"Blurred Envelop" - Home for Mr. & Mrs. Bandara

  • Building Type : Isolated or semi-detached house
  • Construction Year : 2017
  • Delivery year : 2020
  • Address 1 - street : Malwatta 70160 GODAKAWELA, Sri Lanka
  • Climate zone : [Af] Tropical Wet. No dry season.

  • Net Floor Area : 962 m2
  • Construction/refurbishment cost : 455 000 €
  • Number of Dwelling : 1 Dwelling
  • Cost/m2 : 472.97 €/m2
  • Primary energy need
    1.45 kWhpe/m2.year
    (Calculation method : Other )
Energy consumption
Economical buildingBuilding
< 50A
51 à 90B
91 à 150C
151 à 230D
231 à 330E
331 à 450F
> 450G
Energy-intensive building

The home for Mr & Mrs. Bandara is conceptualised as an interpretation of the "Walauwa" or Manor house of vernacular tradition, in Sri Lanka. The Walauwa signifies and announces the status of a member of the community. It becomes a focus of activity that brings together people of various strata of the community, albeit in harmony. 

Mr. Bandara is a self-made entrepreneur, who is now the head of a successful dairy based business, that reaches all over Sri Lanka. Yet, as was with people of old, in rural Sri Lanka, the Bandaras are well grounded in their approach to life, especially within the community and welcomed a 'Home' that allows them to connect and build relationships. 

The challenge was to interpret the scale and accessibility of a manor house, yet establish it as an exploration of contemporary architecture, that draws upon the uniqueness of the site and its users.   

The solution envisioned a "Blurred Envelop", that re-interprets the dominant roof of the tropical vernacular. An envelop that redefines the boundaries between roof and wall, to one that is neither wall nor roof. An envelop that shades - minimising solar heat gain; an envelop that screens and filters - allowing maximum ventilation together with ensuring privacy and security; an envelop that insulates - ensuring thermal comfort - yet welcomes the outdoors into its spaces; most importantly an envelop that creates 'places' - thus invite people to stay. 

The materiality of the envelop is especially important to form and space making. The heavy stone base with the terracotta tile 'umbrella' alternate emphasis - both internally and externally - creating distinct zones of activity and contemplation.

Photo credit

Archt. Pasindu Kithmina and Archt. Lahiru Wimalarathne


    Mr. and Mrs. Kapila Bandara - The Client


Construction Manager


    Structures calculist

    Eng. Keerthi Ratnayake



    Structural Design

    Construction company

    Saman Gamage


    General Contractor


    Archt. Shashikala Ranasinghe / Electroplastic Engineering Co.(PVT) LTD


    Lighting Consultant, Luminaire Design and Manufacture


    Mark Your Design | MYD - Shenuka Dias


    Furniture Design and Manufacture

    Other consultancy agency

    CQS Sunanda Gnanasiri


    Cost Consultant / Quantity Surveyor

    Other consultancy agency

    Eng. Kelum Perera and Eng. Rifai Mohamed

    kak.perera[a]gmail.com, rifaas[a]gmail.com

    M&E Engineering Consultants

Contracting method

General Contractor

Type of market


If you had to do it again?

A significant aspect of the building process was the time taken for construction. The extended time for the construction was due to the responsible and sustainable procurement of materials, and the human capital heavy building process. Yet, this is taken as a positive element in the overall scheme. This has allowed all concerned to make informed decisions and explore the labour intensive, hand-crafted approach to the creation of elements to the maximum.

Building users opinion

The well-defined functional zones, the careful detailing of each zone in continuous consultation with the User, has resulted in the Users being extremely happy with the product. The home has been in occupation for over a year - a year that has compelled extensive use of our homes because of the COVID19 pandemic – yet, the Bandaras remain content.

A conscious decision was taken to avoid air conditioning in occupied spaces. Even with the extended occupation of the spaces during this year, the thermal comfort, in particular, is deemed satisfactory. Thus, in post occupancy evaluation it was decided to maintain all spaces as free running.

The illumination levels were kept comparatively low, to imbue spaces with a quality that encourages people to stay. This aspect is highly appreciated, and the comfort and peace of the places created, is appreciated by the Users.

Mr. & Mrs. Bandara eagerly await the day they can share their home with their friends and relations, freely and safely – without concerns of COVID19.

Energy consumption

  • 1,45 kWhpe/m2.year
  • 15,00 kWhpe/m2.year
  • Other

Envelope performance

  • 1,41 W.m-2.K-1
  • The envelope is dominated by the terracotta tile skin. The roof and wall elements differ in their level of insulation and internal layer :
    The roof element includes a timber ceiling together with 50mm of insulation sandwiched between reflective layers.
    The wall elements act as screens, thus includes only the timber structure and tiles.
    The lower level of the residence uses random rubble walls. u-value = 4.38.

