Journal Entry For
Module 3 - Project Goals Targets & Strategies
Note: the preliminary site location for this design is in Massachusetts.
Design Goal Brainstorm:
- net zero energy building (site energy)
- net positive water building
- minimize embodied carbon from building materials
- leverage use of modular and/or prefabricated building systems
- maximize use of passive solar design strategies (minimize reliance on active mechanical systems)
- Build a relatively cost-effective building
- make an accessible and useable community space
Design Goals
Design Goal 1: Net Zero Energy (site energy)
- Design goal
- Over the course of a year of operation, the building show generate as much energy as it uses.
- Measure
- Annual site energy (in kWh or kBtu) and Annual PV generation (in kWh or kBtu)
- Targets
- minimum acceptable target - 90% reduction in energy use intensity of a similar building type and size in MA.
- design target - net zero energy on on annual basis.
- Strategies
- passive solar design techniques (thermal mass, southern facing windows, low-e glazing, trombe walls, sunspaces, natural ventilation with stack effect)
- maximize daylighting (solar tubes, solar shelves)
- all electric heating system (eliminate natural gas/fossil fuel use onsite)
- solar PV (roof, canopy, integrated glass skylights)
- ground source heat pumps
- cool roof
- overhang shading devices
Design Goal 2: Net Positive Water (annually)
- Design goal
- capture as much water as is used onsite on an annual basis.
- Measure
- gallons of water used
- Targets
- minimum acceptable target - 80% reduction in water use intensity of a similar building type and size in MA.
- design target - net zero water on on annual basis
- Strategies
- Rainwater collection infrastructure (tanks, pipes, collection, storm drains)
- grey water system
- in-building water treatment system
- low flow appliances and fixtures
Design Goal 3: Minimize Embodied Carbon
- Design goal
- Choose materials that minimize the environmental impact of producing and constructing those materials (from material extraction through building construction).
- Measure
- Life cycle assessment of key building materials (e.g. structure, finishes, mechanical equipment) with an output of 100-year Global Warming Potential (in lbs or tons of CO2eq released into atmosphere).
- Targets
- Minimum acceptable value = 25% reduction in lbs CO2eq/sf for a typical, similar size building of same type in MA.
- Target value = 50% reduction in lbs CO2eq for a typical, similar size building of same type in MA.
- Strategies
- Choose low carbon structural materials
- mass timber
- if concrete, use mixes that have waste product aggregates (e.g. like fly ash)
- limit the amount of concrete and steel
- limit the amount of aluminum (used for window framing)
Design Goal 4: Cost Effective Design
- Design goal
- Many people associated “Net Zero” anything leads to cost premiums for products and systems. The goal is to use cost as a controlling factor to make this design realistic and not be ridiculously expensive.
- Measure
- Cost per gross SF ($/SF) for building construction.
- Targets
- Minimum acceptable value = limit the building design to cost no more than 50% than a typical commercial/exhibition building in MA.
- Target value = limit the building cost to no more than 35% more than the typical commercial/exhibition building in MA.
- Strategies
- control the amount of glass on the exterior (e.g. where not needed for passive solar design techniques).
- understand $/SF for different types of structure
- Predictable and constructible design to allow for contractor to increase productivity
- keep spaces similar enough that there are less custom spaces that may decrease productivity
- steer clear of curved glass or custom shapes where possible
- use prefabricated products where applicable to gain efficiencies onsite.