Relevant Case Studies: A Benchmark for Future Design

Abstract

Active House Alliance proposes a new tool to help designers in the whole construction process, since the architectural concept, through the definition of energetic strategies, until the characterization of material and construction details. The AH Radar guides the design process and, at least, evaluates the project, according to the holistic integration of its three principles: Comfort, Energy, and Environment. This final chapter collects the evaluation of 16 Active House projects, analyzing the design strategies and evaluating them through the criteria of the AH Radar. All those case studies represent real virtuous examples of good design practice, available now.

This chapter is authored by Federica Brunone.

All projects data and information had been provided by Active House Alliance, VELUX Group, and designers, and then edited by the author.

Appendices

Case Study

RenovActive

Location :

Anderlecht, Belgium

Project type :

refurbishment

Use :

social housing complex

Client :

private company

Design :

Antwerpbased architectural firm ONO architectuur, Le Foyer Anderlechtois and VELUX Group

Year :

2017.

RenovActive is more than a building project. It represents a design concept, based on seven strategies, with the aim to achieve the balanced integration of Active House principles with the tight budget framework of a social house, proving the financial viability of Active House renovation. Modularity, flexibility, and scalability of solutions make the prototype become a stereotype, a template for 86 similar renovation projects in the community (Fig. 5.3).

• Comfort

  The renovation starts with the aim to improve the indoor visual and thermal comfort, assuring a pleasant and healthy environment. New, efficient, roof and façade windows, with dynamic solar blinds, help to control excess heat and to reach excellent performances on DF level. They provide also passive solar gains in winter and fresh air in summer, thanks to an automatic window-opening system. It involves the entire dwelling, because of the stack effect through the new stairwell—a respiratory channel. Moreover, temperature, humidity, and CO₂ sensors guarantee optimal indoor air quality, as the ventilation unit control adapts indoor levels to tenants’ needs, in real time, saving energy and avoiding indoor discomfort (Figs. 5.4 and 5.5).

• Energy

  The design process focuses on the evaluation of different scenarios, combining different technical solutions and evaluating them according to the AH Radar and financial sustainability. As the social housing budget does not fit to the high costs (and low reproducibility) of a heat pump and solar collectors, designers decide for an efficient gas condensation boiler, connected to the existing network. Besides, the new insulating layer of the envelope and the floor heating system helps to provide indoor thermal comfort, while reducing the total energy consumption (Fig. 5.4).

• Environment

  According to the environmental sustainability required by AH standards, a 50,00l tank for collecting and recycling rainwater satisfies the flushing toilets, washing machine, and conservation of green spaces needs. Finally, the design concept up-grades to the neighborhood overall refurbishment. It will mean the establishment of a community energy system that could cover the energy needs, through renewable sources energy network (wind turbine, solar and PV panels…) (Fig. 5.4).

  Fig. 5.3

  

  RenovActive (Ph. Adam Mørk)

  Fig. 5.4

  

  RenovActive schematic design and AH Radar (© VELUX Group and AH Alliance)

  Fig. 5.5

  

  RenovActive: on the left, the new bright attic; besides, a night view (Ph. Adam Mørk)

Reborn Home

Location :

Pecs, Hungary

Project type :

refurbishment

Use :

family house

Client :

private

Design and development :

Prof., Ph.D., Dr. Habil István Kisteledgi Dla, Kátái Nóra

Year :

2017.

New functions and spaces for the refurbishment of an existing house in Hungary. The design strategies exploit the existing building features integrating them with new designing choices about the envelope and systems (Fig. 5.6).

• Comfort

  The new envelope includes a south-oriented solar chimney, with a large glass curtain wall and glass roof, which guarantee the achievement of optimal daylighting conditions, even in darker spaces. Besides high levels of visual comfort, the thermal comfort is provided by the integration of 36 cm thick eco-wood fiber insulation and external 3-pane glazing windows with radiative surfaces for heating/cooling. They are cladded by a 100% natural thermal-activated plaster, which balances heat and moisture. This approach is integrated with a mechanical ventilation system, for the optimization of VOC and humidity levels. In summer nights, it collaborates with a natural cross ventilation, cooling the inner thermal masses (Figs. 5.7 and 5.8).

• Energy

  The first design strategy is to exploit the thermal mass of the existing 30 cm thick brick wall. The envelope strategies are combined with the system ones. In winter, two 100 m deep geothermal probes work with a heat pump, while the air handling unit recovers the 90% of the heat/cooling production, by a 30 m long earth-soil heat exchanger. In summer, a passive cooling strategy is applied through natural cross ventilation. A solar thermal collector provides 100% DHW. Moreover, 10,00l hot-water and 875l cool-water tanks ensure high efficiency in heating/cooling, by storing energy. A PV-system is located on the new roof, whose 27° slope assures a maximum yield of solar electricity by 3.5 kWp. Thus, the primary energy consumption in winter is 22.82 kWh/m² year, saving up to 70%. Finally, a smart management system controls heating/cooling, mechanical ventilation, and DHW (Fig. 5.7).

• Environment

  In order to save the existing construction, almost 100% of the load-bearing structure has been preserved, with a positive influence on LCA validation. The existing reinforced concrete slabs and brick-walls are integrated by 100% natural adobe plaster, and wood fiber insulation. Metal roofing and insulation slabs replace existing toxic materials. A 27 m³ cistern collects water from the roof, which is recycled for washing and cooking, by using a reversed osmosis water filter (Fig. 5.7).

