Eco machiya(tranditional house)

Background:

Kyo-machiya is literally an urban living space that still exists mainly in Kyoto.

This is a typical example of a Machiya townhouse scattered throughout the country.

That creates a gap in Kyoto's lifestyle, space, and urban development, in which work and home coexist.

It is changing as the times change.

On top of that, as shown in the diagram below, Kyoto Machiya and the city planning of Kyoto are closely related, and the structure evolved from blocks in the original grid to units of blocks across the road, forming a community known as a two-sided town based on a system of coexistence and mutual protection.

There are several typical examples of existing Kyoto Machiya, among which, the street garden style Machiya is said to be the most familiar type to us, and long-standing machiya research has shown that it has seven floor plans, which the Kyoto City Landscape and Urban Development Center (Machisen) which has been carrying out this project, introduces in its report published in 2019 titled as the world of Kyoto-Machiya that Kyoto people don't know*1.

Also, among the seven patterns, there is especially a two-story, one-row, three-room floor plan pattern in which three rooms are along the street garden (upper open atrium) and three rooms are placed on the second floor. accounts for about half of the total. *2

*1, *2

Kyoto Landscape and Urban Development Center, edited by Osamu Oba, 2019 “Kyoto Machiya Chart” reveals the world of Kyoto Machiya that Kyoto people don’t know

Attempt:

This project is to renovate a typical townhouse called Nagaya (one row, three rooms) in Hiyoshi-cho, Kyoto as a reference project, and as well as to reconsider of the characteristics of today's townhouses which are uninterrupted,

the aim is to improve disadvantages or inconveniences of the characteristics of today's townhouses through modern methods.

Issues appealed:

1)Restore the design of townhouses as much as possible to sustain the landscape and urban culture.

2)Attempt to turn "NO" into "YES" by ensuring the privacy, a good thermal environment, brightness, lightness, compactness, spaciousness and the appropriate soundproofing (sound insulation/absorption) compartments and spatial layout resolving the modern problems detailed in Machiya townhouses being renovated, such as hotness and coldness, darkness, narrowness, and lack of privacy through uses of modern methods.

3) Design a wooden/timber/woody building that incorporates old materials and unique furniture, fixtures, and features particular to traditional Japanese houses, and Kyoto.

4) Plan the structure with the combination of conventional framework construction methods and traditional construction methods.

Exterior views

Exterior view:

・It was considered that the formation of the landscape along with the neighboring townhouses was made through the arrangement of as many of the ``formal designs'' of Kyoto townhouses as possible in a modern manner.

・Skylights and ventilation towers placed on the roof are hidden from the road and well within the diagonal height restriction line limits, allowing constant natural lights into interior spaces and greatly contributing to natural ventilation (temperature difference ventilation).  In addition, all rooftops have risings of 200 mm or more, which significantly reduces water leakage and makes maintenance easier.

The front entrance has a lattice door, which is typical of townhouses, and covers a wide frontage.

・Inuyarai(Bamboo palisade) protects bay windows from flying water (Rainwater).

・Considerations have been taken to the landscape through the use of Manju tiles(Sweet bun), which are unique to Kyomachiya, for the roof tiles of the eaves and soffits.

・The north side of the Machiya townhouse was expanded by dedicating part of the original backyard area to a bathroom and washroom.

In addition, by adding a strong Japanese-style eave in front of the dining room on the north side of the first floor, it was intended to prevent rainwater from flowing in from the single-sided roof of the extension mentioned above, as well as preventing northerly winds from blowing in the winter.

Galvanium steel plates were used for both the eaves mentioned above and the single-slope roof of the extension, distinguishing them from the ``ichimonji tiles'' and ``manju tiles'' of the existing roofs renovated, giving them a sense of the times.

In addition, the boundary wall and exterior of the backyard were unified with grilled woods.

 ・The backyard garden is equipped with paving stones, pebbles, lawns, plants, external lighting, and the crafts made in Kyoto.

Interior views

・Whereas the finishes became traditional, made of the woods with the use of plasters and decorative plywoods for the ceiling, each component was insulated and sound-insulating sheets were installed near the noise source. By doing that, user comfort in the interior space is to be increased and the occurrence of sick building syndrome is to be prevented.

・The existing firebox + atrium, the new staircase and the atrium above it are connected to the roof-mounted skylight and ventilation tower at the top, allowing temperature difference ventilation, cross ventilation (including night purge), and natural lighting into the interior of the house.

・An attic storage room with a CH of 1.4 m or less and a floor area of 1/2 or less that of the floor just below (limited to non-residential use) is planned and vertical piping/wiring and ducts etc are placed in the atrium or on the wall, and cross-flow equipment piping and wiring ducts are placed under the floor or in the ceiling with the effective use of the original high floor height.