  • 0,24


    • No heating system
    • Solar Thermal
    • No cooling system
    • Natural ventilation
    • Solar photovoltaic
  • 88,70 %
  • No HVAC installed. Designed and run as a free running building. The spaces utilise ceiling mounted fans.

    The system uses Net-metering for the solar system. Thus, there is no credit granted for excess energy produced.

    The concept of the project is built around reducing solar heat gain, while maximising ventilation and optimising daylight integration. The building envelop is unique and developed for this purpose.

Urban environment

    The site is a short distance from the main road, although it does not have views towards it. Therefore, it is sufficiently secluded, giving opportunities for opening of spaces, natural light and ventilation, without concern for vehicle emissions and particulate matter. 

    The placement of the new residence corresponded to where an existing residence was sited. The old residence was demolished, because it was in no condition for renovation. Therefore, minimal new ground area was consumed. This allowed the preservation of all existing trees on site and the conscious orientation and amalgamation of the landscape into the design. 

    The internal access path from the entrance to the property to the house is also one that originally existed. In its final detailing the path was paved with perforated blocks that allow grass to grow along the path, while vehicle access and surface water run-off is effectively facilitated for. 

    The indoor play area / badminton court, was a half built structure at the commencement of design process. Therefore, the siting and elevation was utilised as is. The structure was on an adjacent property, later amalgamated as a part of the whole. 

    The microclimate of the immediate context was exploited to the maximum. The shaded and vegetated context was preserved and this allowed the optimum integration of natural light and ventilation. Thereby, together with the renewable energy installation, created a Net-Zero energy building.  

  • 4 222,00 m2
  • 15,00 %
  • 3 572,00



    Electroplastic Engineering Co.(PVT) LTD

    [email protected]

    HVAC, électricité / lighting

    Custom Designed Luminaires. Archt. Dr. Narein Perera and Archt. Shashikala Ranasinghe - Designers

    The Clients - the users of the residence - appreciate the idea of asymmetry and the soft, diffused quality of the light emanated by the luminaires. Fabric as the primary material for the ambient light luminaires works to soften the overall interior and its distinct materiality. The options for task lighting are specifically reduced in scale compared to that of the ambient fixtures. Thus less visible in general areas. All fixtures use LED lamps.

Construction and exploitation costs

  • 580 000,00
  • 5 700,00
  • 505 000
  • The total cost indicated here includes two distinct functional zones - the residence and the extended recreation / entertainment zone. The total cost also includes the complete furnishing of the spaces. All aspects were designed and custom manufactured for the project.
    A distinct advantage was seen in the use and sourcing of materials from the locality, greatly reducing transport costs. Almost all of the major elements of the build was built in-situ, therefore waste was minimised to a maximum. [e.g. timber was sourced as logs from the local (State Timber Corporation), sized such that almost the whole log is utilised, as joists, rafters, timber battens etc.]

Energy bill

  • 130,00

Indoor Air quality

    As a naturally ventilated building the posiibility of CO2 concentration is minimised. Even when fully enclosed the vertical volumes of the spaces help ease any buildup of CO2. 

    All materials used in the interiors is natural and coatings used are all water based. 


    Health and Comfort is deemed a primary concern in the siting, orientation and form making of the building in general and the building envelop in particular. 

    The shaded envelop ensures the direct solar heat gain into the interior spaces are minimised. The envelop itself is again shaded by vegetation adjacent to the building and vegetation on the envelop itself. 

    The verandah spaces outside each internal space and extensive natural ground cover around the building enhance evaporative cooling possibilities. 

    All fenestration is oriented to the north and south, while ensuring the glazed surfaces are shaded, by both building elements and vegetation.

    The lighting of the spaces mimic and incorporate the natural rhythms of the day. Screens of timber and bamboo tat allow the user to control the intensity of light penetrating the spaces. Direct sunlight is avoided by the orientation of the fenestration, but use large opening to capture and integrate daylight, throughout the day.


GHG emissions

  • 80,00 year(s)

Reasons for participating in the competition(s)

  • Passive Approach to Solar heat gain minimisation, ventilation enhancement, evaporative cooling enhancement and reducing conduction - for optimum thermal comfort within spaces. 
  • Building envelop as shade structure - both horizontally and vertically, double skin envelop, and as growing medium for the landscape. 
  • Near Net-zero energy building
  • Local material and human capital emphasised construction processes. Therefore, a low embodied carbon material palette. 
  • Microclimate preservation and enhancement as a basis for successful natural light and ventilation based thermally comfortable spaces.


Building candidate in the category

Energy & Hot Climates

Energy & Hot Climates

Green Solutions Awards 2020-2021
 "Blurred Envelop" Passive Design Sri Lanka Warm Humid Tropics Net-zero energy Low Embodied Carbon Local Material

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narein perera

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Green Solutions Awards 2020-2021