  Fig. 5.6

  

  Reborn Home Street front view of the dwelling with entrance and garage (Ph. The Greypixel Workshop)

  Fig. 5.7

  

  Reborn Home schematic design and AHRadar (© Kistelegdi and Active House Alliance)

  Fig. 5.8

  

  Reborn Home solar chimney for passive ventilation, night cooling in summer and for high visual comfort levels all over the year (Ph. The Greypixel Workshop)

Copenhagen International School

Location :

Copenhagen, Denmark

Project type :

new project

Use :

educational building

Client :

private foundation

Design :

C.F.Møller Architects

Year :

2017.

Copenhagen International School (CIS) is a private educational institute, whose cladding system represents the largest European BIPV—Building Integrated Photovoltaic. Its installation takes the building into the Danish ForskVE/EUPD project, based on the promotion of renewable sources and high energy-efficiency (Fig. 5.9).

• Comfort

  Several international studies attest that natural light is essential for educational activities because it helps to improve focus and learning abilities. Therefore, the CIS’ façades present an average ratio of 20% windows area over floor area, providing good levels of daylight. Moreover, a LED lighting system adds artificial light, if needed. Besides the visual comfort, the thermal well-being is assured by indoor temperatures of 21–26 °C, thanks to good insulation, heating/cooling and heat-recovery ventilation systems. The last one provides high air exchange, achieving good levels of air-quality, according to AH directives: almost all the rooms present ≤350 ppm levels over the outdoor CO₂ concentration (Figs. 5.10 and 5.11).

• Energy

  The overall final energy demand is 15 kWh/m²y, representing a virtuous sample among the standard average demand of Danish school buildings. The well- insulated envelope—U-values of 0.74, 0.1, 0.11 and 0.12 W/m²K, respectively of windows, external walls, roof and ground floor—defines 10.4 kWh/m² as the actual heating use, covered by the Central district system. Besides, the electricity supply for yearly operation (13.4 kWh/m²) is guaranteed by both the local grid and the 6000 m² BIPV system (annual production = 10.7 kWh/m²). Its modules are 60 W green chromatic coated hardened glass panels (700 × 716 mm), tested in a wind tunnel to certify the noise reduction. Considering all the contributions, renewable energy sources supply 69% energy demand, with a final energy consumption of 6.7 kWh/m² year (Fig. 5.10).

• Environment

  The design strategies of CIS lead it to become an example of a Nearly Zero Energy Building, whose definition declares high energy-efficiency and renewable sources use, with a consequent lower environmental impact. In addition to the BIPV system, the district heating and cooling systems of Copenhagen and the Danish electrical grid—almost covered by green energy sources (respectively 58% and 50%)—supply the energy demand of the building, helping to lower the CO₂ emissions.

  Fig. 5.9

  

  Copenhagen International School (Ph. Adam Moerk)

  Fig. 5.10

  

  Copenhagen International School: FLD values for a type-classroom and AH Radar—under validation (© KUBEN Management and AH Alliance)

  Fig. 5.11

  

  CIS: on the left, the new bright attic; on the right, a panoramic view (retrieved from https://www.cis.dk/); in the center, the pitched PV panels (Ph. Peder Vejsig Pedersen)

Active House Erasmushove

Location :

Den Haag, Netherlands

Project type :

new construction

Use :

family house

Client :

private end user

Design :

Klimaatbouw

Year :

2017.

Active House Erasmushove is an Active House since the very first design sketches. It has an educative purpose to act as an example for architects, consultants, and end-users: more than 150 people visited the building site to learn about its design principles and technical solutions, during the construction phase (Fig. 5.12).

Fig. 5.12

Active House Erasmushove (Ph. Bas Hasselaar)

• Comfort

  Comfort was the leading design principle, with both ample daylight and ventilation grills from at least two directions in every main room. The layout of the house is optimized to benefit maximally from passive natural resources. The kitchen is the main living part of the house. It is a large, two-storey open space of the South/West part of the house (for the evening sun and warmer temperatures), and with windows on three sides. Bedrooms are North/East located, to access to the morning sun while remaining cooler during the day. Daylight is allowed to penetrate deeply into the house (DFaverage > 5%). This enables stack natural ventilation in summer, supplying fresh air to prevent uncomfortable drafts. Every room is equipped with a CO₂-based extraction of stale air and has its own thermostat (Figs. 5.13 and 5.14).

  Fig. 5.13

  

  Active House Erasmushove daylight factor simulation, via VIZ Daylight Visualizer and AH Radar (© Bas Hasselaar and AH Alliance)

  Fig. 5.14

  

  Active House Erasmushove: on the left, the open space kitchen and living room; on the right, the southern façade, the green roof and the PV-integrated roof (Ph. Bas Hasselaar)

• Energy

  The building envelope is well insulated, with R-values of floor, walls, and ceilings respectively at 5.0, 6.5 and 8.0 m²K/W and triple glazed surfaces. Location and sizing of windows are optimized for maximum passive solar gains in winter and minimal overheating in summer. Heat comes from stale ventilation air through an air/water heat pump. It is helped by outdoor air, extracted from the cavity underneath the integrated PV panels, on roof. The heating system exploits a water-based capillary floor, walls and/or ceilings (depending on room), for a low-temperature radiative heating. A smart home system monitors all energy flows, whose preliminary results suggest a positive energy profile for 10 months per year (Fig. 5.13).

