Posts tagged building envelope

The Theresa Passive House: A Blueprint for High-Performance Design in Hot-Humid Climates

The Theresa Passive House, nestled in Austin's historic Clarksville neighborhood, stands as a remarkable example of how architectural preservation can harmoniously merge with modern sustainable design. This 2100 square foot residence, completed in 2020, is not merely a renovation and addition to a 1914 Craftsman bungalow; it is a meticulously engineered dwelling that embodies rigorous targets in energy efficiency, indoor air quality (IAQ), thermal comfort, embodied carbon, and responsible materials sourcing.[1] These ambitious goals were established by the Passive House Institute U.S. (Phius), a leading authority in high-performance building standards.

Architectural Design, Building Enclosure, Building Science, Code, Dehumidification, Electrification, Environmental Design, Filtration, Healthy Home, Heat Pumps, High Performance Homes, HVAC, Indoor Air Quality, Mechanical Design, Passive House, Phius, Solar, VentilationPositive EnergyMay 28, 2025Theresa Passive House, high-performance design, hot-humid climates, residential performance, sustainable design, architectural preservation, energy efficiency, indoor air quality (IAQ), thermal comfort, embodied carbon, responsible materials sourcing, Passive House Institute U.S. (Phius), Phius certification, PHIUS 2018+ Source Zero, ASHRAE Climate Zone 2A, photovoltaic panels, battery backup systems, self-sufficiency, resilience, Forge Craft Architecture + Design, Hugh Jefferson Randolph Architects, Studio Ferme, integrated design process, building envelope, HVAC system, on-site solar panels, MEP (Mechanical, Electrical, Plumbing) engineering, Positive Energy, building science, human-centered design, net-zero energy buildings, heating loads, cooling loads, source energy, airtightness, energy modeling, continuous insulation, thermal bridges, air changes per hour (ACH@50 Pa), air leakage, Blower Door Test, high-performance windows, triple-glazing, low-emissivity (low-e) coatings, Solar Heat Gain Coefficient (SHGC), balanced ventilation, Energy Recovery Ventilators (ERVs), dedicated dehumidification, right-sizing mechanical systems, comfort, health, durability, passive survivability, Winter Storm Uri, University of Texas research, climate-specific standards, moisture management, key performance metrics, site energy use index (EUI), renewable energy production, wall assemblies, water control layer, air control layer, thermal control layer, vapor control layer, wood frame system, mineral wool insulation, unvented roof, Marvin windows, indoor pollutants, combustion products, Volatile Organic Compounds (VOCs), particulate matter (PM2.5), ASHRAE Standard 62.2, ventilation rates, Variable Refrigerant Flow (VRF) heat pump AC, Panasonic Intellibalance 1000 ERV, MERV filtration, heat pump hot water heater, climate resilience, extreme weather events, grid outages, source zero certification, community education, AIA Housing Award, Passive Project of the Year – Retrofit, Austin Green Awards, affordable multifamily housing, building envelope prioritization, mechanical ventilation with energy recovery (ERV) implementation, MEP systems integration, advanced air filtration, MERV ratings, active energy independence, photovoltaics, battery storage, MEP engineer collaboration, climate-specific MEP solutions, commissioning agent

Marfa Ranch

The Marfa Ranch is a distinguished residential project by Lake Flato Architects, is thoughtfully situated on a low rise within the expansive, pristine desert grasslands of Marfa, Texas. This unique location, nestled between the Chihuahuan Desert and the majestic Davis Mountains, presents a challenging yet profoundly beautiful environment. The architectural design of the ranch consciously adopts a low profile, comprising eight distinct structures meticulously organized around a central courtyard. This layout, shaded by native mesquite trees, serves as a cool respite from the sun-drenched desert beyond its walls, drawing inspiration from the area's earliest regional architectural traditions. Architect Bob Harris of Lake Flato articulated that the design embodies a "deliberate quality of spareness that matches the qualities of the land," emphasizing the importance of the house maintaining a low profile to merge seamlessly with the terrain while simultaneously opening to distant views and providing crucial protection from the region's harsh winds and intense sun. This project has garnered significant recognition, including the 2022 Texas Society of Architects Design Award and its inclusion in Dezeen's Top 10 Houses of 2022.

Architectural Design, Building Enclosure, Building Science, Environmental Design, Healthy Home, High Performance Homes, HVAC, Indoor Air Quality, Mechanical Design, Natural Building Material, VentilationPositive EnergyMay 28, 2025Marfa Ranch architecture, applied building science, Chihuahuan Desert environment, Lake Flato Architects, residential project design, courtyard layout, regional architectural traditions, low profile design, Bob Harris (Lake Flato), spareness of design, Texas Society of Architects Design Award, Dezeen Top 10 Houses of 2022, climate-responsive architecture, vernacular architecture, thermal mass, passive cooling, rammed earth walls, modern building science, MEP engineering, building envelope consultants, Positive Energy (MEP firm), human-centered design, healthy spaces, comfortable spaces, resilient spaces, building envelope, MEP systems, integrated design approach, thermal mass definition, specific heat capacity, diurnal temperature ranges, thermal lag, R-value, moisture resilience, Portland cement stabilization, compressive strength, longevity of rammed earth, hydrophobic additives, drainage, slab edge, moisture management, thermal conductivity, moisture content, hygric buffering, density of rammed earth, thermal lag hours, compressive strength of rammed earth, lifespan of rammed earth, R-value of insulated rammed earth, rammed earth wall performance attributes, air barrier, air pressure differences, energy loss prevention, moisture issues prevention, interstitial condensation, indoor air quality, controlled ventilation, mechanical ventilation, Energy Recovery Ventilators (ERVs), Indoor Air Quality (IAQ) definition, IAQ impacts on health, IAQ pollutants (particulate matter, VOCs, combustion byproducts), ASHRAE standards, green-certified buildings, cognitive function, passive building strategies, ventilation strategies, filtration strategies, humidity control strategies, source control strategies, MERV rating, whole-house fresh air systems, local exhaust systems, humidity range, low-VOC materials, combustion safety, holistic MEP design, hydronic heating system, VRF heating/cooling system, resilient design, sustainable water management, water scarcity, groundwater contamination, water conservation, greywater capture, onsite water storage, adaptive reuse (water tank to pool), rainwater collection, building science principles, durable wall assemblies, Energy Recovery Ventilators (ERVs) for IAQ, early collaboration between architects and engineers, healthier buildings, resilient buildings, positive Energy's mission, Kristof Irwin

