ARCHITECTURAL DESIGN COMPETITION

FOR PASSIVE HOUSE IN BULGARIA

Dionisis Gonatas Dipl. Arch. Vangelis Lantavos Dipl. Arch.

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Building-Metric-Sheet-26.xls


Architects: Dionysis Gonatas, Vangelis Lantavos
Mechanical engineer: Evi Tavlaki
Location: Lozen, Municipality of Stolichna, Bulgaria
Site area: 1546,17 sqm
Building area: 170,09 sqm

The house is conceived as an a composition of two parallelepiped volumes, with one placed vertically above the other, forming an
asymmetrical ‘T’ shape. The resulted building shape, creates a protected external decking space for leisure and various activities mainly during
spring and summer period. This serves as a transition space from the inside to the garden. Although the given plot of the competition is
virtual, according to our view, the building should be placed in a retreat from the street reducing all noises and disturbance. Therefore, this part,
is protected by the house’s volume and becomes a very quiet part of the property.
The ground floor of the building has been positioned in parallel with the road and as a result only two openings, including the
main entrance, are placed in this side. This space accommodates the living and dining area, kitchen and auxiliary rooms which
defuse in the external decking. Storage and electromechanical facilities room is also found on the same level. Between the two, a covered
terrace is formed which can be used in different ways.
The first floor consist of three bedrooms and a bathroom connected with a long south west oriented corridor with views towards the vicinity. Additionally, opposite the staircase there is access to the planted roof above the living-dining area. The two previous described volumes that compose the dwelling have different external appearance, with that of the ground floor, be covered with a whitish elastomeric plaster coating, while on first floor the façades are covered with wooden strips of cedar, both retaining the traditional architectural morphology of the area.

Construction:
The building is constructed of HEA steel columns and beams (181X171mm, 160x152mm) anchored with high strength holding down
bolts on reinforced concrete insulated foundations. The external walls are of wooden vertical studs (100X50mm) that have been gladded with 19mm OSB-B panels for external use, while the internal perimeter of the walls is constructed with drywall system of 12,5mm plasterboards on metal studs as well as all internal walls and ceilings. The of the wall is filled with 220mm, in total, high performance mineral wool insulation panels and sealed with airtight membrane in order to prevent moist indoor air from leaking through cracks. These cracks would permit the air to cool down, making the humidity in the air condense  and putting the building at risk of becoming moist and growing mould.
The 120mm thickness first floor slab is constructed of reinforced concrete on a permanent formwork. The free cantilevered balcony uses a load
bearing insulation element with a thickness of 120mm for avoiding thermal bridges and meeting with the required standards.
High quality wood-aluminum window frames with U value around 0,65 W/m²K have been used as these are essential components for a Passive House. The South-West and South-East oriented windows of the house also function as ‘passive’ solar panels that let the energy of the sun into the spaces. Triple low-e glazing and the insulated window frame are required for the climatic zone of Lozen. The roof is covered with re-used tiles that create a bond with local buildings and preserve traditional aesthetics and values. The outdoor deck space is constructed with synthetic wood strips on 50X50mm galvanized metal beams forming a grid and is able to withstand hard use and moisture.

Sustainability:
The bioclimatic design of the house aims to ensure acceptable and balanced indoor conditions all around the year in order to reduce energy  consumption, with all the benefits that this means, economically, environmentally by reducing carbon dioxide emissions, quality of life. The orientation of the building as well its design is done in such a way the most of openings face South-West and South-East, while the  Northern side, that is affected by cold winds during winter, has only two openings.
The installation of photovoltaic panels (up to 90 sqm) on the roof producing power of 6 KW is optional and can be used for electricity purposes and hot water. Also there is a capability of charging hybrid vehicles through the system. The planting of the terrace above living-dining area (37 sqm) substitutes at a higher level the green surface removed from the ground, and enhances the thermal and acoustic insulation of the roof. Plants
naturally filter the dust and moisture regulating the microclimate. In case of heavy rainfall, green roof retains 70-90% of the water and
delaying its runoff. The vegetation system is light (50-100kgr/m²) and needs minimal maintenance. Furthermore the construction of an underground concrete tank that collects and reuses rain water for irrigation of the garden, in cisterns and washing machines presents additional environmental benefits. The soft water prolongs the life of devices and reduce cleaning products use.

Ventilation system:
In the house the ventilation system plays an important role, providing clean, pollen free, dust free air and eliminates moisture and odors
where they occur. Depending on the efficiency of the heat exchanger, over 90% of the heat from the exhaust air can be passed on, which brings the incoming air almost up to room temperature. A high quality system use much less energy than the amount they are able to save by preventing heat loss. The basic principal of the house ventilation system is that moist air is extracted from the kitchen, bathroom, WC, while fresh air flows into the
living areas. As a result, the hallways are automatically ventilated as well. The heating demand of the house is covered by the energy fireplace, located in the living room, which warms the air and then distributed it through the ventilation system to all other rooms.