• Environment

  The main load-bearing construction comes from cellular concrete, which has 1/4 of the standard concrete environmental loads. Inner walls are plastered with adobe; outer wall cladding consists of douglas timber, treated with biobased Scandinavian paint. The windows and glass are Cradle to Cradle certified. Horizontal roof surfaces feature a green roof to catch rainwater and improve biodiversity. Freshwater consumptions are less than half of the average in The Netherlands.

Great Gulf Active House Centennial Park

Location :

Etobicoke, Toronto, Ontario, Canada

Project type :

new construction

Use :

single detached residential house

Client :

private user

Design :

Architectural and technological design project Superkul, HomeCAD, HVAC Designs, Building Knowledge, Quail Engineering, Brockport (Home Technology), Velux Denmark, Great Gulf

Year :

2016.

Great Gulf AH Centennial Park is the first certified Active House in the world. It is beyond the current energy performance criteria, of the Ontario Building Code 2012. Design simulations and a monitoring campaign enhance the feasibility of a new low-energy and environmental-friendly way of healthy living (Fig. 5.15).

• Comfort

  Great Gulf AH Centennial Park is an example of qualitative and quantitative optimization of technology and design. The C-shaped courtyard has a double-height open plan, where natural light and breeze overwhelm the indoor space, providing great spaciousness and visual connection. DF simulations and as-built monitored data confirm optimal levels of visual comfort (min. 2.2%), thanks to suntunnels and skylights. Large windows facilitate the stack effect, reducing the energy demand to the HVR unit for summer cooling, while triple-glasses manage solar gains. At least, all those products are sensored and remote controlled by automatic technology and users, to adapt indoor conditions to tenants’ comfort needs (Figs. 5.16 and 5.17).

• Energy

  Holistic efficiency is the key word to explain the project strategies. The compactness of the building minimizes heat losses, while well-insulated and air-tight prefab building components provide an adiabatic shell for extreme seasons. The HVAC system distinctly controls thermal comfort and air quality in each room, avoiding energy waste. As the energy demand is minimized, its supply is demanded to a combination of heat pump and gas furnace. A local green energy provider assures 100% renewable sources, such as wind and hydroelectricity. Thus, the building output optimal performance levels if compared to Canadian standards (Fig. 5.16).

• Environment

  The LCA calculation has validated the project from the production to the end-of-life phases, considering how renewable sources positively influence the environmental impact of the use-phase. GreenHouse requirements on faucets, toilet flushes and washing machines help to achieve 57% freshwater saving potential. At least, more than the 89.5% of building material has a recycling potential, and 80% of wooden products (by weight) could show SFI certifications (Fig. 5.16).

  Fig. 5.15

  

  Great Gulf AH Centennial Park (Ph. Shai Gil Fotography)

  Fig. 5.16

  

  Great Gulf AH Centennial Park DF analysis and AH Radar (© Great Gulf and AH Alliance)

  Fig. 5.17

  

  Great Gulf AH Centennial Park indoor spaces and details (Ph. Shai Gil Fotography)

Green Solution House

Location :

Bornholm, Denmark

Project type :

refurbishment and new construction

Use :

public building—offices

Client :

private

Design :

Architectural design Kasper Guldager Jensen—3XN, Steenbergs Tegnestue, SLA, GXN innovation; Engineering design Ramboll, COW; Developer Trine Richter, Hotel Ryttegården AH monitoring LEAPCRAFT

Year :

2015.

Green Solution House (GSH) is a conference center, whose project consists of the renovation of an existing building, through the AH vision of a new, sustainable, healthy, comfortable and creative environment (Fig. 5.18).

Fig. 5.18

Green Solution House (Ph. Adam Mørk)

• Comfort

  In living and working spaces, natural light is essential to provide visual comfort and high productivity, reducing energy consumption for artificial light. Thus, in GSH sun-tunnels and light cables, skylights and huge fenestration assure well-lit spaces and high daylight levels everywhere (e.g. DF = 6.6% in the conference room). Moreover, the substitution of existing concrete railings with glass surfaces improves daylight conditions for hotel rooms. Besides, a green wall and specific finishing materials clean and purify indoor air, absorbing pollutant particles and balancing humidity levels. A mechanical/natural ventilation system guarantees indoor thermal comfort, through permeable acoustic panels, which diffuse air from the ceiling, with a reduction of duct sizes and performing as radiative cooling (Figs. 5.19 and 5.20).

  Fig. 5.19

  

  Green Solution House FLD distribution and AH Radar, which compares the existing building and the renovation project, highlighting the optimization process of the AH parameters (© Teknologisk Institut and AH Alliance)

  Fig. 5.20

  

  GHS under construction (Ph. Laura Starner) and interior details (Ph. Adam Mørk)

• Energy

  According to the educational purpose, GSH has an interactive learning tool by LEAPCRAFT, which allows to visualize energy fluctuations and to understand the correlation between users’ behavior and consequent variations of energy consumption and environmental impact. This tool has recorded data from the as-built phase to the users’ interaction one, calculating an average of 3.33 kWh/m² as first-year energy performance. Besides, the energy demand is 2200 kWh/year, whose 32.3% comes from renewable sources. Global energy requirements are satisfied by exchanges with Bornholm local grid; floor heating/cooling are supplied on-site, by a thermal energy system partly based on food leftovers recycle. Moreover, south-located glasses are equipped with PV-cells that produce 5000 kWh/year (Fig. 5.19).

