, but cools down just as quickly. A brick or concrete house accumulates heat during the day and releases it at night. A frame wall lacks this.

There are several ways to compensate for the lack of thermal mass. The first is a concrete floor screed 80–100 mm thick. It acts as a heat accumulator, absorbing heat from sunlight through south-facing windows during the day and slowly releasing it in the evening. The mass of such a screed for a 100 m² house is approximately 18–20 tons — enough to smooth out daily temperature fluctuations by 3–5°C.

The second method involves internal partitions made of heavy materials. A 120 mm thick brick wall between rooms adds thermal capacity without compromising the frame structure. The partition doesn’t bear the roof load — it simply "fills" the space within the frame.

The third option is a recuperator. This is a device that transfers heat from exhaust air to supply air. Modern plate recuperators are 85–90% efficient. Installing a recuperator reduces ventilation losses by almost half, making a frame house comparable in energy efficiency to a masonry home.

Calculating savings in practice

Abstract percentages are hardly convincing. Let’s look at a concrete example: a single-story frame house with an area of 120 m² in a climate zone with a 5,000 degree-day heating season (roughly the latitude of Moscow or Kazan).

A standard project without bioclimatic adjustments consumes approximately 120–140 kWh per square meter per heating season. Annual heating costs for gas, at a rate of approximately 8 rubles per cubic meter, will be approximately 45,000–55,000 rubles.

A bioclimatic design for the same house with south-facing glazing, optimal overhangs, a concrete screed, and a heat recovery unit shows energy consumption at 70–85 kWh/m². Savings are approximately 35–40% annually, or 18,000–22,000 rubles. Over ten years, this adds up to a cost comparable to the cost of the foundation itself.

Additional costs for bioclimatic solutions during construction are minimal. Orienting the house costs nothing — it just requires a competent designer. Adding more insulation to the north wall adds 15,000–20,000 rubles. A concrete screed instead of a wooden floor adds approximately 80,000–100,000 rubles for a 120 m² house. A heat recovery unit costs 35,000–60,000 rubles. The total additional investment is 130,000–180,000 rubles, which pays for itself in 7–9 years on heating alone, not counting savings on air conditioning in the summer.

Microclimate of the site

Each site has its own climate characteristics, differing from the regional average. The lowland collects cold air in winter and can be 3–5°C cooler than the hilltop on a calm night. The forest strip to the north acts as a windbreak, reducing heat loss through the walls by 10–15%. A pond near the house moderates temperature peaks, cooling the air in the summer and slightly warming it in the fall.

Before designing, it’s helpful to conduct at least some amateur measurements: install a thermometer at several points on the site, track wind direction in different seasons, and determine shade zones from neighboring buildings and trees. This data, superimposed on the site plan, provides the designer with information that’s impossible to obtain from building codes and climate reference books.

Frame technology allows for targeted solutions to such nuances. A corner area that is more exposed to drafts can be reinforced with an additional layer of windproof board. The wall facing the open field can be insulated by 50 mm more. A window facing a neighbor’s fence three meters away can be reduced in size, and the savings can be used to increase the southern glazing.

Advertising Karkasnik LLC TIN 5313015692 ERID 2VtzqxgjwT3