Case study analysis of the material selection process during dwelling design in Flanders Goodmorning everyone, Today I will present a part of my PhD research to you, entitled “case…. Elke MEEX, Elke KNAPEN, Griet VERBEECK Faculty of Architecture and Arts, Hasselt University, Belgium, elke.meex@uhasselt.be

INTRODUCTION Project sustainability level depends on early design decisions Architect = important actor Main focus = energy, environmental impact is gaining importance Decisions based on intuition and experience Move towards more sustainable material choices: shortcuts and rules of thumb are insufficient Goal of PhD = to develop a design-supportive methodology for architects for the assessment and integration of materials with low environmental impact, from the early design phase on Need for knowledge on architects’ current approach for material selection

METHODOLOGY Retrospective case study analysis (14 newly built dwellings) Process mapping of design documentation: When, at what moment of the design process? To what level of detail? Semi-structured interviews with the 9 architects Who decides? Why, on what basis?  Small sample size, not representative, but useful insights

METHODOLOGY Retrospective case study analysis (14 newly built dwellings) Process mapping of design documentation: When, at what moment of the design process? To what level of detail? Semi-structured interviews with the 9 architects Who decides? Why, on what basis?  Small sample size, not representative, but useful insights Separate research paper Focus of today’s presentation

METHODOLOGY Design documentation = Structured into 4 most prevalent design phases in Flanders: Subdivided into six building layers: Building structure (load bearing function) Building skin (visible, exterior) Building shell (mostly insulation) Building systems (technical equipment) Interior space (finishing materials) Room separations (interior walls) Figure based on: Brand, S., How buildings learn: What happens after they're built. 1994, New York: Penguin Group.

METHODOLOGY Design documentation = Degree of specification of material decisions: Material category (= concrete, wood, …) Product type (= generic product with technical specifications, characteristics, performance levels, …) Brand or producer (= specific product) 1) MATERIAL CATEGORY 2) PRODUCT TYPE 3) SPECIFIC PRODUCT/BRAND

METHODOLOGY Semi-structured interviews Conducted in October – November 2015 Scheme completed during interviews: WHO (actors) and WHY (drivers)

STRUCTURE & SEPARATIONS RESULTS Building structure (load bearing function) & room separations (interior walls): Early design = construction type by architect (experience) and client (preference, perception) Detailed design = product by architect, client and structural engineer (in some cases) Execution = brand/producer by contractor and structural engineer, focus on physical aspects Construction type = interplay between architect (experience) and client (preference, perception) SE: considers load bearing capacity and physical aspects CO: considers mostly quality, constructability and rate of return STRUCTURE & SEPARATIONS Time Money Ethical responsibility Influence other parties Legend MOTIVES: Physical characteristics Appearance Subjective Context Culture Legend ACTORS: CL = client AR = architect P = producer / installer EN = energy reporter LG = local government SE = structural engineer CO = contractor

RESULTS Building skin (visible, exterior): Early design = first preference of client (subjective, aesthetic), architect looks at context Prior to permit submission = product specification in cost estimate by architect and client Execution = brand / producer specification, within budget restrictions client Product level in cost estimate (subject to change due to client’s budget restrictions) SKIN Time Money Ethical responsibility Influence other parties Legend MOTIVES: Physical characteristics Appearance Subjective Context Culture Legend ACTORS: CL = client AR = architect P = producer / installer EN = energy reporter LG = local government SE = structural engineer CO = contractor

RESULTS Building shell (mostly insulation): Early design = based on energy target client, architect uses rules of thumb (conventional) Detailed design / tendering = specified more by architect or energy reporter (performance level) Execution = brand specification by contractor, within prescribed performance levels Mostly “traditional” materials, except when clients or some architects have an “ecological” motivation (rare) SHELL Time Money Ethical responsibility Influence other parties Legend MOTIVES: Physical characteristics Appearance Subjective Context Culture Legend ACTORS: CL = client AR = architect P = producer / installer EN = energy reporter LG = local government SE = structural engineer CO = contractor

RESULTS Building systems (technical equipment): Architects lack knowledge, especially on new techniques (heat pump, solar boiler, …) Detailed design = “standard package” of systems proposed by architect, client usually agrees Execution = based on technical knowledge of contractors and installers, within budget client Specification, final choice = Budget is restrictions: sometimes basic systems are installed, replaced by more advanced ones later on SYSTEMS Time Money Ethical responsibility Influence other parties Legend MOTIVES: Physical characteristics Appearance Subjective Context Culture Legend ACTORS: CL = client AR = architect P = producer / installer EN = energy reporter LG = local government SE = structural engineer CO = contractor

RESULTS Interior space (finishing materials): Walls, ceilings: conventional, some architects/clients prefer more ecological/healthy materials Floors: material (and thickness) is assumed by architect during design  final specification by client, advise from architect and producers Budget restrictions: sometimes structure of ceilings and walls in secondary rooms remains unfinished Budget restrictions: first an alternative flooring material, replaced by the final material later on SPACE Time Money Ethical responsibility Influence other parties Legend MOTIVES: Physical characteristics Appearance Subjective Context Culture Legend ACTORS: CL = client AR = architect P = producer / installer EN = energy reporter LG = local government SE = structural engineer CO = contractor

DISCUSSION Who decides which materials to use during building design? Prior to building permit submission: Mainly architect and client Sometimes specialists are involved After building permit submission: Specialists (contractor, producers, …) are actively involved Architect: Is not always final decision maker (= client, in control of budget)  providing advise to the client

DISCUSSION Why, on what basis are material-related decisions made? Budget constraints are present in all kinds of decisions Skin and space (=visible): aesthetics and subjective reasons (taste) Structure, separations, shell and systems (=invisible): physical characteristics, some subjective reasons (perceptions, believes, … ) Ethical drivers: may be due to the context of the interview Remark: in large-scale survey (February 2014) it was found that cost (79%), wishes client (75%), previous experience (73%), personal knowledge (68%) and aesthetics (68%) were the most common drivers in material selection. “Sustainable” drivers were only selected by 10-15% of the architects.

CONCLUSIONS Architects are set in their habits of decision making  need for: More awareness, commitment of architect Reliable information and support on sustainable material selection Knowledge is used in further development of PhD research Further research will be done within PhD: Appropriate default values and assumptions for early design assessment Ways to provide usable and design supportive feedback Desires regarding the tool format …

Thank you for your attention ! Questions ? Research funded by a PhD grant from VLAIO PhD Candidate: Elke Meex Supervisor: Prof. dr. ir. Griet Verbeeck Co-supervisor: dr. Ir. Elke Knapen Faculty of Architecture and Arts – Research Group ArcK – Hasselt University