• Environment

  Inspired by a Cradle to Cradle life cycle concept and circular sustainability, GSH is the results of assembled solutions, whose materials and products have been inquired through an LCA perspective and certified for they recyclability (nearly 50% of total) and social responsibility of resource use. This process has been validated by DGNB.

OptimaHouse

Location :

Kiev, Ukraine

Project type :

new construction

Use :

family house

Client :

private

Design :

Architectural and energy design Arch. Alexander Kucheravy; Automatization and systems Schneider Electric; Structural design and construction Dostupne Zhytlo Construction materials Metrotile, Velux, Veka, Saint-Gobain, Manezh

Year :

2015.

OptimaHouse is a two-floor compact modern house, whose envelope and systems design is conceived with a holistic approach, aiming the optimal solutions in living comfort, energy efficiency, environmental impact, construction, and cost (Fig. 5.21).

• Comfort

  OptimaHouse reaches high scores in each AH comfort parameter. The envelope has the 31.5% of windows to total building area, providing natural light, solar gains in cold seasons and allowing obtaining a DF of 3–5% in living spaces. A hybrid ventilation system of natural cross-ventilation in middle seasons and the HVAC for heating/cooling periods, the air-air heat pump, the “water floor” and electrical ceramic panels guarantee an operative air temperature of not less than 21 °C in the cold period and not more than 24 °C in the hot period. The hybrid ventilation ensures also not less than 900 ppm of CO₂ concentration, thank sensors that measure inside temperature, humidity, CO₂ concentration, control the opening/closing of roof windows, the HVAC and sent information to occupants (Figs. 5.22 and 5.23).

• Energy

  The integrated design of OptimaHouse assures an energy demand less than 60 kWh/m² year—65% less than a traditional building in Ukraine. This achievement is due to several choices, such as the compactness of the building, its optimal orientation to the sun and insulation (U_wall = 0.15 W/m²K, U_roof = 0.09 W/m²K, U_floor = 0.09 W/m²K, U_roofwind. = 1.28 W/m²K, U_{facade wind.} = 1.0 W/m²K), and the high efficient air-air heat pump. The energy demand is 45% covered by renewable sources, strictly integrated to the building: 24 vacuum solar tubes satisfy the 86% of hot water demand and the 10% for floor heating, while 6 integrated roof PV panels (2.3 m³ polycrystalline silicon cells) produce 360 kWh/year of electric energy (Fig. 5.22).

• Environment

  OptimaHouse environmental impact is minimized, in terms of both consumptions than recycled potential. CO₂ emissions are less than 7 kg/m²year, while freshwater consumption is reduced to 25% if compared to local legislation standards. Besides, the recycled content for all building is more than the 30%, and FSC label certifies the local origin of 80% timber products and components.

  Fig. 5.21

  

  Optimahouse (Ph. Alexander Kucheravy)

  Fig. 5.22

  

  Optimahouse schematic design and AH Radar (©Alexander Kucheravy)

  Fig. 5.23

  

  Optimahouse details: on the left, the different material treatment of the building's envelope, according to sun exposition; on the right, a detail of the 6 integrated roof PV panels (Ph. Alexander Kucheravy)

Haus am See

Location :

San Felice del Benaco, Italy

Project type :

new construction

Use :

family house

Client :

private

Design :

Arch. Eileen Meyer

Year :

2014.

Haus am See is a two-storey private residence in the northern Italian surrounding of the Garda Lake. The aim to best fit the building into the natural landscape lead the design strategies, which focus on the AH principles integration, beyond the passive house standards. The result is a Net Zero Energy Building and the first Italian AH, with a residential use (Fig. 5.24).

• Comfort

  Visual comfort is the first requirement that has been pursued, in terms of both daylight supply and panoramic view on the surrounding landscape. This disposition shapes the interior spaces organization and the envelope of the building, as the north façade is transparent and heading towards the lake. Besides, looking for a direct relationship with nature and, thus, better human well-being fits with a passive cooling strategy in summertime, reducing the energy consumption. Moreover, a domotic orientable shading system helps to keep the correct daylight factor in each indoor space. At least, a mechanical ventilation system controls the air quality, in terms of CO2 and humidity concentration (Figs. 5.25 and 5.26).

• Energy

  Haus am See follows the holistic approach that integrates architecture, technology, and system design, to achieve the minimization of energy demand, in all seasons. While in summer, natural ventilation provides passive cooling, in winter the building shape and technical details guarantee to minimize the heat-losses, as validated by the blower door test (n50 = 0.22 h⁻¹). At least, the overall energy use for heating, cooling, hot water, ventilation and electricity is 42 kW/m² year (supplied by PV panels on the roof), as calculated and monitored for more than one year (Figs. 5.25 and 5.26).

• Environment

  As the attachment to the place of the site has come over the entire project, the designer decides for local handcrafted and traditional construction materials, as bricks and concrete. This choice leads to a significant contribution to a better indoor climate, thanks to the inertial properties of massive materials. Moreover, the proximity to the site has reduced the global emission of the construction works. In addition, wooden products used for floor and windows frames have FSC certificates (Fig. 5.25).

