Ecologic and sustainable kindergarten/preschool Hedlunda
Implementation concept submitted by: Nenet/Thomas Greindl, Sweco
Region / local area where the pilot is situated: County of Västerbotten, Sweden
Type of building
Use of building: All-day preschool/kindergarten/daycare center for the age of 1-7 years
Total effective area: BBR (Swedish system to count the area) 1580 m2
PHI (for the Passive House certificate) 1323 m2
Number of levels above earth: 2 levels preschool, 1 level restaurant and kitchen
Source of energy for heating: District heating with renewable fuel, with only use of returning district heat water
Type of heating system: Under floor heating system
Type of water heating system: Energy from the district heating system (returning water) and from the energy recovery of the food cooling- and freezing units of the restaurant and kitchen
Type of ventilation system: Passive House certified central ventilation systems with heat recovery system and an effective heat recovery rate of 86%. Exhausted air from the kitchen will be cleaned with Ozone to reduce cooking odours and grease before the heat recovery is possible in a normal ventilation unit.
Owner and costs
Name of owner: Umeå municipally
Date of construction: 2013/2014
Total cost: 41.000.000 SEK, project costs, building included all fixed equipment and furniture for preschool, kitchen and restaurant
Financing resources: Public money
Short description of the pilot project
In 2020, Umeå region aims at being world leading in sustainable building in cold climate. This and the EPBD were driving factors for the City of Umeå for developing a lighthouse projec in building the northernmost certfied passive house. It will also be BREEAM-certified, a unique combination so far in Sweden. The project is developed together with the municipal operator to suit for their Reggio Emilia inspired education. The use of ecological, nonpoisonous building materials is decisive as well as long-living building and easy to change appliances. It is about ressource-efficiency and the target is to create a building with a negative CO2-banlance in a 50-year-lifecycle. 4 options of building design have been tested with LCC method, resulting in a concept which will meet the following criteria:
- Specific space heating demand ≤ 15 kWh/(m2,a)
- Total specific primary energy demand ≤ 120 kWh/(m²a)
- -87% reduction of heating demand and -80% of total energy demand compared to building code
- Airtightness Pressure test result, n50≤ 0.3 h‾¹ or 0,15 l/(sec, m²)
Expected lessons to be learned
How to implement political decision on sustainability in reality.
Giving input to a process in defining national criteria and rating systems for sustainable buildings, not at least linked to possible funding mechanism.
Quality of location and facilities
Hedlunda preschool are situated on a municipal lot, distance to the city centre about 1km. The new building is replacing a old one, thereby not leading to additional soil sealing. The area is well connected and easily accessible by sustainable transport modes (cycling, public transport).
Process and planning quality
The process started with a 2-step architect comptetion in 2011, in which one part was about planning a passive house. No more environmental targets and goals have been set in the competition.
The winning Sweco-concept included already the use of renewable nonpoisonous building materials, meeting sustainable certification criteria and a zero-energy-concept.
The concept has been optimized in a step-by-step process together with the responsible municipal departments which resulted in a decision to go for a flagship project and the use well-known international certification systems
b) Objectives for energetic measures
Accordingly to the Passive House Certification C riteria for:
- Specific space heating demand ≤ 15 kWh/(m2,a)
- Total specific primary energy demand *) ≤ 120 kWh/(m²a)
- Airtightness Pressure test result, n50≤ 0.6 h‾¹ (here n50≤ 0.3 h‾¹ or 0,15 l/(sec, m²)
All energy calculations have been done with the Passive House Planning Package (PHPP) which is the key design tool used when planning a Passive House and as such, serves as the basis of verification for the Passive House Standard.
c) Standardized calculation of economic efficiency
4 different building from standard/building code going to the most ambitious passive house design have been calculated with LCC method, while using the following basic parameter:
- Price district heating: 0,5 kr/kWh
- Price electricity: 0,8 kr/kWh
- Increase energy price per year 5%
- Interest rate 4%
- Timeline 50 år
The calculation showed that the international passive house design had the lowest lifecycle costs.
d) Product management – use of low emission products
All building materials have to fulfill the following limits for emissions to air:
TVOC according to EN 16000-5/6/9 < 300 μg/m3
VOCaccording to EN 16000-5/6/9 < 100 μg/m3
Formaldehyd according to EN 16000-2 < 48 μg/m3 = 0,048 mg/m3 = 0,04 ppm
Radon < 50 Bq/m3
CO₂ < 900 ppm
All building material is documented in a digital register incl. type, name, producer, content, delivery note and where used. Beyond, a complementing list of which materials are not allowed has been developed and is in use.
e) Planning support for energetic optimization
All energy calculations have been done with the Passive House Planning Package (PHPP). There is a space allocation plan for the project (which also is used as tabulation for all building materials). Part of PHPP is to take into account of all internal heat gains, passive solar gains, thermal bridges and more.
Part of the planning process was to develop an air tightness concept with detailed drawings and material recommendations. There is also a training of construction workers as the airtight layer may be practiced. In any case will we have two Blower Door tests together with infrared thermography.
f) Information for users
Under the whole planning process meetings every two weeks meetings were held with the project-, building- and the kindergarten management. All of them have been involved in the process, the concept, the floor plans, the function of the building and the selection of materials and equipment.