・The bathroom is assumed to be a system bath.

・ Roof insulation, underfloor waterproofing (Waterproofing sheets and Concrete waterproofing).

・Equipment piping installed behind the ceiling.

・Window glass is multi-layered to improve the insulation of the opening.

・Energy consumption of building equipment is reduced through the use of highly efficient air conditioning and water heaters (EcoCute or Ene-Farm).

・In the backyard, a drying rack is placed near the washing machine.

・The toilet is located in the space beneath the newly constructed stairs.

・The interior openings are equipped with fixtures which are characteristic of traditional houses, such as shoji screens, sliding doors, noren curtains, and latticework.

Structural diagrams

・The structure consists of the reinforcement with earthquake resistance, seismic control, and seismic isolation following traditional framework construction methods

Ex.Use of earthquake-resistant walls, braces, and hardware (earthquake-proofing), and damping and surface seismic devices.

・For wooden frameworks, at the time of renovation or new build, as many old materials as posible are reused with the measurements of connection and attachment.

Carbon solidification and absorption of the wooden materials used greatly reduce carbon dioxide (CO2) emissions throughout the life cycle of development, operation, and disposal, thereby contributing to decarbonization.

・The pillars and beams are 240mmx120mm, and the rest of the frames is 150mmx120mm, 120mmx120mm, and the joists and rafters are made of square timbers of 105mm to 40mm.

The above will be confirmed through structural calculations in actual projects.

・Basically, with the use of usable structural woods (old wood) and jointed woods,the wood frames are exposed and maintenance is made easier through the timber frame method.

・Thermal insulation, waterproofing, and sound insulation sheets will be placed inside the timber frame wall (sandwiched between the wooden framework) as infill.

・At the foundation, foot reinforcements are used to connect each pillar to reduce the shaking of the entire building.

*In actual projects, a structural plan/design based on project-specific constraints and a structural model based on structural calculations will be presented.

・In order to overcome the circumstances such as the stone-topped foundation or no foundation, which is a characteristic of townhouses, the foundations are reinforced with RC (reinforced with cobblestones).

・Reference standard type (Joist construction method) *There are various construction methods (e.g. hard floor construction method) depending on the contractor. Thus, the actual construction method used will vary depending on the project.

・As variants of the dormers and overhanging roofs, skylights and ventilation towers on the roof are placed with a rising edge to create a structure that is resistant to deterioration caused by rain and wind, and is a countermeasure against conventional rain leaks.

Environmental and energy diagrams

Newly installed eaves on the north side: contribute to sheltering from the rains, the north winds, and the rainwaters from the newly built bathroom/washroom roof.

Rooms on the north side: Lighted by the constant indirect light from the north side.

Skylight: Reduction of the darkness in the interior space of a townhouse.

Stucco walls: White walls diffuse the natural lights from skylights and brighten interior spaces.

24-hour class 3 ventilation: Placed in the toilet and kitchen.

Class 1 ventilation: Air supply vents: Windows, 24H air supply vents placed in each room.

Ventilation vents: Ventilation towers in the roof, windows, openings in internal partitions like shoji screens etc.

Cross ventilation and displacement ventilation: Achieved by providing a skylight and ventilation tower above the stairway area, the firebox, and the atrium.

Roof & lattice with south eave/soffit:

Summer: Functions as a sunshade by blocking direct sunlight.

Winter: Weak light enters deeply into rooms from the south opening, contributing to natural lighting, increasing the thermal mass of the earthen walls, and keeping the townhouse warm through insulation. (the amount of sunlight shielded from the grid, TBC) 

Ventilation tower & night purge: In the summer, the ventilation tower has not only a ventilation function but also a night air cooling one by blowing cold air throughout the townhouse at night. Also, instead of using a wall-type air supply vent, nighttime air supply is allowed to be blown throughout the room. 

After with a simple calculation sheet for detached houses, its outer shell performance during the basic design stage was verified, a Machiya townhouse with a high energy-saving performance (thermal insulation and airtightness) was planned with the design value of 0.4 which is not only below the energy-saving standard value (0.87), but also lower than the ZEH value (0.6) , the average solar heat gain rate during the cooling season (2.0) which is also lower than the standard value (2.8), and the average solar heat gain rate (2.1) during the heating season.

Overall, with the use of a large amount of the building materials such as the woods and natural materials, the positive effects about improvement of the health and immunity, warm and humid effects, and visual senses (ease, warmth, etc.) and the olfactory senses (relaxation, stress relief, etc.) are being demonstrated together with improvement of the internal air quality (IAQ).