  Fig. 5.24

  

  Haus am See (Ph. Arch. Eileen Meyer)

  Fig. 5.25

  

  Haus am See: schematic design and AH Radar (©Arch. Eileen Meyer and AH Alliance)

  Fig. 5.26

  

  Haus am See details: on the left, a detailed view of the indoor spaces and finishing materials; on the right, the panoramic view on Garda Lake (Ph. Arch. Eileen Meyer)

House by the Garden of Venus

Location :

Willendorf, Austria

Project type :

refurbishment and enlargement

Use :

family house

Client :

private

Design :

Planning and site supervision Valker Dienst, Inprogress Architektur Consulting and Chistoph Feldbacher; Static Merz kley partner ZT GmbH; Daylight planning VELUX Österreich GmbH; Artificial light planning Podpod design; Building concept Active House Standard; Wooden structure and interior construction Kasper Greber Holz-und Wohnbau GmbH, Tischlerei Herbert Feuerstein, Tischlerei Ing. Gerhard Graschopf GmbH

Year :

2013.

“House on a house” is the architectural concept that fulfills the client’s needs of spatial expansion, despite the high density of the small Willendorf village. That led to a height development, an elongated tympanum that seems to overrun the existing garden on the ground floor and stretch out to the landscape. The design strategies respond to the needs for natural daylight, ventilation, and views (Fig. 5.27).

• Comfort

  The House by the Garden of Venus provides excellent daylight conditions, thanks to the several skylights and the large southern window, which led a large amount of direct sunlight to penetrate during all seasons. The sun screening and awning system and the shape of the external envelope guarantee the solar load reduction in midsummer, while the strategically positioned and automated windows allow a ventilate cooling strategy, that grant internal temperature values under 26 °C. A mechanical ventilation system integrate the cross natural ventilation strategy during the heating period, allowing a CO₂ concentration below 1000 ppm (Figs. 5.28 and 5.29).

• Energy

  The orientation of the existing building and the context constraints do not allow the installation of thermal collectors and/or photovoltaics panels strictly integrated into the building. However, the neighboring building is almost ready to host a solar system, while the heating energy comes from renewable resources, as the timber from the owners’ woods. The wood furnace is going to be substituted by an efficient geothermal heat pump. The total energy consumption for heating, hot water and electricity applications is 50 kWh/m² year (Fig. 5.28).

• Environment

  The upper-storey extension results as an intelligent densification strategy, avoiding a further soil consumption. Besides, a detailed LCA certifies that the building has a low environmental impact, thanks to the water saving fittings and the employment of local wood in the lightweight construction of the new extension. This led the project to achieve the 75% of recyclable materials, at the end of building lifespan (Figs. 5.28 and 5.29).

  Fig. 5.27

  

  House by the Garden of Venus (Ph. Volker Dienst)

  Fig. 5.28

  

  House by the Garden of Venus DF distribution and AH Radar (© AH Alliance)

  Fig. 5.29

  

  House by the Garden of Venus: the indoor space and construction phase (Ph. Jörg Seiler)

Great Gulf Active House

Location :

Toronto, Canada

Project type :

new construction

Use :

family house

Client :

private company

Design :

Architectural project Superkül; Engineering project Enermodal; Developer Great Gulf

Year :

2013.

Great Gulf Active House is the result of the integration between a standard Canadian house design and the innovative AH principles, optimizing traditional architectural aspects and advanced technological devices, to provide human comfort and wellbeing, and energy efficiency while respecting the environment (Fig. 5.30).

• Comfort

  Great Gulf Active House architectural design welcomes the aim to provide a better indoor climate: the gabled roof allows double-height spaces, with a huge amount of natural daylight supply, by skylights and sun-tunnels. While the automated-shading avoid the glare effect, those motorized-opening windows help to achieve an optimal indoor thermal environment, interchanging the mechanical cooling with natural ventilation (until 24 °C as indoor temperature value). At least, the heat recovery ventilation (HVR) system assures the fresh air supply (Figs. 5.31 and 5.32).

• Energy

  The compact shape of the building and its well-insulated and airtight envelope—with low U-value fenestrations—as first define the low energy demands. In addition, the system’s efficiency fulfills the saving-energy equation. A dual-zoned mechanical system, with 97% efficiency, distributes air on all floors, letting occupants adjust independently humidity and temperature values, in each different room. This system is supported by 100% renewable energy strategies, such as the solar gains from hybrid windows and Bullfrog Power energy providing, to manage indoor thermal comfort and electricity demand. Moreover, a recycling process recovers drain water and hot grey water to preheat incoming cold water, helping to reduce the energy demand for domestic hot water. At least, LED devices are installed (Fig. 5.31).

• Environment

  The LCA-calculation has validated the technical solutions of the envelope, while the Canadian SFI (Sustainable Forest Initiative) certifies the recyclable content of wooden products, such as the traditional frame structure. Moreover, the designers calculate that more than 50% of the construction materials would have a recycling potential. At least, a rainwater cistern could collect a large volume of water, thanks to the big roof area. This minimizes the freshwater consumption, with a saving potential of 35%, based on annual rainfall in Ontario values (Figs. 5.31 and 5.32).

