ARCHITECTURAL DESIGN COMPETITION

FOR PASSIVE HOUSE IN BULGARIA

John Read BA[Hons]

(182 - user rating)

Building-Metric-Sheet-16.xls

There are three basic principles to the design concept; simplicity, sustainability and the visual communication of the passive house principles.

Simplicity:
The house is firstly divided into two separate functions; living space and working space.
The working area is in turn split into its specific functions (kitchen, bathrooms, office, storage, hall and circulation).
The Living space by contrast is keep as open and as flexible as possible. The ground floor living area is a pure space dominated by the three large 'picture' windows that not only frame the outside but draw attention to themselves and therefore the special importance of windows in a Passive House.
The second floor living space is shown as an open space and sleeping area. The family space can be defined by the size of the family and their specific needs. It can be divided with additional walls at a later date and be left open during the first years of the children's life as a combined sleeping and play area.
The house stays closely within a classical ideal, but the design is reduced to its most basic and functional components. The kitchen and office space are placed at opposite ends of the building and both can be closed from the living space for practical reasons.
The entrance way opens directly to view through the house and its area is minimized to a long narrow space that serves its basic function but also provides additional circulation should the kitchen and office be closed.
Storage is a priority of the design. It is an essential part of any functional house and therefore is shown as literally an integral part of the wood construction. In addition to the ground extensive ground floor shelving the space under the stairs is also utilised. Both as desk space and general storage.
The exterior design emulates a child's drawing that has simply been taken to another level. Everything about it says 'house'. It is intentionally simplistic to communicate the idea that a passive house is simply a normal house that has been taken to the next level. There is nothing space-age about a passive house, it is simply everything we already know about efficiency carefully crafted into an effective combination of energy preservation. There for the house should be instantly recognisable as a family house.


Sustainability
The sustainability of the buildings materials are an integral part of the design.
A sustainable wood construction is used throughout the building . The use of common fast growing wood from carefully managed FSC forests is essential. The construction then locks in the carbon and can have an overall zero carbon footprint.
A combination of flat panel water heaters and PV cells can be used to provide the majority of the buildings hot water usage. Only a small system has been included in the design in an effort to minimise the overall cost.
Although real wool insulation would have been preferable from a sustainability viewpoint, mineral wool was chosen as a cost effective and durable alternative. Cellulose would also be a good choice but it is not as widely available and is slightly less cost effective than mineral wool.
The energy consumption during the life of the building is reduced by its compact form, optimal window to facade proportions of 28% glass to wall on the south face and much less on the other facades. Ensuring an optimal gains to losses ratio.
The internal construction is also a combination of cost-effective and sustainable materials. The flooring is made from sustainable white pine as are the West and East walls. The remaining walls are constructed from plaster to keep the cost reasonable.

Visual Communication of the Passive House Principles
The exterior shape of the building has been reduced to its most basic lines. The shape extenuates its compact and efficient form. The simplicity shows the basic principles of thermal bridge free design (nothing sticking in or out of the basic structure) and compact form (keeping surface area heat losses to a minimum).
The West and East exterior facades have a clear division of wood orientation. This corresponds to the exact position of the thermal envelope. Showing proudly the thickness of the external walls and demonstrating the importance of excellent thermal insulation and the air-tight principles.
Powerful sun-blinds on gliding bars can be moved over the windows during the hotter days of the year. Something that is often overlooked in passive house design is overheating. Traditional sun-blinds often lead to thermal bridges and/or accidental overheating due to the heat trapping effect of roller-blinds. Wood is more sustainable, is more effective at deflecting heat than metal or material and can become a seamless, thermal bridge free, part of the facade. Although made of the same material the sun-blinds hang freely in front of the windows to allow a sufficient air gap to allow heat venting between the window and the blind.
The interior of the house is designed to exaggerate the importance of the thermal shell. The wooden walls to the West and East echo the same thermal envelope principles as the external change in wood direction.
The main south windows are large and slightly raised from the ground. This creates a separation from the outside and shows the windows in their own importance. Unlike in many houses where they are intentionally invisible. In a Passive House they are one of the main tools. They are the one of the most important elements and therefore they area raised above the surroundings to show them as individual parts of a whole.
In addition to the framing of the windows this also creates a secondary benefit of a small seating area in front of each window. Unlike with normal windows, it is perfectly comfortable to sit under a passive house window all year round.
The ventilation unit is isolated away above the bathroom, it is an important element to the Passive House but can often become the reason to call any low energy house a Passive House. Therefore the decision was made to hide it away, allowing the other major elements of real passive houses to be shown in their own importance.
The choice to hide it a way is also to do with the reality of dampening the sound and hiding the machinery. Its position within the thermal envelope provide the optimum performance and its central location allows easy ventilation to all rooms below, minimising cost of components and maximising the efficiency and durability of the machinery.