A large display in the entrance area will shows the current and the average annual energy consumption. An alarm bell will sounds in the school kitchen when the present power consumption of the kitchen appliances exceeds the calculated power consumption.
On part of the BREEAM certification is the creation of a user manual for all of the user.
Implementation of service package
Still under discussion, as the final way of adapting the service package in Sweden is not decided yet.
Energy and Utilities
a) Specific heating demand
Accordingly to the Passive House Certification Criteria for
- Specific space heating demand ≤ 15 kWh/(m2,a)
- Total specific primary energy demand *) ≤ 120 kWh/(m²a)
- Airtightness Pressure test result, n50≤ 0.6 h‾¹ (here n50≤ 0.3 h‾¹ or 0,15 l/(sec, m²)
b) Specific cooling demand
There is no cooling demand because of the temporary exterior sun protection with external venetian blinds. As a heat shield in the summer and additional insulation in the winter, the external venetian blinds improve the energy balance of building.
The adapted automated slat control ensures that external venetian blinds meet the requirements for energy efficiency class A.
Additionally, there is a bus-system that coordinate the sun shading systems, ventilation, heating, with each other to be able to react effectively to external weather influences. An ice and a direction dependent wind monitoring exists as well.
c) Specific lighting demand
Demand controlled LED lights whith daylight- and occupancy sensors which are cooperating with the exterior venetian blinds with concave light control slats.
d) Primary energy demand
Total specific primary energy demand *) ≤ 120 kWh/(m²a)
Reduced primary energy demand through following measures:
- reduce the heating demand to around 15 kWh/(m2a) = intern. Passive house standard.
- demand controlled ventilation units with sensors for humidity, VOC, CO₂ and temperature
- avoidance of cooling demand through temporary sunshade systems, naturally night ventilation concept.
- reduce the use of electricity for artificial light, pumps and fans
- reduce the use of hot water and the losses of the hot water circuit
- use of the returning water of the district heating grid
- use of district heating grid with a CHP system (combined heat and power coupling)
and a PEF between 0,8 (from my research) and 0,26 (data of Umeå Energy) - use of district heating grid which use 48% biomass and 38% waste as fuel (2012)
- energy-saving professional kitchen equipment and reuse of the waste heat from refrige- und freeze storage rooms
e) Renewable energy
District heating with renewable fuel, with use of returning district heat water and from the energy recovery of the food cooling- and freezing units of the restaurant and kitchen
Health and Comfort
a) Thermal comfort in summer
Good thermal comfort in summer guaranteed by
- use of a exterior temporary sunshade systems
- the ventilation system sucks in the fresh air on the cool north side
- a naturally ventilation strategy to cool the building by night in summertime
b) Ventilation – non energetic aspects
Part of the sustainability and quality program in the project are these sound pressure levels (there is a control before the building will get permission to use):
LA,eq < 30 dB (A) Kindergarten group rooms
LA,eq < 25 dB (A) Rest rooms
LA,eq = effective sound pressure
Building materials and constructions
All building materials have to fulfill the following limits for emissions to air:
TVOC according to EN 16000-5/6/9 < 300 μg/m3
VOCaccording to EN 16000-5/6/9 < 100 μg/m3
Formaldehyd according to EN 16000-2 < 48 μg/m3 = 0,048 mg/m3 = 0,04 ppm
Radon < 50 Bq/m3
CO₂ < 900 ppm
All building material is documented in a digital register incl. type, name, producer, content, delivery note and where used. Beyond, a complementing list of which materials are not allowed has been developed and is in use.
Furthermore it is not allowed:
to use HFC´s in the production process of XPS insolation under the ground slap.
to use insolation panels with brominated flame retardants
to use PVC pipes for wastewater and conduits
to use refrigerants with ODP > 0 and GWP > 5 in cold storage systems.
All chiller, freezer, cooler in the professional kitchen use as an environmentally friendly refrigerant CO2.
a) Avoidance of PVC
- It is not allowed to use PVC pipes for wastewater and conduits.
- No floor coverings are used. Instead use of linoleum, wood parquet and tiles.
- Certified Passive House windows, doors and curtain walls are made of wooden frames with aluminum cladding.
- The exterior venetian blinds are made of aluminum.
- Ventilation pipes are made of galvanized sheet metal.
b) Ecological optimization of building materials
All materials need an EPD, a sustainable certificate and a report for emissions. The variety and numbers of materials has been reduced and renewable, emission free building provisions produced as closed as possible to the building side were preferred. The results of comparative LCA is the use of:
- Wooden beams
- cellulose insulation (without Borax)
- OSB 3 panels without Formaldehyde
- Wood fibre insulation board
- Ceilings with glued laminated timber
- Glued laminated timber for bearing construction
- Linoleum floors
- Wooden parquet
- Wooden panels
- Wooden frames for doors and windows
- Paintings with very low emissions
Evaluation and follow up
According to the joint evaluation guidelines and using interviews with the involved parties in the project as well as the continuous discussion of the project by the RCC.
Contact project owner
Organisation: Umeå Kommun Fastighet /property management
Projectmanagement: Umeå kommun
Christer Svärling
Christer.Svarling@umea.se
0046-(0)70-6606493
Thomas Greindl
Sweco Architects Umeå
Thomas.greindl@sweco.se
0046(0)76-8290156