  Fig. 5.30

  

  Great Gulf Active House (© Great Gulf)

  Fig. 5.31

  

  GreatGulf AH schematic design and AH Radar (© GreatGulf and AH Alliance)

  Fig. 5.32

  

  Great Gulf Active House: the entrance and the bight indoor space (© Great Gulf)

The Poorters van Montfort

Location :

Montfort, Netherlands

Project type :

refurbishment and volume addiction

Use :

social housing

Client :

private company

Design :

VELUX A/S, Danfoss; Development partners Bouwhulp Groep Architects, Bam Woningbouw; Advisors Nieman Engineering Advisors

Year :

2013.

The Poorters van Montfort is a retrofit initiative held in the Netherlands, which uses the AH protocol to investigate the weaknesses of 10 existing social housings and recover them, upgrading buildings to Active Houses. It proves the balance between initial investments and final energetic, and thus economic, savings (Fig. 5.33).

• Comfort

  The Poorters van Montfort presents more than one solution to improve the indoor comfort. As first, designers focused on remodeling the external envelope: new façade and automated roof windows assure horizontal cross-ventilation and the stack effect, through the stairwell up to the new and widen attic floor. This strategy works for the summer cooling, while in winter a mechanical ventilation system with CO₂ sensors improves indoor air quality levels ([CO₂]_max = 325 ÷ 350 ppm over the outdoor concentration). Still, the large window surfaces assure DF values between 3.6 and 11%, far above the current European standards. At least, sensored and remote-controlled exterior sun-screenings help to manage solar gains (Figs. 5.34 and 5.35).

• Energy

  The energy approach abides by the Trias Energetica, a three-step strategy to design highly energy-efficient constructions. The first step is to reduce the energy demand, by improving the insulation levels of the envelope (U_{fac window} = 0.65 W/m²K, U_{wood fac} = 0.22 W/m²K, U_{brick fac} = 0.27 W/m²K) and installing energy-efficient appliances (hybrid ventilation system and water-to-water heat pump). These solutions lead the building to a 57.12% reduction in the energy demand. The second and third step involves the energy supply, by on-site renewable sources, such as solar thermal collectors (4.5 m² on the new roof surface) or PV solar cells (19.5 m²), or by off-site high-efficient conversation processes (e.g. cogeneration). At least, 63.9 kWh/m² year are supplied by 100% renewable energy, with a surplus of 2.4 kWh/m² year (Fig. 5.34).

• Environment

  Aiming an eco-friendly impact, this project follows three key-criteria: zeroing the non-renewable energy consumption, minimizing global warming and acidification potential, and the freshwater consumption. According to these purposes, an LCA analysis reveals that just the production processes of the existing building materials released 1/3 of CO₂ and 2/3 of SO₂ and NO_X emissions (Fig. 5.34).

  Fig. 5.33

  

  The Poorters van Montfort (Ph. Adam Mørk)

  Fig. 5.34

  

  The Poorters van Montfort schematic design and AH Radar (© VELUX Group and AH Alliance)

  Fig. 5.35

  

  The Poorters van Montfort: the new attic space (Ph. Adam Mørk)

Haus am Moor

Location :

Krumabach, Austria

Project type :

new construction

Use :

private residence and studio

Client :

private

Design :

Architectural design Berardo Bader Architects; Engineering design Gerhard Bilgeri; Daylight analysis Donau-Universität Krems and VELUX Group

Year :

2012.

A unique wooden volume stretches through the moor, between countryside and village, to host a living and working space under the same roof. Regional architectural elements and natural, untreated materials are combined into the design, aiming high comfort, energy efficiency and respect for the environment (Fig. 5.36).

• Comfort

  The need for a unique building to host a private residence and an attached studio puts daylight availability and indoor visual comfort as the first investigated aspects. Thus, the daylight distribution has been evaluated both through virtual simulations and a physical model at the “Lichtlabor” of the Donau-Universität Krems. Skylights provide the zenithal illumination and allow achieving 3.5 ÷ 4.9% levels of DF. Besides, the big fenestrations on the façade bring users directly into nature. At the same time, the roof windows, the shape, and height of the wooden ceiling guarantee the stack effect, to assure natural cross ventilation and indoor air quality. At last, the hyper-insulated wooden envelope and the high-performant glasses of windows help to maintain indoor thermal comfort, all over the year (Figs. 5.37 and 5.38).

• Energy

  A brine water heat pump with a floor heating and a central wood-burning hearth deliver the required heat. According to this sustainable and eco-friendly approach, designers decided to use different natural materials: while timber envelope provides a good insulation level, the massive cement-based walls stock heat, during cold seasons. Besides, a mechanical ventilation system recovers heat in winter, to minimize energy waste; it turns off in hotter seasons when the opening of windows activates the natural ventilation, to allow a passive cooling and discharge massive walls from thermal overloads. The total energy requirement is 25 kWh/m² year (Fig. 5.37).

• Environment

  The integration with the natural surrounding is the key point of this project. Materials, construction process, products have been chosen because of that. The envelope is furnished with untreated timber, derived from local pines. The floor slabs are produced from locally unearthed clay, which is dried on-site and pressed to form special-shaped bricks that host the heat pipes. Using local materials helps to reduce “grey energy” and CO₂ emissions, due to a long way transportation (Fig. 5.37).