The Case for Dedicated Dehumidification In Sealed Attics

Modern building design increasingly embraces sealed attic construction as a strategy to enhance energy efficiency and improve air leakage control, particularly beneficial for the performance of HVAC ductwork. This approach, where the attic space is brought within the building's thermal and air control envelope, fundamentally alters the moisture dynamics compared to traditional vented attics. While offering significant advantages, sealed attics introduce unique moisture challenges that demand precise and active management to prevent long-term durability issues and maintain superior indoor air quality.

Building Science, Architectural Design, Building Enclosure, Dehumidification, Healthy Home, Filtration, High Performance Homes, HVAC, Indoor Air Quality, Mechanical DesignPositive EnergyMay 23, 2025Sealed attics, dedicated dehumidification, moisture control, energy efficiency, indoor air quality, HVAC systems, air leakage, building durability, condensation risks, mold growth, air barrier, thermal barrier, insulation, roof deck temperature, building codes (IRC), ASHRAE standards, unconditioned attics, conditioned attics, psychrometrics, vapor control, duct performance, latent load, sensible load, building science principles, dew point, hygric buffering, controlled ventilation, air sealing, maintenance issues, cross-contamination, volatile organic compounds (VOCs), pests, allergens, duct leakage, system strain, pressure balancing, wood framing, sheathing, building envelope, resilience, sustainability, dehumidifier sizing, condensate management, building science experts, MEP engineering.

Designing Healthier Homes by Eliminating Fossil Gas Appliance Emissions

Architects, as the primary designers of our built environment, hold a profoundly influential position in shaping the health and well-being of building occupants. Beyond the critical considerations of aesthetics, structural integrity, and energy performance, a deep understanding of the invisible forces at play within a building's envelope is increasingly paramount. This report aims to equip architects with the essential knowledge to proactively design for superior indoor air quality (IAQ), particularly concerning emissions from common household gas appliances. The decisions made during the design phase, from material selection to mechanical system integration, directly influence the indoor environment and, by extension, the health outcomes of those who inhabit these spaces. This effectively positions architects as critical guardians of public well-being within the built space, expanding their traditional role to encompass a vital public health responsibility.

Indoor Air Quality, HVAC, Electrification, Architectural Design, Building Enclosure, Code, Filtration, Healthy Home, High Performance Homes, VentilationPositive EnergyMay 22, 2025Designing healthier homes, eliminating fossil gas appliance emissions, indoor environmental quality, architect's role, indoor air quality, gas appliances impact on home health, combustion byproducts, hazardous air pollutants, synthesizing scientific findings, actionable strategies for architectural practice, pollutants emitted by gas appliances, health effects, design and engineering solutions, fundamentals of indoor air quality, source control, ventilation, filtration, temperature and relative humidity levels, building as a dynamic system, geographic site, local climate, physical structure, HVAC, construction techniques, contaminant sources, occupants' activities and behaviors, air exchange pathways, mechanical ventilation systems, infiltration, air pressure differences, building envelope, "Building Tight, Ventilate Right" imperative, energy consumption, pollutant concentration, energy efficiency, ventilation strategies, indoor air pollutants exceed outdoor levels, internal pollutant sources, "concentration trap", managing and removing internal contaminants, key pollutants from gas appliances, nitrogen dioxide, carbon monoxide, particulate matter, volatile organic compounds, moisture, respiratory irritation, asthma exacerbation, infection risk, decreased lung function, fatigue, chest pain, impaired vision, headaches, dizziness, confusion, nausea, DNA damage, mortality, transmission of airborne pathogens, organ damage, allergic reactions, cancer, dampness, mold growth, electric coil burners, high-dose exposure, pulmonary edema, diffuse lung injury, bronchitis, ambient air quality standards, carboxyhemoglobin, unvented gas space heaters, gas stoves, back-drafting, angia, poor ventilation, ultrafine particles, respirable particulate matter, cooking emissions, airborne particles, pathogens, respiratory aerosols, formaldehyde, benzene, unburned natural gas leakage, environmental tobacco smoke, automobile exhaust, sensory irritation, carcinogens, moisture load, human respiration and perspiration, bathing, washing, plants, pets, appliance selection, all-electric homes, electronic ignitions, proper appliance installation and maintenance, ducted range hoods, capture efficiency, airflow requirements, multi-family homes, whole-house ventilation strategies, tighter building envelopes, backdrafting risks, make-up air systems, targeted spot exhaust, bathroom fan, high-efficiency filtration, MERV-13, infectious aerosol exposure, cost-benefit analysis, air cleaning, indoor particle concentrations, semivolatile organic compounds, monitoring and alarms, carbon monoxide alarms, advanced IAQ monitors, PM2.5 sources, collaboration with MEP engineers, certified technicians, health impacts, continuous leakage, moisture byproduct, all-electric transition, building a healthier future, works cited, RMI, ASHRAE, EPA, LBNL, ventilation and air cleaning, envelope leakage, hazardous air pollutant emissions, residential ventilation requirements.

Blog