  Fig. 5.36

  

  House on the Moor (Ph. Jörg Seiler)

  Fig. 5.37

  

  House on the Moor DF distribution and AH Radar (© Jörg Seiler and VELUX Group)

  Fig. 5.38

  

  House on the Moor in visually connected with the outdoor environment, gaining direct and diffuse daylight (Ph. Adolf Bereuter)

ISOBO Aktiv

Location :

Sandned, Norway

Project type :

new construction

Use :

family house

Client :

private company

Design :

Architectural concept SFAS|arkitektur Project management Jadarhus AS by Kurt Hobberstad Partners VELUX Norge AS

Year :

2011.

ISOBO Aktiv is an innovative design approach to develop and build low-energy houses. It uses demo-buildings to test different technical solutions on full-scale, and define the measures that more influence indoor climate, energy and environment (Fig. 5.39).

• Comfort

  Optimal indoor comfort depends by high levels of daylight and air quality. ISOBO Aktiv demo-house is equipped with strategically placed roof windows, which double the natural light provided by vertical fenestrations and allow the stack effect of natural ventilation. An automated steering system remotely controls sunscreens, to prevent overheating and glare effect, windows opening, for natural cross ventilation, and heating devices, to optimize indoor thermal conditions. On one side, users could be every time connected with the building, by their own smartphone; on the other one, the house could be monitored, in its performances (Figs. 5.40 and 5.41).

• Energy

  Extra insulation and tightness of the construction envelope, and active strategies on systems—based on renewable sources—assure the achievement of A++, as energy rating for buildings. The envelope represents a full-scale experiment to test several possible technical solutions, with U-values between 0.10 kWh/m²K (of super-insulated external walls and sloped roof) and 1.00 Wh/m²K of roof windows. Thus, the performances about heat leakages have been tested on the finished house, recording a value of N50 = 0.35/h. Besides, 8 m² solar collectors, 8 solar cell panels, an air-to-water heat pump, with heat recovery, supply almost 90% of required energy (44.4 kWh/m² year). A ground collector under the house helps the ventilating unit, increasing its efficiency and naturally heating/cooling the conditioned air (Fig. 5.40).

• Environment

  The house is based on timber-frame construction system, industrially produced and prefabricated. All construction units were delivered as pre-cut and ready-for-assembly. This choice helped to reduce construction waste because all the components have been specifically designed, through an optimized process. Local partners and suppliers minimized long-distance transportation, and consequent CO₂ emission during the construction phase (Fig. 5.40).

  Fig. 5.39

  

  Isobo Aktiv (© Jadarhus AS)

  Fig. 5.40

  

  Isobo Aktiv schematic design and AH Radar (© Jadarhus AS and AH Alliance)

  Fig. 5.41

  

  Isobo Aktiv details: on the left, the indoor bright space, thanks to huge roof windows; on the right, the solar panels and collectors on the roof, which provide almost the 60% of required enrgy (© Jadarhus AS)

Sunlighthouse

Location :

Pressbaum, Austria

Project type :

new construction

Use :

family house

Client :

private company

Design :

Architectural concept HEIN-TROY Architekten; Energy conceptstructural calculations and ecological evaluations Donau-Universität Krems and Institute for Healthy and Ecological Buildings; Building development VELUX Group

Year :

2010.

Sunlighthouse is the first Austrian carbon-neutral single-family house, thus fulfilling Model Home 2020 aims. Its iconic sloping roof combines interesting space definition with high levels of indoor comfort and energy efficiency, taking advantage of the sun for daylight and renewable energy supply (Fig. 5.42).

• Comfort

  According to its name, Sunlighthouse design focuses on the potential to catch sunlight as daylight and heat primary source. Thus, the position of roof and façade windows aims to strategically provide the best visual comfort and to maximize solar gains and natural ventilation. 72 m² glass area guarantee 5% DF in living and working spaces. Actually, this choice help to reduce the artificial light need and to limit the use of HVAC system just during winter. In middle and hot seasons, an automated remote control system regulates the opening/closing of windows and blinds, fostering the stack effect and the indoor global comfort (Figs. 5.43 and 5.44).

• Energy

  Sunlighthouse annual energy demand is 50.8 kWh/m² year, thanks to technical solutions and high efficient products (U_w,roof = 1.1 W/m²K, U_w,façade = 0.76 W/m²K, U_wall = 0.13 W/m²K, U_roof = 0.12 W/m²K). This requirement is satisfied just by renewable energy sources: a highly efficient brine/water heat pump, thermal solar collectors, PV solar cells system and highly energy-efficient appliances guarantee an annual energy surplus of 12.2 kWh/m² year. This means that until 30 years after construction, the house will be a real carbon neutral building. The required energy will be balanced by the clean energy produced by systems (Fig. 5.43).

• Environment

  Sunlighthouse perfectly fits its surroundings. The building outdoor and indoor shapes, its finishing and overtures on the envelope testify the deep connection with the Vienna woods and mountains environment. Moreover, in order to prove the positive-energy and eco-friendly design (CO₂-neutrality and ecological materials), Sunlighthouse has been monitored in its use-phase by VELUX Austria, Danube University Krems and the Austrian Institute for Healthy and Ecological Building (Fig. 5.43).

  Fig. 5.42

  

  Sunlighthouse (Ph. Adam Mørk)

  Fig. 5.43

  

  Sunlighthouse schematic design and AH Radar (© VELUX Group and AH Alliance)

  Fig. 5.44

  

  Sunlighthouse: the bright indoor spaces and the outdoor peculiar shape (Ph. Adam Mørk)

Green Lighthouse

Location :

København, Denmark

Project type :

new construction

Use :

office building

Client :

private company

Design :

Architectural project Christensen & Co Architects; Engineering project Cowi Developer Danish University and Property Agency

Year :

2009.

As a showpiece for the UNI Climate Change Conference of Copenhagen, 2009, Green Lighthouse is the first Danish public CO₂-neutral building, which is hosting the Faculty of Science of the University of Copenhagen. It belongs to the six demo-houses of the Model Home 2020 project, whose aim is the optimal balance between architectural quality, healthy indoor climate, and energy efficiency (Fig. 5.45).

• Comfort

  Green Lighthouse conveys combined architectonic and sustainable solutions. Thanks to its circular atrium space, it hosts an internal passage of light and lets natural cross ventilation, through the house from the roof windows. The main parameter that rules the design of this internal core was the DF, at least 3% in all the working stations and 2% in hallways. The result is an active energy saving strategy, where lux sensors and dimmer controls detect the inner level of naturally provided light and communicate with the electric system to set the power of artificial LED lights. In this way, visual comfort and daylight are provided, with a four times reduction of energy consumption (Figs. 5.46 and 5.47).

• Energy

  In order to maximize the energy saving, Green Lighthouse integrate architecture materials and light into an overall plan. It consists of a combination of renewable sources: district heating, solar cells, solar heating and cooling and seasonal storage. Solar collectors on the roof and the geothermal heat system in the ground convey 35% of energy via heat pump, while 65% of it comes from the eco-friendly district heating, which shares the 35% of renewable energy. At least, 76 m² PV cells guarantee electricity for lighting, hybrid ventilation, and pumps. This energy concept leads to 75% energy consumption cut-off (30 kW/m²/year), and thus it represents a model for office buildings, to become CO₂ neutral construction of the future (Figs. 5.46 and 5.47).

• Environment

  The path of the sun and its movement around the house inspires the architectural concept. This choice emphasizes how sunlight is considered as the most significant energy sources of the building, driving the definition of system devices and, finally, leading to a neutralization of CO₂ emission (Fig. 5.46).

  Fig. 5.45

  

  Green Lighthouse (Ph. Adam Mørk)

  Fig. 5.46

  

  Green Lighthouse schematic design and AH Radar (© VELUX Group, AH Alliance)

  Fig. 5.47

  

  Green Lighthouse details: the bright and circular atrium space and the solar devices on the roof (Ph. Adam Mørk)

Home for Life

Location :

Aarhus, Denmark

Project type :

new construction

Use :

family house

Client :

private company

Design :

Architectural project AART A/S; Engineering project Esbensen Rådgivende Ingeniører; Executive developer VELFAC & VELUX Group

Year :

2009.

Home for Life belongs to the six experimental demo-houses of the Model Home 2020 project by VELUX Group. It aims to demonstrate the feasibility of climate neutral constructions, with a high level of livability (Fig. 5.48).

• Comfort

  An automated system records data from heat, CO₂ and humidity sensors, to control the active envelope and systems. The slate-covered façade is a dynamic screen that changes its status according to climate variations. Thanks to the wide window area—40% of the floor surface, the external envelope opens to daylight, solar gain and natural ventilation in mid and hot seasons, or becomes an adiabatic layer, against winter losses. Besides, the control system manages the fresh air needs, through mechanical ventilation with heat recovery in winter, and auto-opening windows in summer. These technologies upgrade the bioclimatic design of building shape and windows orientation, according to residents’ needs, visual comfort, and energy optimization (shutters and blinds regulate solar heat and avoid the risk of glare) (Figs. 5.49 and 5.50).

• Energy

  As a proper AH, Home for Life produces more energy than it consumes. Within almost 40 years since its construction, the energy surplus of 9 kWh/m²/yr will balance the entire lifecycle amount of energy. To pursue this goal, a holistic approach design qualitative (shape, orientations) and quantitative (dimensions, technical features) parameters (Fig. 5.49). Remote controlled fenestrations and shading system optimize light, air and heat gain, achieving about 50% of heating requirements by passive solar heat in winter. Natural and mechanical ventilation ensure fresh air in any season. 50 m² solar cells, 7 m² solar collectors, and a heat pump produce electrical energy, hot water, and space heating. At least, the control system optimizes energy consumption, scheduling systems use just when they are needed.

• Environment

  Durable and low emissions materials and renewable energy-based systems help to reduce the environmental impact of the house, while the measured data improve the simulated performances (Fig. 5.49). Actually, the combination of natural and advanced technological solutions makes it be a CO₂ neutral building.

  Fig. 5.48

  

  Home for Life (Ph. Adam Mørk)

  Fig. 5.49

  

  Home for Life schematic design and AH Radar (© VELUX Group and AH Alliance)

  Fig. 5.50

  

  Home for Life details: on the left, the bright interior spaces, where the wide windows let the view of the surrounding landscape; on the right, the active façade, covered by black slates, which integrate the dark surfaces of the PV cells and solar panels (Ph. Adam Mørk)